Compile errors in VS Code codebase with latest TS nightly

[mjbvz]

🕗 Version & Regression Information

• This changed between versions 4.2.0-dev.20201207 and 4.2.0-dev.20210105

Repo

• Update VS Code to use the latest nightly TypeScript version (yarn add typescript@next)
• Run compile in the codebase yarn run watch

Issue

This produces around 16 compile errors. Most of these look like false positives to me:

[21:49:47] Error: vscode/src/vs/workbench/contrib/files/browser/views/explorerViewer.ts(1232,24): The left-hand side of an 'instanceof' expression must be of type 'any', an object type or a type parameter.
[21:49:47] Error: vscode/src/vs/workbench/contrib/files/browser/views/explorerViewer.ts(1232,72): Argument of type 'undefined' is not assignable to parameter of type 'Uint8Array'.
[21:49:47] Error: vscode/src/vs/base/browser/ui/dropdown/dropdownActionViewItem.ts(176,99): Property 'getActions' does not exist on type 'readonly IAction[] | IActionProvider'.
  Property 'getActions' does not exist on type 'readonly IAction[]'.
[21:49:47] Error: vscode/src/vs/base/browser/ui/actionbar/actionbar.ts(267,9): Type '(readonly IAction[] & any[]) | (IAction & any[]) | (IAction | readonly IAction[])[]' is not assignable to type 'readonly IAction[]'.
  Type '(IAction | readonly IAction[])[]' is not assignable to type 'readonly IAction[]'.
    Type 'IAction | readonly IAction[]' is not assignable to type 'IAction'.
      Type 'readonly IAction[]' is missing the following properties from type 'IAction': id, label, tooltip, class, and 4 more.
[21:49:47] Error: vscode/src/vs/workbench/api/common/extHostTypeConverters.ts(1249,24): Property 'language' does not exist on type 'DocumentFilter | readonly (string | DocumentFilter)[]'.
  Property 'language' does not exist on type 'readonly (string | DocumentFilter)[]'.
[21:49:47] Error: vscode/src/vs/workbench/api/common/extHostTypeConverters.ts(1250,22): Property 'scheme' does not exist on type 'DocumentFilter | readonly (string | DocumentFilter)[]'.
  Property 'scheme' does not exist on type 'readonly (string | DocumentFilter)[]'.
[21:49:47] Error: vscode/src/vs/workbench/api/common/extHostTypeConverters.ts(1251,30): Property 'pattern' does not exist on type 'DocumentFilter | readonly (string | DocumentFilter)[]'.
  Property 'pattern' does not exist on type 'readonly (string | DocumentFilter)[]'.
[21:49:47] Error: vscode/src/vs/workbench/api/common/extHostTypeConverters.ts(1251,94): Property 'pattern' does not exist on type 'DocumentFilter | readonly (string | DocumentFilter)[]'.
  Property 'pattern' does not exist on type 'readonly (string | DocumentFilter)[]'.
[21:49:47] Error: vscode/src/vs/workbench/api/common/extHostTypeConverters.ts(1252,25): Property 'exclusive' does not exist on type 'DocumentFilter | readonly (string | DocumentFilter)[]'.
  Property 'exclusive' does not exist on type 'readonly (string | DocumentFilter)[]'.
[21:49:47] Error: vscode/src/vs/workbench/api/common/extHost.api.impl.ts(199,26): Property 'scheme' does not exist on type 'DocumentFilter | readonly (string | DocumentFilter)[]'.
  Property 'scheme' does not exist on type 'readonly (string | DocumentFilter)[]'.
[21:49:47] Error: vscode/src/vs/workbench/api/common/extHost.api.impl.ts(202,58): Property 'exclusive' does not exist on type 'DocumentFilter | readonly (string | DocumentFilter)[]'.
  Property 'exclusive' does not exist on type 'readonly (string | DocumentFilter)[]'.
[21:49:47] Error: vscode/src/vs/editor/common/modes/languageSelector.ts(58,11): Property 'language' does not exist on type 'LanguageFilter | readonly (string | LanguageFilter)[]'.
[21:49:47] Error: vscode/src/vs/editor/common/modes/languageSelector.ts(58,21): Property 'pattern' does not exist on type 'LanguageFilter | readonly (string | LanguageFilter)[]'.
[21:49:47] Error: vscode/src/vs/editor/common/modes/languageSelector.ts(58,30): Property 'scheme' does not exist on type 'LanguageFilter | readonly (string | LanguageFilter)[]'.
[21:49:47] Error: vscode/src/vs/editor/common/modes/languageSelector.ts(58,38): Property 'hasAccessToAllModels' does not exist on type 'LanguageFilter | readonly (string | LanguageFilter)[]'.
[21:49:47] Error: vscode/src/vs/editor/common/modes/languageFeatureRegistry.ts(28,21): Property 'exclusive' does not exist on type 'LanguageFilter | readonly (string | LanguageFilter)[]'.
  Property 'exclusive' does not exist on type 'readonly (string | LanguageFilter)[]'.

[mjbvz]

Note that after installing typescript@next, you may run into this compile error: google/tsec#20 (which is not related to VS Code directly)

[ajafff]

Duplicate of #41808

[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.