Bug 161408 – [JSC] ArrowFormalParameters and MethodDefinition parameters do not use StrictFormalParameters restrictions

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: JavaScriptCore

[Caitlin Potter (:caitp)]

ArrowFormalParameters and MethodDefinition parameters should be parsed according to the StrictFormalParameters production (https://tc39.github.io/ecma262/#sec-arrow-function-definitions, https://tc39.github.io/ecma262/#prod-MethodDefinition).

Per https://tc39.github.io/ecma262/#sec-function-definitions-static-semantics-early-errors, these functions should not parse successfully when there are duplicate formal parameters.

E.g.

var f = (a, a) => 1 /* should be SyntaxError */
var O = {
  m(a, a) { return 1; } /* should be SyntaxError */
};

[Joseph Pecoraro]

This gets fixed by bug 171190! I'll update the FIXME and include the tests in that change.

*** This bug has been marked as a duplicate of bug 171190 ***