All CLA requirements met.

You probably have to update baselines.

If we do this, the first thing you'll see every time you request completions on a string is a bunch of crossed-out properties. @sandersn any idea how easy it would be to give them a lower sort order based on JSDoc tags? Ideally, we never would've shown these properties anyway, but we traditionally had to have them there because ES6.

@deprecated has its own NodeFlags entry right now, so you just have to use the rules from the checker to decide if the signature as a whole should be considered deprecated (basically, whether all the signature's declarations are deprecated). I don't know the sort order code but I assume it would be easy.

The TypeScript team hasn't accepted the linked issue #43709. If you can get it accepted, this PR will have a better chance of being reviewed.

If we do this, the first thing you'll see every time you request completions on a string is a bunch of crossed-out properties.

A quick grep of the baselines for "big" doesn't look like there's a test for this, so you should add one, something like

/// <reference path='fourslash.ts' />
//// var s = "foo"./*1*/
verify.baselineCompletions()

Which should make it obvious what order "big" et al have.

I think before this goes in, we need to add the sorting logic first. I'd like to discuss that at an upcoming editor sync with @mjbvz and others first.

#43796 tracks that.

CC @bterlson

@sandersn verify.baselineCompletions method is broken. Your code emits baseline as a global completion such that

[
  {
    "marker": {
      "fileName": "/tests/cases/fourslash/completionsStringMethods.ts",
      "position": 6,
      "name": ""
    },
    "completionList": {
      "isGlobalCompletion": true,
      "isMemberCompletion": false,
      "isNewIdentifierLocation": false,
      "entries": [
        {
          "name": "globalThis",
          "kind": "module",
          "kindModifiers": "",
          "sortText": "5"
        },
        {
          "name": "eval",
          "kind": "function",
          "kindModifiers": "declare",
          "sortText": "5"
        },
        // ...,
      ]
    }
  }
}

I also found the following broken test.

I'm a fan of this, and I think the sorting would make it shine 👍🏻

Sorting PR: #43880

Blocked by #45615

I found that RegExp.$1 to RegExp.$9 should also be deprecated.

This pull request can be reviewed. Thank you for your time.