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build/node_modules/hydrolysis/lib/ast-utils/feature-finder.js

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+/**
+ * @license
+ * Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
+ * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+ * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+ * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+ * Code distributed by Google as part of the polymer project is also
+ * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+ */
+// jshint node: true
+'use strict';
+var estraverse = require('estraverse');
+
+var esutil = require('./esutil');
+
+var numFeatures = 0;
+
+module.exports = function featureFinder() {
+  /** @type {!Array<FeatureDescriptor>} The features we've found. */
+  var features = [];
+
+  var visitors = {
+
+    enterCallExpression: function enterCallExpression(node, parent) {
+      if (!esutil.matchesCallExpression(node.callee, ['Polymer', 'Base', '_addFeature'])) {
+        return;
+      }
+      /** @type {!FeatureDescriptor} */
+      var feature = {};
+      this._extractDesc(feature, node, parent);
+      this._extractProperties(feature, node, parent);
+
+      features.push(feature);
+    },
+
+    _extractDesc: function _extractDesc(feature, node, parent) {
+      feature.desc = esutil.getAttachedComment(parent);
+    },
+
+    _extractProperties: function _extractProperties(feature, node, parent) {
+      var featureNode = node.arguments[0];
+      if (featureNode.type !== 'ObjectExpression') {
+        console.warn(
+            'Expected first argument to Polymer.Base._addFeature to be an object.',
+            'Got', featureNode.type, 'instead.');
+        return;
+      }
+      if (!featureNode.properties) return;
+
+      feature.properties = featureNode.properties.map(esutil.toPropertyDescriptor);
+    },
+
+  };
+
+  return {visitors: visitors, features: features};
+};