VS Code codebase compile errors with 3.9.0-dev.20200324

[mjbvz]

TypeScript Version: 3.9.0-dev.20200324

Repro

1. Try using 3.9.0-dev.20200324 to build VS Code

Problem
I see ~30 errors (after fixing a few simple ones). Many of these are related to awaited. I'll start splitting out individual issues when I can create small repos

[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/services/search/node/rawSearchService.ts(382,3): Type '(Anonymous class)' is not assignable to type 'CancelablePromise<C>'.
  Types of property 'then' are incompatible.
    Type '<TResult1 = C, TResult2 = never>(resolve?: ((value: C) => TResult1 | Promise<TResult1>) | null | undefined, reject?: ((reason: any) => TResult2 | Promise<TResult2>) | null | undefined) => Promise<...>' is not assignable to type '<TResult1 = C, TResult2 = never>(onfulfilled?: ((value: awaited C) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => Promise<...>'.
      Types of parameters 'resolve' and 'onfulfilled' are incompatible.
        Types of parameters 'value' and 'value' are incompatible.
          Type 'C' is not assignable to type 'awaited C'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/services/search/node/rawSearchService.ts(387,4): Property 'then' in type '(Anonymous class)' is not assignable to the same property in base type 'CancelablePromise<C>'.
  Type '<TResult1 = C, TResult2 = never>(resolve?: ((value: C) => TResult1 | Promise<TResult1>) | null | undefined, reject?: ((reason: any) => TResult2 | Promise<TResult2>) | null | undefined) => Promise<...>' is not assignable to type '<TResult1 = C, TResult2 = never>(onfulfilled?: ((value: awaited C) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => Promise<...>'.
    Types of parameters 'resolve' and 'onfulfilled' are incompatible.
      Types of parameters 'value' and 'value' are incompatible.
        Type 'C' is not assignable to type 'awaited C'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/services/search/node/rawSearchService.ts(388,25): Argument of type '((value: C) => TResult1 | Promise<TResult1>) | null | undefined' is not assignable to parameter of type '((value: awaited C) => TResult1 | awaited TResult1 | PromiseLike<TResult1 | awaited TResult1>) | null | undefined'.
  Type '(value: C) => TResult1 | Promise<TResult1>' is not assignable to type '(value: awaited C) => TResult1 | awaited TResult1 | PromiseLike<TResult1 | awaited TResult1>'.
    Types of parameters 'value' and 'value' are incompatible.
      Type 'awaited C' is not assignable to type 'C'.
        'C' could be instantiated with an arbitrary type which could be unrelated to 'awaited C'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/services/history/browser/history.ts(342,49): Argument of type '() => boolean' is not assignable to parameter of type '() => void | PromiseLike<void>'.
  Type 'boolean' is not assignable to type 'void | PromiseLike<void>'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/contrib/search/common/searchModel.ts(609,21): Type 'FileMatch | FileMatch[]' must have a '[Symbol.iterator]()' method that returns an iterator.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/base/browser/ui/list/listPaging.ts(58,53): Argument of type 'awaited TElement' is not assignable to parameter of type 'TElement'.
  'TElement' could be instantiated with an arbitrary type which could be unrelated to 'awaited TElement'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/platform/extensionManagement/node/extensionManagementService.ts(89,42): Type '{ [x: string]: any; }' must have a '[Symbol.iterator]()' method that returns an iterator.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/api/common/extHostTreeViews.ts(336,43): Argument of type 'awaited T' is not assignable to parameter of type 'T'.
  'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/api/common/extHostTreeViews.ts(337,43): Argument of type 'awaited T' is not assignable to parameter of type 'T'.
  'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/api/common/extHostCommands.ts(230,67): Argument of type '<R>(...args: any[]) => Promise<R>' is not assignable to parameter of type '<T>(...args: any[]) => T | Thenable<T>'.
  Type 'Promise<T>' is not assignable to type 'T | Thenable<T>'.
    Type 'Promise<T>' is not assignable to type 'Thenable<T>'.
      Types of property 'then' are incompatible.
        Type '<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: awaited T) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => Promise<...>' is not assignable to type '{ <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<TResult>) | undefined, onrejected?: ((reason: any) => TResult | Thenable<TResult>) | undefined): Thenable<...>; <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<...>) | undefined, onrejected?: ((reason: any) => void) | undefined): Thenable<...>; <T...'.
          Types of parameters 'onfulfilled' and 'onfulfilled' are incompatible.
            Type '((value: T) => any) | undefined' is not assignable to type '((value: awaited T) => any) | null | undefined'.
              Type '(value: T) => any' is not assignable to type '(value: awaited T) => any'.
                Types of parameters 'value' and 'value' are incompatible.
                  Type 'awaited T' is not assignable to type 'T'.
                    'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/api/common/extHost.api.impl.ts(246,5): Type 'Promise<T>' is not assignable to type 'Thenable<T>'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/api/common/extHost.api.impl.ts(1076,3): Type 'Promise<awaited T>' is not assignable to type 'Thenable<T>'.
  Types of property 'then' are incompatible.
    Type '<TResult1 = awaited T, TResult2 = never>(onfulfilled?: ((value: awaited T) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => Promise<...>' is not assignable to type '{ <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<TResult>) | undefined, onrejected?: ((reason: any) => TResult | Thenable<TResult>) | undefined): Thenable<...>; <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<...>) | undefined, onrejected?: ((reason: any) => void) | undefined): Thenable<...>; <T...'.
      Types of parameters 'onfulfilled' and 'onfulfilled' are incompatible.
        Type '((value: T) => any) | undefined' is not assignable to type '((value: awaited T) => any) | null | undefined'.
          Type '(value: T) => any' is not assignable to type '(value: awaited T) => any'.
            Types of parameters 'value' and 'value' are incompatible.
              Type 'awaited T' is not assignable to type 'T'.
                'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/editor/contrib/hover/hoverOperation.ts(104,39): Argument of type '(asyncResult: Result) => void' is not assignable to parameter of type '(value: awaited Result) => void | PromiseLike<void>'.
  Types of parameters 'asyncResult' and 'value' are incompatible.
    Type 'awaited Result' is not assignable to type 'Result'.
      'Result' could be instantiated with an arbitrary type which could be unrelated to 'awaited Result'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/base/common/async.ts(37,9): Conversion of type '(Anonymous class)' to type 'CancelablePromise<T>' may be a mistake because neither type sufficiently overlaps with the other. If this was intentional, convert the expression to 'unknown' first.
  Property '[Symbol.toStringTag]' is missing in type '(Anonymous class)' but required in type 'CancelablePromise<T>'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/base/common/async.ts(42,24): Argument of type '((value: T) => TResult1 | Promise<TResult1>) | null | undefined' is not assignable to parameter of type '((value: awaited T) => TResult1 | awaited TResult1 | PromiseLike<TResult1 | awaited TResult1>) | null | undefined'.
  Type '(value: T) => TResult1 | Promise<TResult1>' is not assignable to type '(value: awaited T) => TResult1 | awaited TResult1 | PromiseLike<TResult1 | awaited TResult1>'.
    Types of parameters 'value' and 'value' are incompatible.
      Type 'awaited T' is not assignable to type 'T'.
        'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/base/common/async.ts(79,12): Argument of type 'T | Thenable<T>' is not assignable to parameter of type 'T | awaited T | PromiseLike<T> | undefined'.
  Type 'Thenable<T>' is not assignable to type 'T | awaited T | PromiseLike<T> | undefined'.
    Type 'Thenable<T>' is not assignable to type 'PromiseLike<T>'.
      Types of property 'then' are incompatible.
        Type '{ <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<TResult>) | undefined, onrejected?: ((reason: any) => TResult | Thenable<TResult>) | undefined): Thenable<...>; <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<...>) | undefined, onrejected?: ((reason: any) => void) | undefined): Thenable<...>; <T...' is not assignable to type '<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: awaited T) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => PromiseLike<...>'.
          Types of parameters 'onfulfilled' and 'onfulfilled' are incompatible.
            Type '((value: awaited T) => any) | null | undefined' is not assignable to type '((value: T) => any) | undefined'.
              Type 'null' is not assignable to type '((value: T) => any) | undefined'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/base/common/async.ts(403,19): Argument of type 'awaited T' is not assignable to parameter of type 'T'.
  'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/base/common/async.ts(463,17): Argument of type '(value?: T | Promise<T> | undefined) => void' is not assignable to parameter of type '(value: awaited T) => void | PromiseLike<void>'.
  Types of parameters 'value' and 'value' are incompatible.
    Type 'awaited T' is not assignable to type 'T | Promise<T> | undefined'.
      Type 'awaited T' is not assignable to type 'Promise<T>'.
[14:16:40] Error: /Users/matb/projects/vscode/src/vs/workbench/workbench.web.api.ts(249,25): Type 'readonly ICommand[] | undefined' must have a '[Symbol.iterator]()' method that returns an iterator.
[14:16:40] Error: /Users/matb/projects/vscode/extensions/merge-conflict/src/delayer.ts(34,5): Type '(value?: T | awaited T | PromiseLike<T> | undefined) => void' is not assignable to type '(value?: T | Thenable<T> | undefined) => void'.
  Types of parameters 'value' and 'value' are incompatible.
    Type 'T | Thenable<T> | undefined' is not assignable to type 'T | awaited T | PromiseLike<T> | undefined'.
      Type 'Thenable<T>' is not assignable to type 'T | awaited T | PromiseLike<T> | undefined'.
        Type 'Thenable<T>' is not assignable to type 'PromiseLike<T>'.
          Types of property 'then' are incompatible.
            Type '{ <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<TResult>) | undefined, onrejected?: ((reason: any) => TResult | Thenable<TResult>) | undefined): Thenable<...>; <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<...>) | undefined, onrejected?: ((reason: any) => void) | undefined): Thenable<...>; }' is not assignable to type '<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: awaited T) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => PromiseLike<...>'.
              Types of parameters 'onfulfilled' and 'onfulfilled' are incompatible.
                Type '((value: awaited T) => any) | null | undefined' is not assignable to type '((value: T) => any) | undefined'.
                  Type 'null' is not assignable to type '((value: T) => any) | undefined'.
[14:16:40] Error: /Users/matb/projects/vscode/extensions/github-authentication/src/common/utils.ts(64,3): Argument of type '(result: U) => U' is not assignable to parameter of type '(value: awaited U) => U | PromiseLike<U>'.
  Types of parameters 'result' and 'value' are incompatible.
    Type 'awaited U' is not assignable to type 'U'.
      'U' could be instantiated with an arbitrary type which could be unrelated to 'awaited U'.
[14:16:40] Error: /Users/matb/projects/vscode/extensions/git/src/util.ts(390,17): Argument of type '(value?: T | Promise<T> | undefined) => void' is not assignable to parameter of type '(value: awaited T) => void | PromiseLike<void>'.
  Types of parameters 'value' and 'value' are incompatible.
    Type 'awaited T' is not assignable to type 'T | Promise<T> | undefined'.
      Type 'awaited T' is not assignable to type 'Promise<T>'.
[14:16:40] Error: /Users/matb/projects/vscode/extensions/git/src/commands.ts(2567,3): Type '(awaited T)[]' is not assignable to type 'T[]'.
  Type 'awaited T' is not assignable to type 'T'.
    'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/extensions/typescript-language-features/src/utils/async.ts(34,5): Type '(value?: T | awaited T | PromiseLike<T> | undefined) => void' is not assignable to type '(value?: T | Thenable<T> | undefined) => void'.
  Types of parameters 'value' and 'value' are incompatible.
    Type 'T | Thenable<T> | undefined' is not assignable to type 'T | awaited T | PromiseLike<T> | undefined'.
      Type 'Thenable<T>' is not assignable to type 'T | awaited T | PromiseLike<T> | undefined'.
        Type 'Thenable<T>' is not assignable to type 'PromiseLike<T>'.
          Types of property 'then' are incompatible.
            Type '{ <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<TResult>) | undefined, onrejected?: ((reason: any) => TResult | Thenable<TResult>) | undefined): Thenable<...>; <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<...>) | undefined, onrejected?: ((reason: any) => void) | undefined): Thenable<...>; }' is not assignable to type '<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: awaited T) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => PromiseLike<...>'.
              Types of parameters 'onfulfilled' and 'onfulfilled' are incompatible.
                Type '((value: awaited T) => any) | null | undefined' is not assignable to type '((value: T) => any) | undefined'.
                  Type 'null' is not assignable to type '((value: T) => any) | undefined'.
[14:16:40] Error: /Users/matb/projects/vscode/extensions/php-language-features/src/features/utils/async.ts(69,29): Argument of type '(result: T) => void' is not assignable to parameter of type '(value: awaited T) => void | PromiseLike<void>'.
  Types of parameters 'result' and 'value' are incompatible.
    Type 'awaited T' is not assignable to type 'T'.
      'T' could be instantiated with an arbitrary type which could be unrelated to 'awaited T'.
[14:16:40] Error: /Users/matb/projects/vscode/extensions/php-language-features/src/features/utils/async.ts(125,5): Type '(value?: T | awaited T | PromiseLike<T> | undefined) => void' is not assignable to type '(value: T | Thenable<T> | undefined) => void'.
  Types of parameters 'value' and 'value' are incompatible.
    Type 'T | Thenable<T> | undefined' is not assignable to type 'T | awaited T | PromiseLike<T> | undefined'.
      Type 'Thenable<T>' is not assignable to type 'T | awaited T | PromiseLike<T> | undefined'.
        Type 'Thenable<T>' is not assignable to type 'PromiseLike<T>'.
          Types of property 'then' are incompatible.
            Type '{ <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<TResult>) | undefined, onrejected?: ((reason: any) => TResult | Thenable<TResult>) | undefined): Thenable<...>; <TResult>(onfulfilled?: ((value: T) => TResult | Thenable<...>) | undefined, onrejected?: ((reason: any) => void) | undefined): Thenable<...>; }' is not assignable to type '<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: awaited T) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<...>) | null | undefined) => PromiseLike<...>'.
              Types of parameters 'onfulfilled' and 'onfulfilled' are incompatible.
                Type '((value: awaited T) => any) | null | undefined' is not assignable to type '((value: T) => any) | undefined'.
                  Type 'null' is not assignable to type '((value: T) => any) | undefined'.

[mjbvz]

Looks like some of these are already tracked:

• searchModel.ts — Extraneous control flow error #37480

[rbuckton]

This is due to the inclusion of the new awaited type in the 3.9 nightlies and beta. We're working through breaks currently to determine next steps. I am looking to make a change to PromiseLike shortly that will revert the use of awaited there (since PromiseLike doesn't guarantee it is a Promise/A+ compatible promise), which may resolve this case.

[rbuckton]

I am looking into whether #37570 might address this.

[rbuckton]

It looks like #37540 may help as well, as it reduced the number of failures in our tests significantly: https://github.com/typescript-bot/TypeScript/pull/9/files#diff-0e62d568d28b82cee9e66b2b8fafd290R7

[peterblazejewicz]

We're working through breaks currently to determine next steps

This has a side effect on the DefinitelyTyped definitions as the CI and local tests include checks for the @next tag: https://github.com/definitelyTyped/DefinitelyTyped/
So some of the PR started to fail recently with an error mentioned:

Property 'then' in type 'Bluebird<R>' is not assignable to the same property in base type 'PromiseLike<R>'.

or:

Property 'then' in type 'MyPromise<T>' is not assignable to the same property in base type 'PromiseLike<T>'.
  Type '<TResult1 = T, TResult2 = never>(onfulfilled?: (value: T) => TResult1 | PromiseLike<TResult1>, onrejected?: (reason: any) => TResult2 | PromiseLike<TResult2>) => PromiseLike<...>' is not assignable to type '<TResult1 = T, TResult2 = never>(onfulfilled?: (value: awaited T) => TResult1 | PromiseLike<TResult1>, onrejected?: (reason: any) => TResult2 | PromiseLike<TResult2>) => PromiseLike<...>'.
    Types of parameters 'onfulfilled' and 'onfulfilled' are incompatible.
      Types of parameters 'value' and 'value' are incompatible.
        Type 'T' is not assignable to type 'awaited T'.

The impact is hard to asses, as for example jQuery type definitions contains a custom Promise-like definition, so any update for a package using jQuery definition as dependency will now fail under the CI or local tests against @next.

Let me know if you want more details,
Thanks!

[rbuckton]

@mjbvz We are reverting awaited for TS3.9 while we continue to assess its impact.

[mjbvz]

Ok, thanks for the quick followup. Let me know if you need any help understanding what the VS Code codebase is doing