rel #23: disallow eval and arguments as CatchClause param

Author: michaelficarra

README.md

@@ -55,6 +55,7 @@ This is a list of all esvalid validity tests other than `null` tests and type ch
 
 * BreakStatement must have an IterationStatement or SwitchStatement as an ancestor
 * labelled BreakStatement must have a matching LabeledStatement ancestor
+* CatchClause `param` member must not be `eval` or `arguments` in strict mode
 * ContinueStatement must have an IterationStatement as an ancestor
 * labelled ContinueStatement must have a matching LabeledStatement ancestor
 * FunctionDeclaration `id` member must not be `eval` or `arguments` in strict mode

index.js

@@ -204,6 +204,8 @@ function errorsP(state) {
       case "CatchClause":
         if (!isExpression(node.param))
           errors.push(new E(node, "CatchClause `param` member must be an expression node"));
+        else if (state.strict && node.param.type === "Identifier" && esutils.keyword.isRestrictedWord(node.param.name))
+          errors.push(new E(node, "CatchClause `param` member must not be `eval` or `arguments` in strict mode"));
         if (node.body == null || node.body.type !== "BlockStatement")
           errors.push(new E(node, "CatchClause `body` member must be a BlockStatement node"));
         if (node.param != null)

test/strict.js

@@ -27,6 +27,14 @@ suite("strict mode", function() {
     validExpr(FE(exprStmt({type: "Literal", value: "use strict"})));
   });
 
+  test("CatchClause param must not be restricted in strict mode", function() {
+    validStmt({type: "TryStatement", block: BLOCK, handler: {type: "CatchClause", param: {type: "Identifier", name: "eval"}, body: BLOCK}});
+    validStmt({type: "TryStatement", block: BLOCK, handler: {type: "CatchClause", param: {type: "Identifier", name: "arguments"}, body: BLOCK}});
+    validExpr(strictFE({type: "TryStatement", block: BLOCK, handler: {type: "CatchClause", param: {type: "Identifier", name: "x"}, body: BLOCK}}));
+    invalidExpr(1, strictFE({type: "TryStatement", block: BLOCK, handler: {type: "CatchClause", param: {type: "Identifier", name: "eval"}, body: BLOCK}}));
+    invalidExpr(1, strictFE({type: "TryStatement", block: BLOCK, handler: {type: "CatchClause", param: {type: "Identifier", name: "arguments"}, body: BLOCK}}));
+  });
+
   test("Function names must not be restricted in strict mode", function() {
     validExpr(strictFE(exprStmt({type: "FunctionExpression", id: null, params: [], body: BLOCK})));
     validExpr({type: "FunctionExpression", id: {type: "Identifier", name: "eval"}, params: [], body: BLOCK});