--- /dev/null
+/**
+ * @fileoverview Rule to flag variable leak in CatchClauses in IE 8 and earlier
+ * @author Ian Christian Myers
+ * @deprecated in ESLint v5.1.0
+ */
+
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("./utils/ast-utils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+ meta: {
+ type: "suggestion",
+
+ docs: {
+ description: "disallow `catch` clause parameters from shadowing variables in the outer scope",
+ category: "Variables",
+ recommended: false,
+ url: "https://eslint.org/docs/rules/no-catch-shadow"
+ },
+
+ replacedBy: ["no-shadow"],
+
+ deprecated: true,
+ schema: [],
+
+ messages: {
+ mutable: "Value of '{{name}}' may be overwritten in IE 8 and earlier."
+ }
+ },
+
+ 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[param!=null]"(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, messageId: "mutable", data: { name: node.param.name } });
+ }
+ }
+ };
+
+ }
+};