Website Structure

Frontend-Learner/node_modules/postcss-reduce-initial/src/index.js

@@ -0,0 +1,80 @@
+'use strict';
+const { dirname } = require('path');
+const browserslist = require('browserslist');
+const { isSupported } = require('caniuse-api');
+const fromInitial = require('./data/fromInitial.json');
+const toInitial = require('./data/toInitial.json');
+const ignoreProps = require('./lib/ignoreProps.js');
+
+const initial = 'initial';
+
+// In most of the browser including chrome the initial for `writing-mode` is not `horizontal-tb`. Ref https://github.com/cssnano/cssnano/pull/905
+const defaultIgnoreProps = ignoreProps;
+
+/**
+ * @typedef {{ overrideBrowserslist?: string | string[] }} AutoprefixerOptions
+ * @typedef {Pick<browserslist.Options, 'stats' | 'path' | 'env'>} BrowserslistOptions
+ * @typedef {{ignore?: string[]} & AutoprefixerOptions & BrowserslistOptions} Options
+ */
+
+/**
+ * @type {import('postcss').PluginCreator<Options>}
+ * @param {Options} options
+ * @return {import('postcss').Plugin}
+ */
+function pluginCreator(options = {}) {
+  return {
+    postcssPlugin: 'postcss-reduce-initial',
+
+    /**
+     * @param {import('postcss').Result & {opts: BrowserslistOptions & {file?: string}}} result
+     */
+    prepare(result) {
+      const { stats, env, from, file } = result.opts || {};
+      const browsers = browserslist(options.overrideBrowserslist, {
+        stats: options.stats || stats,
+        path: options.path || dirname(from || file || __filename),
+        env: options.env || env,
+      });
+
+      const initialSupport = isSupported('css-initial-value', browsers);
+      return {
+        OnceExit(css) {
+          css.walkDecls((decl) => {
+            const lowerCasedProp = decl.prop.toLowerCase();
+            const ignoreProp = new Set(
+              defaultIgnoreProps.concat(options.ignore || [])
+            );
+
+            if (ignoreProp.has(lowerCasedProp)) {
+              return;
+            }
+
+            if (
+              initialSupport &&
+              Object.prototype.hasOwnProperty.call(toInitial, lowerCasedProp) &&
+              decl.value.toLowerCase() ===
+                toInitial[/** @type {keyof toInitial} */ (lowerCasedProp)]
+            ) {
+              decl.value = initial;
+              return;
+            }
+
+            if (
+              decl.value.toLowerCase() !== initial ||
+              !fromInitial[/** @type {keyof fromInitial} */ (lowerCasedProp)]
+            ) {
+              return;
+            }
+
+            decl.value =
+              fromInitial[/** @type {keyof fromInitial} */ (lowerCasedProp)];
+          });
+        },
+      };
+    },
+  };
+}
+
+pluginCreator.postcss = true;
+module.exports = pluginCreator;