Support TypeScript 4.1 via typescript-estree

[sosukesuzuki]

Partial of #9234

This PR tries the approach @thorn0 suggested (27e7b46)

• I’ve added tests to confirm my change works.
• (If the change is user-facing) I’ve added my changes to changelog_unreleased/*/pr-XXXX.md file following changelog_unreleased/TEMPLATE.md.
• I’ve read the contributing guidelines.

✨Try the playground for this PR✨

[sosukesuzuki]

I don't know why, but this change removes the TypeScript typecheck error. Why...?

[fisker]

Maybe #9207

[sosukesuzuki]

All prod tests are failed. I'm looking into that.

[fisker]

Seems we can access decorators via services

require("@typescript-eslint/typescript-estree").parseAndGenerateServices('@foo\nfunction bar(){}').services.program.getSourceFile().statements[0]

[fisker]

I'm going to take a shot

[fisker]

@typescript-eslint/typescript-estree@4.8.0 released, working on it.

[fisker]

@bradzacher Did I do something wrong? There is no info in esTreeNodeToTSNodeMap

> const {ast, esTreeNodeToTSNodeMap} = require("@typescript-eslint/typescript-estree").parseWithNodeMaps('@foo()\nfunction bar(){}')
undefined
> esTreeNodeToTSNodeMap.get(ast.body[0])
undefined

> const {ast, services:{esTreeNodeToTSNodeMap}} = require("@typescript-eslint/typescript-estree").parseAndGenerateServices('@foo()\nfunction bar(){}')
undefined
> esTreeNodeToTSNodeMap.get(ast.body[0])
<ref *1> NodeObject {
  pos: 0,
  end: 23,
  flags: 0,
  modifierFlagsCache: 0,
  transformFlags: 1050625,
  parent: <ref *2> SourceFileObject
//...

[bradzacher]

FFS I'm a stooge.
https://github.com/typescript-eslint/typescript-eslint/blob/master/packages/typescript-estree/src/parser.ts#L383

The false here means "don't calculate maps".
I can't believe I didn't think about that!
My test just asserted the maps existed, not that they contained anything.
🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦🤦

I'll have a fix released ASAP.

[bradzacher]

typescript-eslint/typescript-eslint#2773 is merged, but I can't do an NPM release right now as azure pipelines have an outage....
Yeah we need to move it to GH actions. Will ping back when it's released.

For now you can test against
https://www.npmjs.com/package/@typescript-eslint/typescript-estree/v/4.8.1-alpha.1
Which releases via GH actions.

[sosukesuzuki]

Can we merge this as is? or should wait 4.8.1?

[fisker]

I don't think we need wait for @typescript-eslint/typescript-estree , but do we need wait for typescript release stable version?

[sosukesuzuki]

TypeScript 4.1 will seem be released soon according to microsoft/TypeScript#40124. Let's wait.

[bradzacher]

4.8.1 is live with the fix :)

[fisker]

Hey all, we're going to retarget to Thursday (11/19) just to ensure that everything is working as optimally as possible and documented.

microsoft/TypeScript#40124 (comment)

[sosukesuzuki]

I see. let's merge this PR for now. I'll do the other work required for the release.

When TypeScript 4.1 is released, I'll create a PR just to update it.