Create DiscussionLocks (#13905)

* Create DiscussionLocks

* Fix specs

* Update nullify_blank_notes_and_reason

* Update before_validation call

* Updated DiscussionLockPolicy for clarity

* Move permitted_attributes to a constant

* Update route

* Apply suggestions from code review for frontend

Co-authored-by: Suzanne Aitchison <suzanne@forem.com>

* Add title tags

* Wrap unlock confirm in main element

* Wrap flash messages up in div

* Actually fix title tags

* Hide comment reply button when discussion is locked

* Add E2E tests

* Try to fix E2E tests

* Cypress...you work locally but not in CI...why!?

* PR feedback

* Update E2E tests

* More E2E updates 😭

Co-authored-by: Suzanne Aitchison <suzanne@forem.com>

app/controllers/articles_controller.rb

@@ -77,6 +77,7 @@ class ArticlesController < ApplicationController
     authorize @article
 
     @article = @article.decorate
+    @discussion_lock = @article.discussion_lock
     @user = @article.user
     @rating_vote = RatingVote.where(article_id: @article.id, user_id: @user.id).first
     @organizations = @user&.organizations
@@ -195,6 +196,24 @@ class ArticlesController < ApplicationController
     end
   end
 
+  def discussion_lock_confirm
+    # This allows admins to also use this action vs searching only in the current_user.articles scope
+    @article = Article.find_by(slug: params[:slug])
+    not_found unless @article
+    authorize @article
+
+    @discussion_lock = DiscussionLock.new
+  end
+
+  def discussion_unlock_confirm
+    # This allows admins to also use this action vs searching only in the current_user.articles scope
+    @article = Article.find_by(slug: params[:slug])
+    not_found unless @article
+    authorize @article
+
+    @discussion_lock = @article.discussion_lock
+  end
+
   private
 
   def base_editor_assigments

app/controllers/discussion_locks_controller.rb

@@ -0,0 +1,49 @@
+class DiscussionLocksController < ApplicationController
+  before_action :authenticate_user!
+
+  DISCUSSION_LOCK_PARAMS = %i[article_id notes reason].freeze
+
+  def create
+    @discussion_lock = DiscussionLock.new(discussion_lock_params)
+
+    authorize @discussion_lock
+    article = Article.find(discussion_lock_params[:article_id])
+
+    if @discussion_lock.save
+      bust_article_cache(article)
+
+      flash[:success] = "Discussion was successfully locked!"
+    else
+      flash[:error] = "Error: #{@discussion_lock.errors_as_sentence}"
+    end
+
+    redirect_to "#{article.path}/manage"
+  end
+
+  def destroy
+    discussion_lock = DiscussionLock.find(params[:id])
+
+    authorize discussion_lock
+    article = discussion_lock.article
+
+    if discussion_lock.destroy
+      bust_article_cache(article)
+
+      flash[:success] = "Discussion was successfully unlocked!"
+    else
+      flash[:error] = "Error: #{discussion_lock.errors_as_sentence}"
+    end
+
+    redirect_to "#{article.path}/manage"
+  end
+
+  private
+
+  def discussion_lock_params
+    params.require(:discussion_lock).permit(DISCUSSION_LOCK_PARAMS).merge(locking_user_id: current_user.id)
+  end
+
+  def bust_article_cache(article)
+    EdgeCache::BustArticle.call(article)
+  end
+end

app/controllers/profile_pins_controller.rb

@@ -8,9 +8,9 @@ class ProfilePinsController < ApplicationController
     @profile_pin.pinnable_id = profile_pin_params[:pinnable_id].to_i
     @profile_pin.pinnable_type = "Article"
     if @profile_pin.save
-      flash[:pins_success] = "📌 Pinned! (pinned posts display chronologically, 5 max)"
+      flash[:success] = "📌 Pinned! (pinned posts display chronologically, 5 max)"
     else
-      flash[:pins_error] = "You can only have five pins"
+      flash[:error] = "You can only have five pins"
     end
     redirect_back(fallback_location: "/dashboard")
     bust_user_profile

app/controllers/stories_controller.rb

@@ -259,6 +259,7 @@ class StoriesController < ApplicationController
 
     @article_show = true
 
+    @discussion_lock = @article.discussion_lock
     @user = @article.user
     @organization = @article.organization
 

app/models/article.rb

@@ -28,6 +28,8 @@ class Article < ApplicationRecord
   # The date that we began limiting the number of user mentions in an article.
   MAX_USER_MENTION_LIVE_AT = Time.utc(2021, 4, 7).freeze
 
+  has_one :discussion_lock, dependent: :destroy
+
   has_many :mentions, as: :mentionable, inverse_of: :mentionable, dependent: :destroy
   has_many :comments, as: :commentable, inverse_of: :commentable, dependent: :nullify
   has_many :html_variant_successes, dependent: :nullify

app/models/comment.rb

@@ -39,6 +39,7 @@ class Comment < ApplicationRecord
   after_save :synchronous_bust
   after_save :bust_cache
 
+  validate :discussion_not_locked, if: :commentable, on: :create
   validate :published_article, if: :commentable
   validate :user_mentions_in_markdown
   validates :body_markdown, presence: true, length: { in: BODY_MARKDOWN_SIZE_RANGE }
@@ -316,6 +317,12 @@ class Comment < ApplicationRecord
     self.markdown_character_count = body_markdown.size
   end
 
+  def discussion_not_locked
+    return unless commentable_type == "Article" && commentable.discussion_lock
+
+    errors.add(:commentable_id, "the discussion is locked on this Post")
+  end
+
   def published_article
     errors.add(:commentable_id, "is not valid.") if commentable_type == "Article" && !commentable.published
   end

app/models/discussion_lock.rb

@@ -0,0 +1,17 @@
+class DiscussionLock < ApplicationRecord
+  belongs_to :article
+  belongs_to :locking_user, class_name: "User"
+
+  before_validation :nullify_blank_notes_and_reason
+
+  validates :article_id, presence: true, uniqueness: true
+  validates :locking_user_id, presence: true
+
+  private
+
+  def nullify_blank_notes_and_reason
+    # Prevent blank strings from beings saved to the DB
+    self.notes = nil if notes.blank?
+    self.reason = nil if reason.blank?
+  end
+end

app/models/user.rb

@@ -180,6 +180,7 @@ class User < ApplicationRecord
   has_many :comments, dependent: :destroy
   has_many :created_podcasts, class_name: "Podcast", foreign_key: :creator_id, inverse_of: :creator, dependent: :nullify
   has_many :credits, dependent: :destroy
+  has_many :discussion_locks, dependent: :destroy, inverse_of: :locking_user, foreign_key: :locking_user_id
   has_many :display_ad_events, dependent: :destroy
   has_many :email_authorizations, dependent: :delete_all
   has_many :email_messages, class_name: "Ahoy::Message", dependent: :destroy

app/policies/article_policy.rb

@@ -19,6 +19,14 @@ class ArticlePolicy < ApplicationPolicy
     update?
   end
 
+  def discussion_lock_confirm?
+    update?
+  end
+
+  def discussion_unlock_confirm?
+    update?
+  end
+
   def destroy?
     update?
   end

app/policies/discussion_lock_policy.rb

@@ -0,0 +1,21 @@
+class DiscussionLockPolicy < ApplicationPolicy
+  PERMITTED_ATTRIBUTES = %i[article_id notes reason].freeze
+
+  def create?
+    (user_author? || minimal_admin?) && !user_suspended?
+  end
+
+  def destroy?
+    create?
+  end
+
+  def permitted_attributes
+    PERMITTED_ATTRIBUTES
+  end
+
+  private
+
+  def user_author?
+    record.locking_user_id == user.id
+  end
+end

app/views/articles/_full_comment_area.html.erb

@@ -1,4 +1,4 @@
-<% cache("whole-comment-area-#{@article.id}-#{@article.last_comment_at}-#{@article.show_comments}", expires_in: 2.hours) do %>
+<% cache("whole-comment-area-#{@article.id}-#{@article.last_comment_at}-#{@article.show_comments}-#{@discussion_lock&.updated_at}", expires_in: 2.hours) do %>
   <section id="comments" data-updated-at="<%= Time.current %>" class="text-padding mb-4 border-t-1 border-0 border-solid border-base-10">
     <% if @article.show_comments %>
       <header class="relative flex justify-between items-center mb-6">
@@ -16,7 +16,12 @@
         data-commentable-id="<%= @article.id %>"
         data-commentable-type="Article"
         data-has-recent-comment-activity="<%= @article.has_recent_comment_activity? %>">
-        <%= render "/comments/form", commentable: @article, commentable_type: "Article" %>
+
+        <% if @discussion_lock %>
+          <%= render "/comments/discussion_lock_reason" %>
+        <% else %>
+          <%= render "/comments/form", commentable: @article, commentable_type: "Article" %>
+        <% end %>
 
         <div class="comments" id="comment-trees-container">
           <% if @article.comments_count > 0 %>

app/views/articles/discussion_lock_confirm.html.erb

@@ -0,0 +1,35 @@
+<% title("Confirm Discussion Lock") %>
+<main id="main-content" class="crayons-layout crayons-layout--limited-l gap-0">
+  <div class="crayons-card crayons-card--secondary text-styles text-styles--secondary text-padding -mb-1 mx-3 m:mx-6 mt-3">
+    <%= @article.title %>
+  </div>
+  <div class="crayons-card text-padding">
+    <h1 class="crayons-subtitle-1 mb-2">Are you sure you want to lock the discussion on this post?</h1>
+    <p class="fs-l mb-4">
+      Users will not be able to add new comments. This will <em class="fw-bold">not</em> remove
+      existing comments. You can unlock the discussion at any time to allow users to leave comments
+      again.
+    </p>
+
+    <%= form_for @discussion_lock, method: :post do |f| %>
+      <div class="form-group">
+        <%= f.hidden_field :article_id, value: @article.id %>
+        <div class="crayons-field mb-5">
+          <%= f.label :reason, "Reason for locking the discussion (optional) - this will be publicly displayed", class: "crayons-field__label" %>
+          <%= f.text_field :reason,
+                           placeholder: "The reason why you're locking this discussion.",
+                           required: false,
+                           class: "crayons-textfield" %>
+        <div class="crayons-field">
+          <%= f.label :notes, "Notes (optional) - this is only visible to you and admins", class: "crayons-field__label" %>
+          <%= f.text_field :notes,
+                           placeholder: "More details as to why you locked the discussion.",
+                           required: false,
+                           class: "crayons-textfield" %>
+        </div>
+      </div>
+      <%= f.submit "Lock discussion", class: "crayons-btn crayons-btn--danger" %>
+      <a data-no-instant href="<%= dashboard_path %>" class="crayons-btn crayons-btn--ghost">Cancel</a>
+    <% end %>
+  </div>
+</main>

app/views/articles/discussion_unlock_confirm.html.erb

@@ -0,0 +1,39 @@
+<% title("Confirm Discussion Unlock") %>
+<main id="main-content" class="crayons-layout crayons-layout--limited-l gap-0">
+  <div class="crayons-card crayons-card--secondary text-styles text-styles--secondary text-padding -mb-1 mx-3 m:mx-6 mt-3">
+    <%= @article.title %>
+  </div>
+  <div class="crayons-card text-padding">
+    <h1 class="crayons-subtitle-1 mb-2">Are you sure you want to unlock the discussion on this post?</h1>
+    <p class="fs-l mb-4">
+      Users will be able to add new comments. You can lock the discussion at
+      any time to prevent users from leaving comments again.
+    </p>
+
+    <div class="fs-l mb-5">
+      <div class="fw-bold">
+        Reason this discussion was locked (publicly visible):
+      </div>
+      <em>
+        <%= @discussion_lock.reason %>
+      </em>
+    </div>
+
+    <div class="fs-l mb-5">
+      <div class="fw-bold">
+        Notes from when this discussion was locked (only visible to you and admins):
+      </div>
+      <em>
+        <%= @discussion_lock.notes %>
+      </em>
+    </div>
+
+    <%= form_for @discussion_lock, method: :delete do |f| %>
+      <div class="form-group">
+        <%= f.hidden_field :article_id, value: @article.id %>
+      </div>
+      <%= f.submit "Unlock discussion", class: "crayons-btn crayons-btn--danger" %>
+      <a data-no-instant href="<%= dashboard_path %>" class="crayons-btn crayons-btn--ghost">Cancel</a>
+    <% end %>
+  </div>
+</main>

app/views/articles/manage.html.erb

@@ -5,11 +5,15 @@
       <div class="dashboard-manage-nav">
         <a href="/dashboard">Dashboard</a> 👉 Manage Your Post
       </div>
-      <% if flash[:pins_error] %>
-        <h3 class="manage-page-error">Uh Oh! <%= flash[:pins_error] %> 😬</h3>
+      <% if flash[:error] %>
+        <div role="alert">
+          <h3 class="manage-page-error">Uh Oh! <%= flash[:error] %> 😬</h3>
+        </div>
       <% end %>
-      <% if flash[:pins_success] %>
-        <h3 class="manage-page-success"><%= flash[:pins_success] %></h3>
+      <% if flash[:success] %>
+        <div role="alert">
+          <h3 class="manage-page-success"><%= flash[:success] %></h3>
+        </div>
       <% end %>
       <h2>Tools:</h2>
       <p><strong>Experience Level of Post:</strong> Is your post written more for a beginner or an advanced audience?  Adjust this level as a <em>gentle</em> indicator which will help show the post to the people who will benefit the most.
@@ -29,7 +33,7 @@
   </div>
 
   <div class="dashboard-container crayons-layout">
-    <%= render "dashboards/dashboard_article", article: @article, organization: @article.organization, org_admin: @user.org_admin?(@article.organization), manage_view: true %>
+    <%= render "dashboards/dashboard_article", article: @article, discussion_lock: @discussion_lock, organization: @article.organization, org_admin: @user.org_admin?(@article.organization), manage_view: true %>
     <div class="single-article single-article-manage-form-wrapper">
       <%= form_for(RatingVote.new) do |f| %>
         <h2>Experience Level of Post</h2>

app/views/comments/_comment_footer.html.erb

@@ -14,21 +14,23 @@
     </span>
   </button>
 
-  <% if comment.depth < 2 || is_childless %>
-    <a
-      class="actions crayons-btn crayons-btn--ghost crayons-btn--s crayons-btn--icon-left toggle-reply-form mr-1 inline-flex"
-      href="#<%= commentable.path %>/comments/new/<%= comment.id_code_generated %>"
-      data-comment-id="<%= comment.id %>"
-      data-path="<%= commentable.path %>/comments/<%= comment.id_code_generated %>"
-      rel="nofollow">
-      <%= inline_svg_tag("small-comment.svg", aria: true, class: "crayons-icon reaction-icon not-reacted", title: "Comment button") %>
-      <span class="hidden m:inline-block">Reply</span>
-    </a>
-  <% else %>
-    <span class="fs-s inline-flex items-center fs-italic color-base-50 pl-1">
-      <%= inline_svg_tag("small-thread.svg", aria: true, class: "crayons-icon", title: "Thread") %>
-      Thread
-    </span>
+  <% unless @discussion_lock %>
+    <% if (comment.depth < 2 || is_childless) %>
+      <a
+        class="actions crayons-btn crayons-btn--ghost crayons-btn--s crayons-btn--icon-left toggle-reply-form mr-1 inline-flex"
+        href="#<%= commentable.path %>/comments/new/<%= comment.id_code_generated %>"
+        data-comment-id="<%= comment.id %>"
+        data-path="<%= commentable.path %>/comments/<%= comment.id_code_generated %>"
+        rel="nofollow">
+        <%= inline_svg_tag("small-comment.svg", aria: true, class: "crayons-icon reaction-icon not-reacted", title: "Comment button") %>
+        <span class="hidden m:inline-block">Reply</span>
+      </a>
+    <% else %>
+      <span class="fs-s inline-flex items-center fs-italic color-base-50 pl-1">
+        <%= inline_svg_tag("small-thread.svg", aria: true, class: "crayons-icon", title: "Thread") %>
+        Thread
+      </span>
+    <% end %>
   <% end %>
 
 </footer>

app/views/comments/_discussion_lock_reason.html.erb

@@ -0,0 +1,10 @@
+<div id="discussion-lock" class="crayons-notice crayons-notice--warning mb-5" aria-live="polite">
+  The discussion has been locked. New comments can't be added.
+  <% if @discussion_lock&.reason %>
+    <div>
+      <em>
+        <%= @discussion_lock.reason %>
+      </em>
+    </div>
+  <% end %>
+</div>

app/views/dashboards/_dashboard_article.html.erb

@@ -67,6 +67,12 @@
 
     <a href="<%= article.path %>/stats" data-no-instant class="crayons-btn">Stats</a>
 
+    <% if discussion_lock %>
+      <a href="<%= article.path %>/discussion_unlock_confirm" data-no-instant class="crayons-btn">Unlock discussion</a>
+    <% else %>
+      <a href="<%= article.path %>/discussion_lock_confirm" data-no-instant class="crayons-btn">Lock discussion</a>
+    <% end %>
+
     <% if article.published %>
       <span id="pageviews-<%= article.id %>" class="crayons-btn dashboard-pageviews-indicator" data-analytics-pageviews data-article-id="<%= article.id %>">
         <span class="page-views-count">

config/routes.rb

@@ -203,6 +203,8 @@ Rails.application.routes.draw do
 
     resources :liquid_tags, only: %i[index], defaults: { format: :json }
 
+    resources :discussion_locks, only: %i[create destroy]
+
     get "/verify_email_ownership", to: "email_authorizations#verify", as: :verify_email_authorizations
     get "/search/tags", to: "search#tags"
     get "/search/chat_channels", to: "search#chat_channels"
@@ -421,9 +423,11 @@ Rails.application.routes.draw do
                                   constraints: { view: /moderate/ }
     get "/:username/:slug/mod", to: "moderations#article"
     get "/:username/:slug/actions_panel", to: "moderations#actions_panel"
-    get "/:username/:slug/manage", to: "articles#manage"
+    get "/:username/:slug/manage", to: "articles#manage", as: :article_manage
     get "/:username/:slug/edit", to: "articles#edit"
     get "/:username/:slug/delete_confirm", to: "articles#delete_confirm"
+    get "/:username/:slug/discussion_lock_confirm", to: "articles#discussion_lock_confirm"
+    get "/:username/:slug/discussion_unlock_confirm", to: "articles#discussion_unlock_confirm"
     get "/:username/:slug/stats", to: "articles#stats"
     get "/:username/:view", to: "stories#index",
                             constraints: { view: /comments|moderate|admin/ }

cypress/integration/articleFlows/manageFlows/lockDiscussion.spec.js

@@ -0,0 +1,107 @@
+describe('Lock discussion', () => {
+  const getDiscussionLockButton = () =>
+    cy.findByRole('link', {
+      name: 'Lock discussion',
+    });
+
+  const getDiscussionUnlockButton = () =>
+    cy.findByRole('link', {
+      name: 'Unlock discussion',
+    });
+
+  const getDiscussionLockSubmitButton = () =>
+    cy.findByRole('button', {
+      name: 'Lock discussion',
+    });
+
+  const exampleReason = 'Discussion lock example reason!';
+  const exampleNotes = 'Discussion lock example notes!';
+
+  describe('locking the discussion', () => {
+    beforeEach(() => {
+      cy.testSetup();
+      cy.fixture('users/articleEditorV1User.json').as('user');
+
+      cy.get('@user').then((user) => {
+        cy.loginUser(user).then(() => {
+          cy.createArticle({
+            title: 'Test Article',
+            tags: ['beginner', 'ruby', 'go'],
+            content: `This is a test article's contents.`,
+            published: true,
+          }).then((response) => {
+            cy.visit(`${response.body.current_state_path}/manage`);
+          });
+        });
+      });
+    });
+
+    it('should allow a user to lock a discussion', () => {
+      getDiscussionLockButton().click();
+
+      cy.findByRole('heading', {
+        name: 'Are you sure you want to lock the discussion on this post?',
+      }).should('exist');
+
+      getDiscussionLockSubmitButton().should('exist').click();
+      getDiscussionUnlockButton().should('exist');
+    });
+
+    it('should allow a user to supply a reason and notes', () => {
+      getDiscussionLockButton().click();
+      cy.findByRole('textbox', {
+        name: 'Reason for locking the discussion (optional) - this will be publicly displayed',
+      }).should('exist');
+
+      cy.findByRole('textbox', {
+        name: 'Notes (optional) - this is only visible to you and admins',
+      }).should('exist');
+    });
+  });
+
+  describe('when an article has its discussion locked', () => {
+    beforeEach(() => {
+      cy.testSetup();
+      cy.fixture('users/articleEditorV1User.json').as('user');
+
+      cy.get('@user').then((user) => {
+        cy.loginUser(user).then(() => {
+          cy.createArticle({
+            title: 'Test Article',
+            tags: ['beginner', 'ruby', 'go'],
+            content: `This is a test article's contents.`,
+            published: true,
+          }).then((response) => {
+            const articlePath = response.body.current_state_path;
+            cy.visit(`${articlePath}/manage`);
+            getDiscussionLockButton().click();
+            cy.get('#discussion_lock_reason')
+              .should('be.visible')
+              .type(exampleReason);
+            cy.get('#discussion_lock_notes')
+              .should('be.visible')
+              .type(exampleNotes);
+            getDiscussionLockSubmitButton().click();
+            cy.visit(articlePath);
+          });
+        });
+      });
+    });
+
+    it('should show the discussion lock reason on an article', () => {
+      cy.get('#discussion-lock').should(($discussionLock) => {
+        expect($discussionLock).to.contain.text(exampleReason);
+      });
+    });
+
+    it('should not show the discussion lock notes on an article', () => {
+      cy.get('#discussion-lock').should(($discussionLock) => {
+        expect($discussionLock).not.to.contain.text(exampleNotes);
+      });
+    });
+
+    it('should not show the new comment box', () => {
+      cy.get('#new_comment').should('not.exist');
+    });
+  });
+});

cypress/integration/articleFlows/manageFlows/unlockDiscussion.spec.js

@@ -0,0 +1,88 @@
+describe('Unlock discussion', () => {
+  const getDiscussionLockButton = () =>
+    cy.findByRole('link', {
+      name: 'Lock discussion',
+    });
+
+  const getDiscussionUnlockButton = () =>
+    cy.findByRole('link', {
+      name: 'Unlock discussion',
+    });
+
+  const getDiscussionLockSubmitButton = () =>
+    cy.findByRole('button', {
+      name: 'Lock discussion',
+    });
+
+  const getDiscussionUnlockSubmitButton = () =>
+    cy.findByRole('button', {
+      name: 'Unlock discussion',
+    });
+
+  describe('Unlocking the discussion', () => {
+    beforeEach(() => {
+      cy.testSetup();
+      cy.fixture('users/articleEditorV1User.json').as('user');
+
+      cy.get('@user').then((user) => {
+        cy.loginUser(user).then(() => {
+          cy.createArticle({
+            title: 'Test Article',
+            tags: ['beginner', 'ruby', 'go'],
+            content: `This is a test article's contents.`,
+            published: true,
+          }).then((response) => {
+            cy.visit(`${response.body.current_state_path}/manage`);
+            getDiscussionLockButton().click();
+            getDiscussionLockSubmitButton().click();
+          });
+        });
+      });
+    });
+
+    it('should allow a user to unlock a discussion', () => {
+      getDiscussionUnlockButton().click();
+      getDiscussionUnlockSubmitButton().click();
+
+      getDiscussionLockButton().should('exist');
+    });
+
+    it('should ask the user to confirm the discussion unlock', () => {
+      getDiscussionUnlockButton().click();
+
+      cy.findByRole('heading', {
+        name: 'Are you sure you want to unlock the discussion on this post?',
+      }).should('exist');
+
+      getDiscussionUnlockSubmitButton().should('exist');
+    });
+  });
+
+  describe('when an article has its discussion unlocked', () => {
+    beforeEach(() => {
+      cy.testSetup();
+      cy.fixture('users/articleEditorV1User.json').as('user');
+
+      cy.get('@user').then((user) => {
+        cy.loginUser(user).then(() => {
+          cy.createArticle({
+            title: 'Test Article',
+            tags: ['beginner', 'ruby', 'go'],
+            content: `This is a test article's contents.`,
+            published: true,
+          }).then((response) => {
+            cy.visit(response.body.current_state_path);
+          });
+        });
+      });
+    });
+
+    it('should show the new comment box', () => {
+      cy.get('#new_comment').should('exist');
+    });
+
+    it('should not show a discussion lock', () => {
+      cy.get('#dicussion-lock').should('not.exist');
+    });
+  });
+});

db/migrate/20210531152321_create_discussion_locks.rb

@@ -0,0 +1,12 @@
+class CreateDiscussionLocks < ActiveRecord::Migration[6.1]
+  def change
+    create_table :discussion_locks do |t|
+      t.references :article, null: false, foreign_key: true, index: { unique: true }
+      t.references :locking_user, references: :users, foreign_key: { to_table: :users }, null: false
+      t.text :reason
+      t.text :notes
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -461,6 +461,17 @@ ActiveRecord::Schema.define(version: 2021_06_09_103939) do
     t.index ["user_id", "token", "platform", "consumer_app_id"], name: "index_devices_on_user_id_and_token_and_platform_and_app", unique: true
   end
 
+  create_table "discussion_locks", force: :cascade do |t|
+    t.bigint "article_id", null: false
+    t.datetime "created_at", precision: 6, null: false
+    t.bigint "locking_user_id", null: false
+    t.text "notes"
+    t.text "reason"
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["article_id"], name: "index_discussion_locks_on_article_id", unique: true
+    t.index ["locking_user_id"], name: "index_discussion_locks_on_locking_user_id"
+  end
+
   create_table "display_ad_events", force: :cascade do |t|
     t.string "category"
     t.string "context_type"
@@ -1527,6 +1538,8 @@ ActiveRecord::Schema.define(version: 2021_06_09_103939) do
   add_foreign_key "custom_profile_fields", "profiles", on_delete: :cascade
   add_foreign_key "devices", "consumer_apps"
   add_foreign_key "devices", "users"
+  add_foreign_key "discussion_locks", "articles"
+  add_foreign_key "discussion_locks", "users", column: "locking_user_id"
   add_foreign_key "display_ad_events", "display_ads", on_delete: :cascade
   add_foreign_key "display_ad_events", "users", on_delete: :cascade
   add_foreign_key "display_ads", "organizations", on_delete: :cascade

spec/factories/articles.rb

@@ -61,4 +61,8 @@ FactoryBot.define do
   trait :with_user_subscription_tag_role_user do
     after(:build) { |article| article.user.add_role(:restricted_liquid_tag, LiquidTags::UserSubscriptionTag) }
   end
+
+  trait :with_discussion_lock do
+    after(:create) { |article| create(:discussion_lock, locking_user_id: article.user_id, article_id: article.id) }
+  end
 end

spec/factories/discussion_locks.rb

@@ -0,0 +1,9 @@
+FactoryBot.define do
+  factory :discussion_lock do
+    association :article, factory: :article, strategy: :create
+    association :locking_user, factory: :user, strategy: :create
+
+    reason { "This post has too many off-topic comments" }
+    notes  { "Private notes" }
+  end
+end

spec/models/article_spec.rb

@@ -18,6 +18,8 @@ RSpec.describe Article, type: :model do
     it { is_expected.to belong_to(:organization).optional }
     it { is_expected.to belong_to(:user) }
 
+    it { is_expected.to have_one(:discussion_lock).dependent(:destroy) }
+
     it { is_expected.to have_many(:comments).dependent(:nullify) }
     it { is_expected.to have_many(:mentions).dependent(:destroy) }
     it { is_expected.to have_many(:html_variant_successes).dependent(:nullify) }

spec/models/comment_spec.rb

@@ -45,6 +45,12 @@ RSpec.describe Comment, type: :model do
         expect(subject).not_to be_valid
       end
 
+      it "is invalid if commentable is an article and the discussion is locked" do
+        subject.commentable = build(:article, :with_discussion_lock)
+
+        expect(subject).not_to be_valid
+      end
+
       it "is valid without a commentable" do
         subject.commentable = nil
 

spec/models/discussion_lock_spec.rb

@@ -0,0 +1,18 @@
+require "rails_helper"
+
+RSpec.describe DiscussionLock, type: :model do
+  let(:discussion_lock) { create(:discussion_lock) }
+
+  describe "relationships" do
+    it { is_expected.to belong_to(:article) }
+    it { is_expected.to belong_to(:locking_user) }
+  end
+
+  describe "validations" do
+    subject { discussion_lock }
+
+    it { is_expected.to validate_presence_of(:article_id) }
+    it { is_expected.to validate_presence_of(:locking_user_id) }
+    it { is_expected.to validate_uniqueness_of(:article_id) }
+  end
+end

spec/models/user_spec.rb

@@ -55,6 +55,7 @@ RSpec.describe User, type: :model do
       it { is_expected.to have_many(:collections).dependent(:destroy) }
       it { is_expected.to have_many(:comments).dependent(:destroy) }
       it { is_expected.to have_many(:credits).dependent(:destroy) }
+      it { is_expected.to have_many(:discussion_locks).dependent(:destroy) }
       it { is_expected.to have_many(:display_ad_events).dependent(:destroy) }
       it { is_expected.to have_many(:email_authorizations).dependent(:delete_all) }
       it { is_expected.to have_many(:email_messages).class_name("Ahoy::Message").dependent(:destroy) }

spec/policies/discussion_lock_policy_spec.rb

@@ -0,0 +1,51 @@
+require "rails_helper"
+
+RSpec.describe DiscussionLockPolicy do
+  subject { described_class.new(locking_user, discussion_lock) }
+
+  let!(:locking_user) { create(:user) }
+  let(:article) { build_stubbed(:article, user: locking_user) }
+  let(:discussion_lock) { build_stubbed(:discussion_lock, locking_user: locking_user, article: article) }
+  let(:valid_attributes) { %i[article_id notes reason] }
+
+  context "when user is not signed-in" do
+    let(:locking_user) { nil }
+
+    it { within_block_is_expected.to raise_error(Pundit::NotAuthorizedError) }
+  end
+
+  context "when user is not the author" do
+    let(:user) { build_stubbed(:user) }
+    let(:discussion_lock) { build_stubbed(:discussion_lock, locking_user: user, article: article) }
+
+    it { is_expected.to forbid_actions(%i[create destroy]) }
+  end
+
+  context "when user is the author" do
+    let(:article) { build_stubbed(:article, user: locking_user) }
+
+    it { is_expected.to permit_actions(%i[create destroy]) }
+    it { is_expected.to permit_mass_assignment_of(valid_attributes) }
+  end
+
+  context "when user is suspended" do
+    let(:user) { build_stubbed(:user, :suspended) }
+    let(:discussion_lock) { build_stubbed(:discussion_lock, locking_user: user, article: article) }
+
+    it { is_expected.to forbid_actions(%i[create destroy]) }
+  end
+
+  context "when user is an admin" do
+    let(:locking_user) { build(:user, :admin) }
+
+    it { is_expected.to permit_actions(%i[create destroy]) }
+    it { is_expected.to permit_mass_assignment_of(valid_attributes) }
+  end
+
+  context "when user is a super_admin" do
+    let(:locking_user) { build(:user, :super_admin) }
+
+    it { is_expected.to permit_actions(%i[create destroy]) }
+    it { is_expected.to permit_mass_assignment_of(valid_attributes) }
+  end
+end

spec/requests/discussion_locks_spec.rb

@@ -0,0 +1,67 @@
+require "rails_helper"
+
+RSpec.describe "DiscussionLocks", type: :request do
+  let(:user) { create(:user) }
+  let(:cache_buster) { EdgeCache::BustArticle }
+
+  before { sign_in user }
+
+  describe "POST /discussion_locks - DiscussionLocks#create" do
+    it "creates a DiscussionLock" do
+      article = create(:article, user: user)
+      reason = "Unproductice comments."
+      notes = "Hostile comment from user @user"
+      valid_attributes = { article_id: article.id, locking_user_id: user.id, notes: notes, reason: reason }
+      expect do
+        post discussion_locks_path, params: { discussion_lock: valid_attributes }
+      end.to change(DiscussionLock, :count).by(1)
+
+      expect(request.flash[:success]).to include("Discussion was successfully locked!")
+      discussion_lock = DiscussionLock.last
+      expect(discussion_lock.article_id).to eq article.id
+      expect(discussion_lock.locking_user_id).to eq user.id
+      expect(discussion_lock.notes).to eq notes
+      expect(discussion_lock.reason).to eq reason
+    end
+
+    it "returns an error for an Article that already has a DiscussionLock" do
+      article = create(:article, :with_discussion_lock, user: user)
+      invalid_article_attributes = { article_id: article.id, locking_user_id: user.id }
+      expect do
+        post discussion_locks_path, params: { discussion_lock: invalid_article_attributes }
+      end.to change(DiscussionLock, :count).by(0)
+
+      expect(request.flash[:error]).to include("Error: Article has already been taken")
+    end
+
+    it "busts the cache for the article" do
+      article = create(:article, user: user)
+      allow(cache_buster).to receive(:call).with(article)
+      valid_attributes = { article_id: article.id, locking_user_id: user.id }
+
+      post discussion_locks_path, params: { discussion_lock: valid_attributes }
+
+      expect(cache_buster).to have_received(:call).with(article).once
+    end
+  end
+
+  describe "DELETE /discussion_locks/:id - DiscussionLocks#destroy" do
+    it "destroys a DiscussionLock" do
+      article = create(:article, user: user)
+      discussion_lock = create(:discussion_lock, article_id: article.id, locking_user_id: user.id)
+      expect do
+        delete discussion_lock_path(discussion_lock.id)
+      end.to change(DiscussionLock, :count).by(-1)
+    end
+
+    it "busts the cache for the article" do
+      article = create(:article, user: user)
+      allow(cache_buster).to receive(:call).with(article)
+      discussion_lock = create(:discussion_lock, article_id: article.id, locking_user_id: user.id)
+
+      delete discussion_lock_path(discussion_lock.id)
+
+      expect(cache_buster).to have_received(:call).with(article).once
+    end
+  end
+end

spec/system/articles/user_discussion_locks_spec.rb

@@ -0,0 +1,61 @@
+require "rails_helper"
+
+RSpec.describe "User discussion locks", type: :system, js: true do
+  let(:user) { create(:user) }
+  let(:article) { create(:article, user: user) }
+  let(:discussion_lock) { create(:discussion_lock, article: article, locking_user: user) }
+
+  before do
+    article
+    sign_in user
+  end
+
+  context "when an Article does not have a discussion lock" do
+    it "shows the discussion lock button in manage" do
+      visit dashboard_path
+      click_on "Manage"
+
+      within "div.dashboard-actions" do
+        expect(page).to have_link("Lock discussion", href: "#{article.path}/discussion_lock_confirm")
+      end
+    end
+
+    it "doesn't show a DiscussionLock on the Article" do
+      visit article.path
+      expect(page).not_to have_selector("#discussion-lock")
+    end
+
+    it "doesn't hide new comment box on the Article" do
+      visit article.path
+      expect(page).to have_selector("#new_comment")
+    end
+  end
+
+  context "when an Article has a discussion lock" do
+    before { discussion_lock }
+
+    it "shows the unlock discussion lock button in manage" do
+      visit dashboard_path
+      click_on "Manage"
+
+      within "div.dashboard-actions" do
+        expect(page).to have_link("Unlock discussion", href: "#{article.path}/discussion_unlock_confirm")
+      end
+    end
+
+    it "shows a DiscussionLock on the Article" do
+      visit article.path
+      expect(page).to have_selector("#discussion-lock")
+
+      within "#discussion-lock" do
+        expect(page).to have_text("The discussion has been locked. New comments can't be added.")
+        expect(page).to have_text(discussion_lock.reason)
+      end
+    end
+
+    it "hides new comment box on the Article" do
+      visit article.path
+      expect(page).not_to have_selector("#new_comment")
+    end
+  end
+end