docbrown/app/javascript/crayons/MarkdownToolbar/__tests__/markdownSyntaxFormatters.test.js

import {
  markdownSyntaxFormatters,
  getNewTextAreaValueWithEdits,
} from '../markdownSyntaxFormatters';

describe('markdownSyntaxFormatters', () => {
  describe('inline formatters', () => {
    describe('bold', () => {
      it('Formats selected text as bold, keeping selected text highlighted', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one **two** three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats an empty selection as bold, keeping cursor inside formatting', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one ****two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(6);
        expect(newCursorEnd).toEqual(6);
      });

      it('Unformats a selection that starts and ends with bold formatting', () => {
        const textAreaValue = 'one **two** three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 11,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as bold, when only the start of the selection already has bold formatting', () => {
        const textAreaValue = 'one **two three';
        const expectedNewTextAreaValue = 'one ****two** three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '**two',
        );
      });

      it('Formats a selection as bold, when only the end of the selection already has bold formatting', () => {
        const textAreaValue = 'one two** three';
        const expectedNewTextAreaValue = 'one **two**** three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two**',
        );
      });

      it('Unformats a selection when text immediately before and after have bold formatting', () => {
        const textAreaValue = 'one **two** three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 11,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as bold, when only the text immediately before already has bold formatting', () => {
        const textAreaValue = 'one **two three';
        const expectedNewTextAreaValue = 'one ****two** three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 6,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as bold, when only the text immediately after already has bold formatting', () => {
        const textAreaValue = 'one two** three';
        const expectedNewTextAreaValue = 'one **two**** three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['bold'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });
    });

    describe('italic', () => {
      it('Formats selected text as italic, keeping selected text highlighted', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one _two_ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats an empty selection as italic, keeping cursor inside formatting', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one __two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(5);
        expect(newCursorEnd).toEqual(5);
      });

      it('Unformats a selection that starts and ends with italic formatting', () => {
        const textAreaValue = 'one _two_ three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as italic, when only the start of the selection already has italic formatting', () => {
        const textAreaValue = 'one _two three';
        const expectedNewTextAreaValue = 'one __two_ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '_two',
        );
      });

      it('Formats a selection as italic, when only the end of the selection already has italic formatting', () => {
        const textAreaValue = 'one two_ three';
        const expectedNewTextAreaValue = 'one _two__ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two_',
        );
      });

      it('Unformats a selection when text immediately before and after have italic formatting', () => {
        const textAreaValue = 'one _two_ three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 5,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as italic, when only the text immediately before already has italic formatting', () => {
        const textAreaValue = 'one _two three';
        const expectedNewTextAreaValue = 'one __two_ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 5,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as italic, when only the text immediately after already has italic formatting', () => {
        const textAreaValue = 'one two_ three';
        const expectedNewTextAreaValue = 'one _two__ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['italic'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });
    });

    describe('code', () => {
      it('Formats selected text as code, keeping selected text highlighted', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one `two` three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats an empty selection as code, keeping cursor inside formatting', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one ``two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(5);
        expect(newCursorEnd).toEqual(5);
      });

      it('Unformats a selection that starts and ends with code formatting', () => {
        const textAreaValue = 'one `two` three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as code, when only the start of the selection already has code formatting', () => {
        const textAreaValue = 'one `two three';
        const expectedNewTextAreaValue = 'one ``two` three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '`two',
        );
      });

      it('Formats a selection as code, when only the end of the selection already has code formatting', () => {
        const textAreaValue = 'one two` three';
        const expectedNewTextAreaValue = 'one `two`` three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two`',
        );
      });

      it('Unformats a selection when text immediately before and after have code formatting', () => {
        const textAreaValue = 'one `two` three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 5,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as code, when only the text immediately before already has italic formatting', () => {
        const textAreaValue = 'one `two three';
        const expectedNewTextAreaValue = 'one ``two` three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 5,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as code, when only the text immediately after already has code formatting', () => {
        const textAreaValue = 'one two` three';
        const expectedNewTextAreaValue = 'one `two`` three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['code'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });
    });

    describe('underline', () => {
      it('Formats selected text as underline, keeping selected text highlighted', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one <u>two</u> three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats an empty selection as underline, keeping cursor inside formatting', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one <u></u>two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(7);
        expect(newCursorEnd).toEqual(7);
      });

      it('Unformats a selection that starts and ends with underline formatting', () => {
        const textAreaValue = 'one <u>two</u> three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 14,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as underline, when only the start of the selection already has underline formatting', () => {
        const textAreaValue = 'one <u>two three';
        const expectedNewTextAreaValue = 'one <u><u>two</u> three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 10,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '<u>two',
        );
      });

      it('Formats a selection as underline, when only the end of the selection already has underline formatting', () => {
        const textAreaValue = 'one two</u> three';
        const expectedNewTextAreaValue = 'one <u>two</u></u> three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 11,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two</u>',
        );
      });

      it('Unformats a selection when text immediately before and after have underline formatting', () => {
        const textAreaValue = 'one <u>two</u> three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 7,
          selectionEnd: 10,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as underline, when only the text immediately before already has underline formatting', () => {
        const textAreaValue = 'one <u>two three';
        const expectedNewTextAreaValue = 'one <u><u>two</u> three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 7,
          selectionEnd: 10,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as underline, when only the text immediately after already has underline formatting', () => {
        const textAreaValue = 'one two</u> three';
        const expectedNewTextAreaValue = 'one <u>two</u></u> three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['underline'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });
    });

    describe('strikethrough', () => {
      it('Formats selected text as strikethrough, keeping selected text highlighted', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one ~~two~~ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats an empty selection as strikethrough, keeping cursor inside formatting', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one ~~~~two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(6);
        expect(newCursorEnd).toEqual(6);
      });

      it('Unformats a selection that starts and ends with strikethrough formatting', () => {
        const textAreaValue = 'one ~~two~~ three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 11,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as strikethrough, when only the start of the selection already has strikethrough formatting', () => {
        const textAreaValue = 'one ~~two three';
        const expectedNewTextAreaValue = 'one ~~~~two~~ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '~~two',
        );
      });

      it('Formats a selection as strikethrough, when only the end of the selection already has strikethrough formatting', () => {
        const textAreaValue = 'one two~~ three';
        const expectedNewTextAreaValue = 'one ~~two~~~~ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two~~',
        );
      });

      it('Unformats a selection when text immediately before and after have strikethrough formatting', () => {
        const textAreaValue = 'one ~~two~~ three';
        const expectedNewTextAreaValue = 'one two three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 6,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as strikethrough, when only the text immediately before already has strikethrough formatting', () => {
        const textAreaValue = 'one ~~two three';
        const expectedNewTextAreaValue = 'one ~~~~two~~ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 6,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('Formats a selection as strikethrough, when only the text immediately after already has strikethrough formatting', () => {
        const textAreaValue = 'one two~~ three';
        const expectedNewTextAreaValue = 'one ~~two~~~~ three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['strikethrough'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });
    });

    describe('link', () => {
      it('inserts placeholder link, and highlights url when no selection is given', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one two [](url)three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 8,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'url',
        );
      });

      it('inserts link markdown, and highlights url when selected text does not begin with http:// or https://', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one [two](url) three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'url',
        );
      });

      it('inserts link markdown, and places cursor inside [], when selected text begins with http://', () => {
        const textAreaValue = 'one http://something.com three';
        const expectedNewTextAreaValue = 'one [](http://something.com) three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 24,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(5);
        expect(newCursorEnd).toEqual(5);
      });

      it('inserts link markdown, and places cursor inside [], when selected text begins with https://', () => {
        const textAreaValue = 'one https://something.com three';
        const expectedNewTextAreaValue = 'one [](https://something.com) three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 25,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(5);
        expect(newCursorEnd).toEqual(5);
      });

      it('removes link markdown when no text selected, cursor inside [], and markdown formatting present', () => {
        const textAreaValue = 'one [](url) three';
        const expectedNewTextAreaValue = 'one  three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 5,
          selectionEnd: 5,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(4);
        expect(newCursorEnd).toEqual(4);
      });

      it('removes link markdown when placeholder url is selected, and full markdown formatting present, no link description', () => {
        const textAreaValue = 'one [](url) three';
        const expectedNewTextAreaValue = 'one  three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 7,
          selectionEnd: 10,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(4);
        expect(newCursorEnd).toEqual(4);
      });

      it('removes link markdown when placeholder url is selected, and full markdown formatting present, link description present', () => {
        const textAreaValue = 'one [something](url) three';
        const expectedNewTextAreaValue = 'one something three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 16,
          selectionEnd: 19,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'something',
        );
      });

      it('removes link markdown when selected text is a url and full markdown formatting present, no link description', () => {
        const textAreaValue = 'one [](http://example.com) three';
        const expectedNewTextAreaValue = 'one http://example.com three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 7,
          selectionEnd: 25,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'http://example.com',
        );
      });

      it('removes link markdown when url is selected, and full markdown formatting present, link description present', () => {
        const textAreaValue = 'one [something](http://example.com) three';
        const expectedNewTextAreaValue = 'one something three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 16,
          selectionEnd: 34,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'something',
        );
      });

      it('removes link markdown when full markdown syntax is selected, preserving link description', () => {
        const textAreaValue =
          'one [text description](http://example.com) three';
        const expectedNewTextAreaValue = 'one text description three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 42,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'text description',
        );
      });

      it('removes link markdown when full markdown syntax is selected, preserving URL if link description does not exist', () => {
        const textAreaValue = 'one [](http://example.com) three';
        const expectedNewTextAreaValue = 'one http://example.com three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 26,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'http://example.com',
        );
      });

      it('removes link markdown when full markdown syntax is selected, preserving no content if no link description exists, and URL is placeholder', () => {
        const textAreaValue = 'one [](url) three';
        const expectedNewTextAreaValue = 'one  three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['link'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 11,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(4);
        expect(newCursorEnd).toEqual(4);
      });
    });

    describe('embed', () => {
      it('inserts embed syntax and place cursor inside embed syntax, when no selection is given', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one two {% embed  %}three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['embed'].getFormatting({
          value: textAreaValue,
          selectionStart: 8,
          selectionEnd: 8,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('inserts embed syntax and highlights text, when text is selected', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one {% embed two %} three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['embed'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('removes embed syntax, when cursor is inside empty embed syntax', () => {
        const textAreaValue = 'one {% embed  %} two';
        const expectedNewTextAreaValue = 'one  two';
        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['embed'].getFormatting({
          value: textAreaValue,
          selectionStart: 13,
          selectionEnd: 13,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(4);
        expect(newCursorEnd).toEqual(4);
      });

      it('removes embed syntax and highlights the selected text, when selected text is inside embed syntax', () => {
        const textAreaValue = 'one {% embed random-selected-text %} three';
        const expectedNewTextAreaValue = 'one random-selected-text three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['embed'].getFormatting({
          value: textAreaValue,
          selectionStart: 13,
          selectionEnd: 33,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'random-selected-text',
        );
      });

      it('removes embed syntax and highlights the text, when full embed syntax is selected', () => {
        const textAreaValue = 'one {% embed https://example.com %} three';
        const expectedNewTextAreaValue = 'one https://example.com three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['embed'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 35,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'https://example.com',
        );
      });
    });
  });

  describe('multiline formatters', () => {
    describe('orderedList', () => {
      it('formats a single line selection as an ordered list', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n1. two\n three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. two',
        );
      });

      it('formats multiple lines of text as an ordered list', () => {
        const textAreaValue = 'one\ntwo\nthree';
        const expectedNewTextAreaValue = '1. one\n2. two\n3. three\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 13,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. one\n2. two\n3. three',
        );
      });

      it('inserts an empty list when no selection is provided', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n1. \ntwo three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('unformats a single line of text if selection starts with ordered list format', () => {
        const textAreaValue = 'one\n1. two\nthree';
        const expectedNewTextAreaValue = 'one\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 10,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('unformats a single line of text if no selection is given, and current line start contains 1.', () => {
        const textAreaValue = 'one\n\n1. two\nthree';
        const expectedNewTextAreaValue = 'one\n\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 9,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(6);
        expect(newCursorEnd).toEqual(6);
      });

      it('unformats multiple lines of text if every line starts with ordered list format', () => {
        const textAreaValue = '1. one\n2. two\n3. three';
        const expectedNewTextAreaValue = 'one\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 22,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          expectedNewTextAreaValue,
        );
      });

      it("formats as an ordered list if at least one line of selection doesn't match ordered list format", () => {
        const textAreaValue = '1. one\ntwo\n3. three';
        const expectedNewTextAreaValue = '1. 1. one\n2. two\n3. 3. three\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 19,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. 1. one\n2. two\n3. 3. three',
        );
      });

      it("doesn't add new lines before list, if at the beginning of text area", () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '1. one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. one',
        );
      });

      it('adds one new line before list, if directly preceded by a single new line', () => {
        const textAreaValue = '\none';
        const expectedNewTextAreaValue = '\n\n1. one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 1,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. one',
        );
      });

      it('adds two new lines before list, if no new lines already exist before it', () => {
        const textAreaValue = 'one two';
        const expectedNewTextAreaValue = 'one \n\n1. two\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. two',
        );
      });

      it("doesn't add a new line after list if one already exists", () => {
        const textAreaValue = 'one\n';
        const expectedNewTextAreaValue = '1. one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. one',
        );
      });

      it('adds a new line after list if none exists', () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '1. one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['orderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '1. one',
        );
      });
    });

    describe('unorderedList', () => {
      it('formats a single line selection as an unordered list', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n- two\n three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- two',
        );
      });

      it('formats multiple lines of text as an unordered list', () => {
        const textAreaValue = 'one\ntwo\nthree';
        const expectedNewTextAreaValue = '- one\n- two\n- three\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 13,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- one\n- two\n- three',
        );
      });

      it('inserts an empty list when no selection is provided', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n- \ntwo three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('unformats a single line of text if selection starts with unordered list format', () => {
        const textAreaValue = 'one\n- two\nthree';
        const expectedNewTextAreaValue = 'one\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('unformats a single line of text if no selection is given, and current line only contains -', () => {
        const textAreaValue = 'one\n\n- \ntwo';
        const expectedNewTextAreaValue = 'one\n\n\ntwo';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 7,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(5);
        expect(newCursorEnd).toEqual(5);
      });

      it('unformats multiple lines of text if every line starts with unordered list format', () => {
        const textAreaValue = '- one\n- two\n- three';
        const expectedNewTextAreaValue = 'one\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 20,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          expectedNewTextAreaValue,
        );
      });

      it("formats as an unordered list if at least one line of selection doesn't match unordered list format", () => {
        const textAreaValue = '- one\ntwo\n- three';
        const expectedNewTextAreaValue = '- - one\n- two\n- - three\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 17,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- - one\n- two\n- - three',
        );
      });

      it("doesn't add new lines before list, if at the beginning of text area", () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '- one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- one',
        );
      });

      it('adds one new line before list, if directly preceded by a single new line', () => {
        const textAreaValue = '\none';
        const expectedNewTextAreaValue = '\n\n- one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 1,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- one',
        );
      });

      it('adds two new lines before list, if no new lines already exist before it', () => {
        const textAreaValue = 'one two';
        const expectedNewTextAreaValue = 'one \n\n- two\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- two',
        );
      });

      it("doesn't add a new line after list if one already exists", () => {
        const textAreaValue = 'one\n';
        const expectedNewTextAreaValue = '- one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- one',
        );
      });

      it('adds a new line after list if none exists', () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '- one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['unorderedList'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '- one',
        );
      });
    });

    describe('heading', () => {
      it('inserts a level 2 heading when no selection given, and no current heading on the same line', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n## \ntwo three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(9);
        expect(newCursorEnd).toEqual(9);
      });

      it('inserts a level 2 heading when text selected and line does not include a heading level', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n## two\n three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(9);
        expect(newCursorEnd).toEqual(12);
      });

      it('changes a level 2 to a level 3 heading when no selection given, and line begins with ##', () => {
        const textAreaValue = 'one\n\n## two\nthree';
        const expectedNewTextAreaValue = 'one\n\n### two\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 11,
          selectionEnd: 11,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(12);
        expect(newCursorEnd).toEqual(12);
      });

      it('changes a level 2 to a level 3 heading when text selected, and line begins with ##', () => {
        const textAreaValue = 'one\n\n## two\nthree';
        const expectedNewTextAreaValue = 'one\n\n### two\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 8,
          selectionEnd: 11,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(9);
        expect(newCursorEnd).toEqual(12);
      });

      it('changes a level 3 to a level 4 heading when no selection given, and line begins with ###', () => {
        const textAreaValue = 'one\n\n### two\nthree';
        const expectedNewTextAreaValue = 'one\n\n#### two\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 12,
          selectionEnd: 12,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(13);
        expect(newCursorEnd).toEqual(13);
      });

      it('changes a level 3 to a level 4 heading when text selected, and line begins with ###', () => {
        const textAreaValue = 'one\n\n### two\nthree';
        const expectedNewTextAreaValue = 'one\n\n#### two\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 9,
          selectionEnd: 12,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(10);
        expect(newCursorEnd).toEqual(13);
      });

      it('removes a heading when no text selected and line begins with ####', () => {
        const textAreaValue = 'one\n\n#### two\nthree';
        const expectedNewTextAreaValue = 'one\n\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 13,
          selectionEnd: 13,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(8);
        expect(newCursorEnd).toEqual(8);
      });

      it('removes a heading when text selected and line begins with ####', () => {
        const textAreaValue = 'one\n\n#### two\nthree';
        const expectedNewTextAreaValue = 'one\n\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 10,
          selectionEnd: 13,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(5);
        expect(newCursorEnd).toEqual(8);
      });

      it("doesn't add new lines before heading, if at the beginning of text area", () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '## one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds one new line before heading, if directly preceded by a single new line', () => {
        const textAreaValue = '\none';
        const expectedNewTextAreaValue = '\n\n## one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 1,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds two new lines before heading, if no new lines already exist before it', () => {
        const textAreaValue = 'one two';
        const expectedNewTextAreaValue = 'one \n\n## two\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it("doesn't add a new line after heading if one already exists", () => {
        const textAreaValue = 'one\n';
        const expectedNewTextAreaValue = '## one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds a new line after heading if none exists', () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '## one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['heading'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });
    });

    describe('quote', () => {
      it('formats a single line selection as a quote', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n> two\n three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> two',
        );
      });

      it('formats multiple lines of text as a quote', () => {
        const textAreaValue = 'one\ntwo\nthree';
        const expectedNewTextAreaValue = '> one\n> two\n> three\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 13,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> one\n> two\n> three',
        );
      });

      it('inserts an empty quote when no selection is provided', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n> \ntwo three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('unformats a single line of text if selection starts with quote format', () => {
        const textAreaValue = 'one\n> two\nthree';
        const expectedNewTextAreaValue = 'one\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('unformats a single line of text if no selection is given, and current line only contains >', () => {
        const textAreaValue = 'one\n\n> \ntwo';
        const expectedNewTextAreaValue = 'one\n\n\ntwo';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 7,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(newCursorStart).toEqual(5);
        expect(newCursorEnd).toEqual(5);
      });

      it('unformats multiple lines of text if every line starts with quote format', () => {
        const textAreaValue = '> one\n> two\n> three';
        const expectedNewTextAreaValue = 'one\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 20,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          expectedNewTextAreaValue,
        );
      });

      it("formats as a quote if at least one line of selection doesn't match quote format", () => {
        const textAreaValue = '> one\ntwo\n> three';
        const expectedNewTextAreaValue = '> > one\n> two\n> > three\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 17,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> > one\n> two\n> > three',
        );
      });

      it("doesn't add new lines before quote, if at the beginning of text area", () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '> one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> one',
        );
      });

      it('adds one new line before quote, if directly preceded by a single new line', () => {
        const textAreaValue = '\none';
        const expectedNewTextAreaValue = '\n\n> one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 1,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> one',
        );
      });

      it('adds two new lines before quote, if no new lines already exist before it', () => {
        const textAreaValue = 'one two';
        const expectedNewTextAreaValue = 'one \n\n> two\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> two',
        );
      });

      it("doesn't add a new line after quote if one already exists", () => {
        const textAreaValue = 'one\n';
        const expectedNewTextAreaValue = '> one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> one',
        );
      });

      it('adds a new line after quote if none exists', () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '> one\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['quote'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '> one',
        );
      });
    });

    describe('codeBlock', () => {
      it('formats a single line selection as a code block', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n```\ntwo\n```\n three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('formats multiple lines of text as a code block', () => {
        const textAreaValue = 'one\ntwo\nthree';
        const expectedNewTextAreaValue = '```\none\ntwo\nthree\n```\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 13,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one\ntwo\nthree',
        );
      });

      it('inserts an empty code block when no selection is provided', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n```\n\n```\ntwo three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('unformats a single line of text if selection is wrapped in a code block', () => {
        const textAreaValue = 'one\n\n```\ntwo\n```\nthree';
        const expectedNewTextAreaValue = 'one\n\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 9,
          selectionEnd: 12,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('unformats multiple lines of text if selection is wrapped in a code block', () => {
        const textAreaValue = 'one\n\n```\ntwo\nthree\n```\nfour';
        const expectedNewTextAreaValue = 'one\n\ntwo\nthree\nfour';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 9,
          selectionEnd: 18,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two\nthree',
        );
      });

      it('unformats if no selection is given, but cursor is wrapped in a code block', () => {
        const textAreaValue = 'one\n\n```\n\n```\ntwo';
        const expectedNewTextAreaValue = 'one\n\n\ntwo';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 9,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('unformats if selection starts and ends with code block formatting', () => {
        const textAreaValue = 'one\n\n```\ntwo\n```\nthree';
        const expectedNewTextAreaValue = 'one\n\ntwo\nthree';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 5,
          selectionEnd: 16,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it("doesn't add new lines before code block, if at the beginning of text area", () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '```\none\n```\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds one new line before code block, if directly preceded by a single new line', () => {
        const textAreaValue = '\none';
        const expectedNewTextAreaValue = '\n\n```\none\n```\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 1,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds two new lines before code block, if no new lines already exist before it', () => {
        const textAreaValue = 'one two';
        const expectedNewTextAreaValue = 'one \n\n```\ntwo\n```\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it("doesn't add a new line after code block if one already exists", () => {
        const textAreaValue = 'one\n';
        const expectedNewTextAreaValue = '```\none\n```\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds a new line after code block if none exists', () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '```\none\n```\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['codeBlock'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });
    });

    describe('divider', () => {
      it('inserts a divider if no selection is given', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n---\n\ntwo three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('inserts any selected text after the divider', () => {
        const textAreaValue = 'one two three';
        const expectedNewTextAreaValue = 'one \n\n---\ntwo\n three';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it('removes the divider if no selected text, and cursor directly preceded by line formatting', () => {
        const textAreaValue = 'one\n\n---\ntwo';
        const expectedNewTextAreaValue = 'one\n\ntwo';
        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 9,
          selectionEnd: 9,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          '',
        );
      });

      it('removes the divider if selected text is directly preceded by line formatting', () => {
        const textAreaValue = 'one\n\n---\ntwo three';
        const expectedNewTextAreaValue = 'one\n\ntwo three';
        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 9,
          selectionEnd: 12,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it("doesn't add new lines before divider, if at the beginning of text area", () => {
        const textAreaValue = 'one';
        const expectedNewTextAreaValue = '---\none\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds one new line before divider, if directly preceded by a single new line', () => {
        const textAreaValue = '\none';
        const expectedNewTextAreaValue = '\n\n---\none\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 1,
          selectionEnd: 4,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });

      it('adds two new lines before divider, if no new lines already exist before it', () => {
        const textAreaValue = 'one two';
        const expectedNewTextAreaValue = 'one \n\n---\ntwo\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 4,
          selectionEnd: 7,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'two',
        );
      });

      it("doesn't add a new line after divider if one already exists", () => {
        const textAreaValue = 'one\n';
        const expectedNewTextAreaValue = '---\none\n';

        const {
          newCursorStart,
          newCursorEnd,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        } = markdownSyntaxFormatters['divider'].getFormatting({
          value: textAreaValue,
          selectionStart: 0,
          selectionEnd: 3,
        });

        const editedString = getNewTextAreaValueWithEdits({
          textAreaValue,
          editSelectionStart,
          editSelectionEnd,
          replaceSelectionWith,
        });

        expect(editedString).toEqual(expectedNewTextAreaValue);
        expect(editedString.substring(newCursorStart, newCursorEnd)).toEqual(
          'one',
        );
      });
    });
  });
});