0.2.0 - Mid migration

web/node_modules/postcss-discard-overridden/dist/index.js

@@ -0,0 +1,57 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+
+var _postcss = require('postcss');
+
+var _postcss2 = _interopRequireDefault(_postcss);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+const OVERRIDABLE_RULES = ['keyframes', 'counter-style'];
+const SCOPE_RULES = ['media', 'supports'];
+
+function isOverridable(name) {
+    return ~OVERRIDABLE_RULES.indexOf(_postcss2.default.vendor.unprefixed(name.toLowerCase()));
+}
+
+function isScope(name) {
+    return ~SCOPE_RULES.indexOf(_postcss2.default.vendor.unprefixed(name.toLowerCase()));
+}
+
+function getScope(node) {
+    let current = node.parent;
+    const chain = [node.name.toLowerCase(), node.params];
+    do {
+        if (current.type === 'atrule' && isScope(current.name)) {
+            chain.unshift(current.name + ' ' + current.params);
+        }
+        current = current.parent;
+    } while (current);
+    return chain.join('|');
+}
+
+exports.default = _postcss2.default.plugin('postcss-discard-overridden', () => {
+    return css => {
+        const cache = {};
+        const rules = [];
+        css.walkAtRules(node => {
+            if (isOverridable(node.name)) {
+                const scope = getScope(node);
+                cache[scope] = node;
+                rules.push({
+                    node,
+                    scope
+                });
+            }
+        });
+        rules.forEach(rule => {
+            if (cache[rule.scope] !== rule.node) {
+                rule.node.remove();
+            }
+        });
+    };
+});
+module.exports = exports['default'];