Intermittent type errors when opening or editing files with typescript 3.7

[KaelWD]

• VSCode Version: 1.40.0 (and 1.39.2)
• OS Version: Kubuntu 18.04

Steps to Reproduce:

1. git clone -b refactor/ts37 https://github.com/vuetifyjs/vuetify.git, run yarn && yarn build, then open it in vscode
2. Open VTreeView.ts and VtreeViewNode.ts
3. Reload the window, wait for the language server to start then switch to the other open file
4. When the errors appear, make a small edit, save the file, then undo it

Video demonstrating the problem
And anotha one

This doesn't seem to occur with ts 3.5 (master branch)

Does this issue occur when all extensions are disabled?: Yes

[mjbvz]

Confirmed with TS 3.8.0-dev.20191105. Does not depend on VS Code version and does not happen with TS 3.6.3

Specific errors are things like:

Property 'search' does not exist on type 'CombinedVueInstance<{ register?: undefined; unregister?: undefined; } & Record<never, any> & Vue & { register: null; unregister: null; } & { themeableProvide: { isDark: boolean; }; } & { appIsDark: boolean; isDark: boolean; themeClasses: object; rootIsDark: boolean; rootThemeClasses: Record<...>; } & { ...; } & Them...'

[AnyhowStep]

Is this a composite project?

If so, try,
#32028 (comment)

I'm on mobile, so I can't watch the videos.

It's been my experience that the feature in that PR can cause funky type-related errors.

Just looked at that branch from mobile. Doesn't look like a composite project

---

Does it build successfully with tsc despite errors from tsserver?

It may be tangentially related to,
#32573

#29511

Particularly,

I'm experiencing a problem that I can only think is because TS is "giving up" on resolving the type in the IDE. But it resolves the type correctly during compile time.

I've found that tsserver and tsc can have different ideas of what is valid and what is invalid

Sometimes, an upstream type incorrectly resolving to any can cause weird errors to downstream types.

I see Record<never, any> in @mjbvz 's comment, and it looks very suspicious, like an intermittent max depth error in disguise

[AnyhowStep]

Okay, I feel like this is probably the most relevant issue,
#33067

In that issue, types keep flipping between resolving correctly and resolving to any. The type resolving to Record<never, any> & T looks like that problem

[KaelWD]

Yep, it works fine when you build it. Those related issues look a lot like this other problem I had a while ago, where recursive types worked in vscode but were never in tsc: #23897 (comment)

[sheetalkamat]

Duplicate of #23897 where in order of resolution changes the result

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.