Many `ts.LanguageService` APIs accept a filename, for example
```ts
getQuickInfoAtPosition(fileName: string, position: number)
```
The requirement is that `fileName` is agnostic to the platform (Linux, Mac,
Windows, etc), and is always normalized to TypeScript's internal
`NormalizedPath`.
This is evident from the way these APIs are called from the language server:
```ts
private onHover(params: lsp.TextDocumentPositionParams) {
const lsInfo = this.getLSAndScriptInfo(params.textDocument);
if (lsInfo === undefined) {
return;
}
const {languageService, scriptInfo} = lsInfo;
const offset = lspPositionToTsPosition(scriptInfo, params.position);
const info = languageService.getQuickInfoAtPosition(scriptInfo.fileName, offset);
// ...
}
```
9fca9c6651/server/src/session.ts (L594)
Here `scriptInfo.fileName` is always a `ts.server.NormalizedPath`.
However, https://github.com/angular/angular/pull/39917 accidentally leaked
the platform-specific paths, and caused a mismatch between the incoming paths
and the paths stored in the internal data structure `fileToComponent`.
This PR fixes the bug by always normalizing the paths, and updating the
type to reflect the format of the underlying data.
Fixes https://github.com/angular/vscode-ng-language-service/issues/1063
PR Close#40492