Assignment operator is definite assignment

[Kingwl]

Fixes #39088

[Kingwl]

@aminpaks Fix available here.

[Kingwl]

@typescript-bot pack this.

[typescript-bot]

Heya @Kingwl, I've started to run the tarball bundle task on this PR at fdf8d26. You can monitor the build here.

[Kingwl]

Ci is broken, but not my fault.

[orta]

@typescript-bot pack this

[typescript-bot]

Heya @orta, I've started to run the tarball bundle task on this PR at 56e134a. You can monitor the build here.

[DanielRosenwasser]

What exactly is the difference? Does a definite assignment widen to the base primitive type?

[Kingwl]

What exactly is the difference? Does a definite assignment widen to the base primitive type?

Basically yes.

[typescript-bot]

Hey @orta, 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/76651/artifacts?artifactName=tgz&fileId=5E1BAC44463C97C5571055CEDF41DB1432950FFAC33ED05242F977BB210D224A02&fileName=/typescript-4.0.0-insiders.20200616.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build.

[orta]

Confirmed the fix in the playground, looks good to me 👍