Fix: estraverse/escope to work with unknowns (fixes #5476)

lib/eslint.js

@@ -11,8 +11,7 @@
 //------------------------------------------------------------------------------
 
 var lodash = require("lodash"),
-    espree = require("espree"),
-    estraverse = require("estraverse"),
+    Traverser = require("./util/traverser"),
     escope = require("escope"),
     Environments = require("./config/environments"),
     blankScriptAST = require("../conf/blank-script.json"),
@@ -522,7 +521,7 @@ module.exports = (function() {
         scopeMap = null,
         scopeManager = null,
         currentFilename = null,
-        controller = null,
+        traverser = null,
         reportingConfig = [],
         sourceCode = null;
 
@@ -640,7 +639,7 @@ module.exports = (function() {
         currentScopes = null;
         scopeMap = null;
         scopeManager = null;
-        controller = null;
+        traverser = null;
         reportingConfig = [];
         sourceCode = null;
     };
@@ -786,7 +785,7 @@ module.exports = (function() {
 
             // save config so rules can access as necessary
             currentConfig = config;
-            controller = new estraverse.Controller();
+            traverser = new Traverser();
 
             ecmaFeatures = currentConfig.parserOptions.ecmaFeatures || {};
             ecmaVersion = currentConfig.parserOptions.ecmaVersion || 5;
@@ -798,8 +797,7 @@ module.exports = (function() {
                 impliedStrict: ecmaFeatures.impliedStrict,
                 ecmaVersion: ecmaVersion,
                 sourceType: currentConfig.parserOptions.sourceType || "script",
-                childVisitorKeys: espree.VisitorKeys,
-                fallback: "none"
+                fallback: Traverser.getKeys
             });
             currentScopes = scopeManager.scopes;
 
@@ -839,15 +837,14 @@ module.exports = (function() {
              * an event is fired. This allows any listeners to automatically be informed
              * that this type of node has been found and react accordingly.
              */
-            controller.traverse(ast, {
+            traverser.traverse(ast, {
                 enter: function(node, parent) {
                     node.parent = parent;
                     eventGenerator.enterNode(node);
                 },
                 leave: function(node) {
                     eventGenerator.leaveNode(node);
-                },
-                keys: espree.VisitorKeys
+                }
             });
         }
 
@@ -976,22 +973,22 @@ module.exports = (function() {
      * @returns {ASTNode[]} Array of objects representing ancestors.
      */
     api.getAncestors = function() {
-        return controller.parents();
+        return traverser.parents();
     };
 
     /**
      * Gets the scope for the current node.
      * @returns {Object} An object representing the current node's scope.
      */
     api.getScope = function() {
-        var parents = controller.parents(),
+        var parents = traverser.parents(),
             scope = currentScopes[0];
 
         // Don't do this for Program nodes - they have no parents
         if (parents.length) {
 
             // if current node introduces a scope, add it to the list
-            var current = controller.current();
+            var current = traverser.current();
             if (currentConfig.parserOptions.ecmaVersion >= 6) {
                 if (["BlockStatement", "SwitchStatement", "CatchClause", "FunctionDeclaration", "FunctionExpression", "ArrowFunctionExpression"].indexOf(current.type) >= 0) {
                     parents.push(current);

lib/rules/no-unmodified-loop-condition.js

@@ -12,8 +12,7 @@
 //------------------------------------------------------------------------------
 
 var Map = require("es6-map"),
-    espree = require("espree"),
-    estraverse = require("estraverse"),
+    Traverser = require("../util/traverser"),
     astUtils = require("../ast-utils");
 
 //------------------------------------------------------------------------------
@@ -116,18 +115,18 @@ var isInLoop = {
  * @returns {boolean} `true` if the node is dynamic.
  */
 function hasDynamicExpressions(root) {
-    var retv = false;
+    var retv = false,
+        traverser = new Traverser();
 
-    estraverse.traverse(root, {
+    traverser.traverse(root, {
         enter: function(node) {
             if (DYNAMIC_PATTERN.test(node.type)) {
                 retv = true;
                 this.break();
             } else if (SKIP_PATTERN.test(node.type)) {
                 this.skip();
             }
-        },
-        keys: espree.VisitorKeys
+        }
     });
 
     return retv;

lib/util/source-code.js

@@ -12,8 +12,7 @@
 
 var lodash = require("lodash"),
     createTokenStore = require("../token-store.js"),
-    espree = require("espree"),
-    estraverse = require("estraverse");
+    Traverser = require("./traverser");
 
 //------------------------------------------------------------------------------
 // Private
@@ -262,10 +261,11 @@ SourceCode.prototype = {
      * @returns {ASTNode} The node if found or null if not found.
      */
     getNodeByRangeIndex: function(index) {
-        var result = null;
-        var resultParent = null;
+        var result = null,
+            resultParent = null,
+            traverser = new Traverser();
 
-        estraverse.traverse(this.ast, {
+        traverser.traverse(this.ast, {
             enter: function(node, parent) {
                 if (node.range[0] <= index && index < node.range[1]) {
                     result = node;
@@ -278,8 +278,7 @@ SourceCode.prototype = {
                 if (node === result) {
                     this.break();
                 }
-            },
-            keys: espree.VisitorKeys
+            }
         });
 
         return result ? lodash.assign({parent: resultParent}, result) : null;

lib/util/traverser.js

@@ -0,0 +1,58 @@
+/**
+ * @fileoverview Wrapper around estraverse
+ * @author Nicholas C. Zakas
+ * @copyright 2016 Nicholas C. Zakas. All rights reserved.
+ * See LICENSE in root directory for full license.
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+var estraverse = require("estraverse");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+var KEY_BLACKLIST = [
+    "parent",
+    "leadingComments",
+    "trailingComments"
+];
+
+/**
+ * Wrapper around an estraverse controller that ensures the correct keys
+ * are visited.
+ * @constructor
+ */
+function Traverser() {
+
+    var controller = Object.create(new estraverse.Controller()),
+        originalTraverse = controller.traverse;
+
+    // intercept call to traverse() and add the fallback key to the visitor
+    controller.traverse = function(node, visitor) {
+        visitor.fallback = Traverser.getKeys;
+        return originalTraverse.call(this, node, visitor);
+    };
+
+    return controller;
+}
+
+/**
+ * Calculates the keys to use for traversal.
+ * @param {ASTNode} node The node to read keys from.
+ * @returns {string[]} An array of keys to visit on the node.
+ * @private
+ */
+Traverser.getKeys = function(node) {
+    return Object.keys(node).filter(function(key) {
+        return KEY_BLACKLIST.indexOf(key) === -1;
+    });
+};
+
+module.exports = Traverser;
+
+

package.json

@@ -41,9 +41,9 @@
     "debug": "^2.1.1",
     "doctrine": "^1.2.0",
     "es6-map": "^0.1.3",
-    "escope": "^3.5.0",
+    "escope": "^3.6.0",
     "espree": "^3.1.1",
-    "estraverse": "^4.1.1",
+    "estraverse": "^4.2.0",
     "esutils": "^2.0.2",
     "file-entry-cache": "^1.1.1",
     "glob": "^6.0.4",