Convert to destructed refactoring not enabled in JavaScript?

<!-- 🚨 STOP 🚨 𝗦𝗧𝗢𝗣 🚨 𝑺𝑻𝑶𝑷 🚨 Half of all issues filed here are duplicates, answered in the FAQ, or not appropriate for the bug tracker. Even if you think you've found a *bug*, please read the FAQ first, especially the Common "Bugs" That Aren't Bugs section! Please help us by doing the following steps before logging an issue: * Search: https://github.com/Microsoft/TypeScript/search?type=Issues * Read the FAQ: https://github.com/Microsoft/TypeScript/wiki/FAQ Please fill in the *entire* template below. --> <!-- Please try to reproduce the issue with `typescript@next`. It may have already been fixed. --> **TypeScript Version:** 3.5.0-dev.20190404 <!-- Search terms you tried before logging this (so others can find this issue more easily) --> **Search Terms:** - refactor / refactoring - convert to destructed parameters **Code** For a simple js file ```js function doStuff(a, b, c) { return a + b + c; } doStuff('a', 'b', 1); doStuff('x', 'y', 2); ``` **Expected behavior:** A convert to restructured refactoring is available on `doStuff` **Actual behavior:** I'm not seeing any such refactoring show up in js files **Playground Link:** <!-- A link to a TypeScript Playground "Share" link which demonstrates this behavior --> **Related Issues:** <!-- Did you find other bugs that looked similar? --> - #23552