Fix yarn postcss (#18711)

* Remove postcss-cssnext

* Remove redundant code

* Update postcss-preset-env

* Account for fingerprinting

.github/workflows/ci-cd.yml

@@ -128,6 +128,8 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           bundler-cache: true
+      - run: bundle exec rails assets:precompile
+      - run: yarn run postcss
       - run: bin/test-console-check
 
   Cypress:

.postcssrc.yml

@@ -1,3 +0,0 @@
-plugins:
-  postcss-smart-import: {}
-  postcss-cssnext: {}

package.json

@@ -24,7 +24,7 @@
     "lint:frontend": "eslint 'app/assets/javascripts/**/*.js' 'app/javascript/**/*.jsx' 'app/javascript/**/*.js' 'cypress/**/*.js'",
     "test": "jest app/javascript/ bin/ --coverage",
     "test:watch": "jest app/javascript/ bin/ --watch",
-    "postcss": "postcss public/assets/*.css -d public/assets 2> postcss_error.log",
+    "postcss": "postcss public/assets/*.css -d public/assets",
     "e2e": "bin/e2e",
     "e2e:creator-onboarding-seed": "yarn run e2e --creator-onboarding-seed"
   },
@@ -132,8 +132,8 @@
     "moment": "^2.29.4",
     "postcss": "^8.4.18",
     "postcss-cli": "^10.0.0",
-    "postcss-cssnext": "^3.1.0",
+    "postcss-import": "^15.0.0",
-    "postcss-smart-import": "^0.7.6",
+    "postcss-preset-env": "^7.8.2",
     "postscribe": "^2.0.8",
     "preact": "^10.11.2",
     "prop-types": "^15.8.1",

postcss.config.js

@@ -1,12 +1,18 @@
 /* globals module, require */
 module.exports = {
   plugins: [
-    require('postcss-import'),
+    require('postcss-import')({
+      resolve: function(id, basedir) {
+        if (id.startsWith('/assets/react-dates/')) {
+          return require('path').resolve(process.cwd(), "node_modules/react-dates/lib/css/_datepicker.css");
+        } else {
+          return require('path').resolve(basedir, id);
+        }
+      }
+    }),
     require('postcss-flexbugs-fixes'),
     require('postcss-preset-env')({
-      autoprefixer: {
+      autoprefixer: { flexbox: 'no-2009' },
-        flexbox: 'no-2009',
-      },
       stage: 3,
     }),
   ],