1 files changed, 69 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/no-catch-shadow.js b/tools/node_modules/eslint/lib/rules/no-catch-shadow.js
new file mode 100644
index 0000000000..bef61902e9
--- /dev/null
+++ b/tools/node_modules/eslint/lib/rules/no-catch-shadow.js
@@ -0,0 +1,69 @@
+/**
+ * @fileoverview Rule to flag variable leak in CatchClauses in IE 8 and earlier
+ * @author Ian Christian Myers
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("../ast-utils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "disallow `catch` clause parameters from shadowing variables in the outer scope",
+            category: "Variables",
+            recommended: false
+        },
+
+        schema: []
+    },
+
+    create(context) {
+
+        //--------------------------------------------------------------------------
+        // Helpers
+        //--------------------------------------------------------------------------
+
+        /**
+         * Check if the parameters are been shadowed
+         * @param {Object} scope current scope
+         * @param {string} name parameter name
+         * @returns {boolean} True is its been shadowed
+         */
+        function paramIsShadowing(scope, name) {
+            return astUtils.getVariableByName(scope, name) !== null;
+        }
+
+        //--------------------------------------------------------------------------
+        // Public API
+        //--------------------------------------------------------------------------
+
+        return {
+
+            CatchClause(node) {
+                let scope = context.getScope();
+
+                /*
+                 * When ecmaVersion >= 6, CatchClause creates its own scope
+                 * so start from one upper scope to exclude the current node
+                 */
+                if (scope.block === node) {
+                    scope = scope.upper;
+                }
+
+                if (paramIsShadowing(scope, node.param.name)) {
+                    context.report({ node, message: "Value of '{{name}}' may be overwritten in IE 8 and earlier.", data: { name: node.param.name } });
+                }
+            }
+        };
+
+    }
+};