[Ryan Cavanaugh (RyanCavanaugh)]

Part of #65068 (comment 3: panic handling request textDocument/completion: path must not contain a URL query or fragment from getCompletionEntriesForNonRelativeModules → getCompletionEntriesForDirectoryFragment → RootedDirectoryPath.ResolveDirectory)

Analysis

Module specifiers that look like URLs are only routed to the "relative" completion path when paths is not set:

if isPathRelativeToScript(literalValue) ||
	(options.Paths.Size() == 0 && (tspath.IsRootedDiskPath(literalValue) || tspath.IsUrl(literalValue))) {

So in a project with any paths mapping (e.g. the very common "@/*": ["./src/*"]) and bundler/node16/nodenext resolution, completing inside

import {} from "https://esm.sh/foo?alias=react:preact/|";
import {} from "https://esm.sh/foo#react/|";

goes through getCompletionEntriesForNonRelativeModules. The fragment directory (https://esm.sh/foo?alias=react:preact/) is a URL whose query/fragment is part of the "directory". For each ancestor that has a node_modules folder, ancestorLookup passes the fragment to getCompletionEntriesForDirectoryFragment, which calls nodeModules.ResolveDirectory(fragment). Because the fragment is itself rooted, resolution yields the URL unchanged, and tspath.ToRootedPath panics since a RootedPath must never contain a URL query or fragment.

The same input with a wildcard mapping ("*": ["./src/*"]) hits the same problem one step earlier, in getModulesForPathsPattern: CombinePaths(prefixDirectory, fragmentDirectory) returns the rooted URL and packageDirectory.ResolveDirectory(...) panics.

In 6.0 (src/services/stringCompletions.ts) these paths are just resolved to the URL string; tryDirectoryExists / tryReadDirectory then find nothing, so no file-system completions are produced from them.

Fix

Add a small isURLWithQueryOrFragment helper (a URL path that tspath.TryRootedPathFromAbsolute rejects, i.e. exactly the condition the tspath assertion fires on) and use it to skip directory lookups that can never exist:

• In getCompletionEntriesForNonRelativeModules, skip listing node_modules/<fragment> when the fragment directory is such a URL. The package.json imports/exports lookups still run as before.
• In getModulesForPathsPattern, return no matches when the expanded prefix directory is such a URL.

This matches 6.0's observable behavior (no file completions from those directories; ambient-module and other completions are unaffected) and leaves the tspath assertion intact.

Alternatives considered: guarding inside getCompletionEntriesForDirectoryFragment would also fix the reported stack, but that function is shared with relative-module completion, whose crash from #65068 is being fixed separately; keeping the guards in the non-relative callers avoids overlapping changes (if that fix lands, the node_modules guard here becomes redundant but harmless). Weakening the tspath assertion was ruled out.

Tests (new file tsc/internal/fourslash/tests/completionsPaths_nonRelativeUrlWithQuery_test.go):

• TestCompletionsPaths_nonRelativeUrlWithQuery reproduces the reported stack exactly (panicked before the fix).
• TestCompletionsPaths_nonRelativeUrlWithQueryWildcardPathMapping covers the getModulesForPathsPattern variant. It uses require(...) in a .ts file (not resolved during program construction) because, with a "*" mapping, an import of such a URL currently also panics in module resolution (tryLoadModuleUsingPaths → resolutionCandidateFromDirectoryPath), which is a separate crash outside the scope of this PR.

Copilot Checklist

I successfully ran the applicable command at the end of my session, and it completed without error:

• npx hereby validate
• npx hereby validate --api (for TypeScript API changes)

[Copilot]

🟢 Approval recommended

No active review issues are recorded for the URL module-specifier completion crash fix.

No open issues 🎉

What changed in this PR

Fixes a language-server completion crash for URL module specifiers containing queries or fragments when paths mappings are configured, addressing part of #65068.

Changes:

• Skips invalid URL directory lookups in non-relative module completions and wildcard path expansion, preserving rooted-path assertions.
• Adds fourslash regression tests for query and fragment URLs with both alias and wildcard mappings.

File	Description
tsc/​internal/​ls/​string_completions.go	Adds a URL validation helper and guards both affected directory lookups.
tsc/​internal/​fourslash/​tests/​completionsPaths_nonRelativeUrlWithQuery_test.go	Verifies empty completion results without crashes for both mapping scenarios.

_{Review effort: Balanced}