String literal rename support

[Kingwl]

Fixes #5602

[Kingwl]

@typescript-bot pack this.

[typescript-bot]

Heya @Kingwl, I've started to run the tarball bundle task on this PR at 801edb2. You can monitor the build here.

[typescript-bot]

Hey @Kingwl, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/78044/artifacts?artifactName=tgz&fileId=295685A5BF3AAA029459E0812C1B6ADAFB9F02FCB950BC2A88A0BB0B0D902BA302&fileName=/typescript-4.0.0-insiders.20200628.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build.

[Kingwl]

@typescript-bot test this.

[typescript-bot]

Heya @Kingwl, I've started to run the extended test suite on this PR at 5a937eb. You can monitor the build here.

[Kingwl]

UP 👆

[andrewbranch]

@Kingwl have you checked out what happened with the tests? If you can fix those soon, I think we can get this in before 4.1 beta.

[Kingwl]

Sorry for the delay. I'm on vacation this weekend.
Hope nothing missed。

[andrewbranch]

Thanks @Kingwl! Since this is really a feature and we’re past the 4.1 beta, I think we’re going to hold it for 4.2. I’ll come back to merge as soon as we cut the release branch.

[codart1]

Suggested change

	f.f = 'foo'
	f.f = 'foo'

add new line

[aspirisen]

Hi, is it known issue that in such cases renaming doesn't work

type Actions = { type: 'one', payload: number } | { type: 'two', payload: boolean }
const q: Actions = { type: 'one', payload: 1 }

Checked on ts=4.2.0-dev.20201109
Playground

[Kingwl]

Well. Even the current implement has many limitation. But I don't think That is expected.

Could you create an issue to track that please?
I'm also happy do it that if you are not interested at it.

[wclr]

@Kingwl
Oh, this will be really great when the common case for redux/ect actions will be supported.