support pnp resolver

[gun-yu]

This PR adds support for PnP resolution.

#1875 in the previous discussion, I have internalized pnp-go into the repository.

Please note that the PR has become quite large due to the inclusion of the PnP source and test code. I apologize for the length and appreciate your understanding.

what is pnp

Yarn Plug’n’Play (PnP) is a dependency resolution system that removes the need for a traditional node_modules folder.
describe at #460

how to support

add pnp resolution config in host

type host struct {
	orchestrator *Orchestrator
	host         compiler.CompilerHost
	// Caches that last only for build cycle and then cleared out
	extendedConfigCache tsc.ExtendedConfigCache
	sourceFiles         parseCache[ast.SourceFileParseOptions, *ast.SourceFile]
	configTimes         collections.SyncMap[tspath.Path, time.Duration]

	// caches that stay as long as they are needed
	resolvedReferences parseCache[tspath.Path, *tsoptions.ParsedCommandLine]
	mTimes             *collections.SyncMap[tspath.Path, time.Time]
	resolvedReferences  parseCache[tspath.Path, *tsoptions.ParsedCommandLine]
	mTimes              *collections.SyncMap[tspath.Path, time.Time]
	pnpResolutionConfig *pnp.ResolutionConfig
}

add pnp branch in resolver.go

// resolveTypeReferenceDirective
// skip typeRoots because PnP knows exactly where each @types is located.
	if r.resolver.pnpResolutionConfig != nil {
		if resolvedFromNearestNodeModulesDirectory := r.loadModuleFromNearestNodeModulesDirectory(true /*typesScopeOnly*/); !resolvedFromNearestNodeModulesDirectory.shouldContinueSearching() {
			return r.createResolvedTypeReferenceDirective(resolvedFromNearestNodeModulesDirectory, true /*primary*/)
		}
	} else {
		if len(typeRoots) > 0 {
			if r.tracer != nil {
				r.tracer.write(diagnostics.Resolving_with_primary_search_path_0.Format(strings.Join(typeRoots, ", ")))
			}

// loadModuleFromNearestNodeModulesDirectory
if r.resolver.pnpResolutionConfig != nil {
			if result := r.loadModuleFromPNP(priorityExtensions, typesScopeOnly); !result.shouldContinueSearching() {
				return result
			}
		} else {
			if result := r.loadModuleFromNearestNodeModulesDirectoryWorker(priorityExtensions, mode, typesScopeOnly); !result.shouldContinueSearching() {
				return result
			}
		}

[gun-yu]

todo: add pnp support later

[gun-yu]

I change this function's interface

[gun-yu]

These test cases were taken from pnp-rs, but since they are relatively complex to run and maintain.
I think it would be fine to remove them if they’re not considered necessary.
Please let me know your thoughts!

[gun-yu]

@microsoft-github-policy-service agree

[gun-yu]

On second thought, this way I wouldn’t be able to take advantage of the cached VFS, so I’m thinking of moving its location instead.

[jakebailey]

You said some of this comes from pnp-rs. Is it a pure port? What is the license of that code? Do you own it? (You signed the CLA, but that may not be enough if it's not yours.)

[gun-yu]

@jakebailey
The original source code, pnp-rs, is licensed under the BSD 2-Clause License. As the ported code is derived from that source, it should also fall under the BSD 2-Clause License — I missed that part, thank you for pointing it out.

As far as I understand, this means I need to include the original author’s license and copyright notice in the comments.

Would this cause any issues? If everything is fine, I’ll go ahead and add the appropriate BSD 2-Clause License notice.

[jakebailey]

We could pull it, but would need to explicitly declare that dependence in some extra metadata to generate NOTICE.txt (something we have avoided entirely by ensuring all code was written by us from spec or tests, but it's not really different than other deps).

But you definitely need to declare that there are files derived from code under a different license.

[gun-yu]

@jakebailey
Sorry for the late reply. I just want to confirm my understanding—would it be sufficient to directly add a notice for the BSD 2-Clause License of pnp-rs in the NOTICE.txt file?

[jakebailey]

No, the files containing the code need to have headers with said license. For example, these tests:

typescript-go/internal/jsnum/ryu_test.go

Line 3 in a05e479

// Copyright 2018 Ulf Adams