first commit

web/core/scripts/css/compile.js

@@ -0,0 +1,40 @@
+const chalk = require('chalk');
+const log = require('./log');
+const fs = require('fs');
+const postcss = require('postcss');
+const postcssCustomProperties = require('postcss-custom-properties');
+const postcssCalc = require("postcss-calc");
+const postcssImport = require('postcss-import');
+const autoprefixer = require('autoprefixer');
+const postcssHeader = require('postcss-header');
+
+module.exports = (filePath, callback) => {
+  // Transform the file.
+  fs.readFile(filePath, (err, css) => {
+    postcss([
+      postcssImport(),
+      postcssCustomProperties({
+        // Remove converted properties from the generated code. This needs to be
+        // set to ensure that CSS minifiers don't remove the generated values.
+        preserve: false,
+      }),
+      postcssCalc,
+      autoprefixer({
+        // Output without visual cascade for more consistency with existing
+        // Drupal CSS.
+        cascade: false
+      }),
+      postcssHeader({
+        header: `/*\n * DO NOT EDIT THIS FILE.\n * See the following change record for more information,\n * https://www.drupal.org/node/2815083\n * @preserve\n */\n`,
+      }),
+    ])
+    .process(css, { from: filePath })
+    .then(result => {
+      callback(result.css);
+    })
+    .catch(error => {
+      log(chalk.red(error));
+      process.exitCode = 1;
+    });
+  });
+};