1 files changed, 69 insertions, 0 deletions
diff --git a/node_modules/espurify/lib/clone-ast.js b/node_modules/espurify/lib/clone-ast.js
new file mode 100644
index 000000000..f748b885d
--- /dev/null
+++ b/node_modules/espurify/lib/clone-ast.js
@@ -0,0 +1,69 @@
+'use strict';
+
+var isArray = require('core-js/library/fn/array/is-array');
+var objectKeys = require('core-js/library/fn/object/keys');
+var indexOf = require('core-js/library/fn/array/index-of');
+var reduce = require('core-js/library/fn/array/reduce');
+
+module.exports = function cloneWithWhitelist (astWhiteList) {
+    var whitelist = reduce(objectKeys(astWhiteList), function (props, key) {
+        var propNames = astWhiteList[key];
+        var prepend = (indexOf(propNames, 'type') === -1) ? ['type'] : [];
+        props[key] = prepend.concat(propNames);
+        return props;
+    }, {});
+
+    function cloneNodeOrObject (obj) {
+        var props = obj.type ? whitelist[obj.type] : null;
+        if (props) {
+            return cloneNode(obj, props);
+        } else {
+            return cloneObject(obj);
+        }
+    }
+
+    function cloneArray (ary) {
+        var i = ary.length, clone = [];
+        while (i--) {
+            clone[i] = cloneOf(ary[i]);
+        }
+        return clone;
+    }
+
+    function cloneNode (node, props) {
+        var i, len, key, clone = {};
+        for (i = 0, len = props.length; i < len; i += 1) {
+            key = props[i];
+            if (node.hasOwnProperty(key)) {
+                clone[key] = cloneOf(node[key]);
+            }
+        }
+        return clone;
+    }
+
+    function cloneObject (obj) {
+        var props = objectKeys(obj);
+        var i, len, key, clone = {};
+        for (i = 0, len = props.length; i < len; i += 1) {
+            key = props[i];
+            clone[key] = cloneOf(obj[key]);
+        }
+        return clone;
+    }
+
+    function cloneOf (val) {
+        if (typeof val === 'object' && val !== null) {
+            if (val instanceof RegExp) {
+                return new RegExp(val);
+            } else if (isArray(val)) {
+                return cloneArray(val);
+            } else {
+                return cloneNodeOrObject(val);
+            }
+        } else {
+            return val;
+        }
+    }
+
+    return cloneNodeOrObject;
+};