In the past, the legacy (VE-based) language service would use a
`UrlResolver` instance to resolve file paths, primarily for compiler
resources like external templates. The problem with this is that the
UrlResolver is designed to resolve URLs in general, and so for a path
like `/a/b/#c`, `#c` is treated as hash/fragment rather than as part
of the path, which can lead to unexpected path resolution (f.x.,
`resolve('a/b/#c/d.ts', './d.html')` would produce `'a/b/d.html'` rather
than the expected `'a/b/#c/d.html'`).
This commit resolves the issue by using Node's `path` module to resolve
file paths directly, which aligns more with how resources are resolved
in the Ivy compiler.
The testing story here is not great, and the API for validating a file
path could be a little bit prettier/robust. However, since the VE-based
language service is going into more of a "maintenance mode" now that
there is a clear path for the Ivy-based LS moving forward, I think it is
okay not to spend too much time here.
Closes https://github.com/angular/vscode-ng-language-service/issues/892
Closes https://github.com/angular/vscode-ng-language-service/issues/1001
PR Close#39917
3b700985f0