fix(noUnusedImports): edge case ambient type

[ematipico]

Summary

Closes #7516

Code and tests added by Claude Code

Test Plan

Added new tests

Docs

[github-actions]

Parser conformance results on

js/262

Test result	main count	This PR count	Difference
Total	53002	53002	0
Passed	51782	51782	0
Failed	1178	1178	0
Panics	42	42	0
Coverage	97.70%	97.70%	0.00%

jsx/babel

Test result	main count	This PR count	Difference
Total	38	38	0
Passed	37	37	0
Failed	1	1	0
Panics	0	0	0
Coverage	97.37%	97.37%	0.00%

markdown/commonmark

Test result	main count	This PR count	Difference
Total	652	652	0
Passed	652	652	0
Failed	0	0	0
Panics	0	0	0
Coverage	100.00%	100.00%	0.00%

symbols/microsoft

Test result	main count	This PR count	Difference
Total	5466	5466	0
Passed	1915	1915	0
Failed	3551	3551	0
Panics	0	0	0
Coverage	35.03%	35.03%	0.00%

ts/babel

Test result	main count	This PR count	Difference
Total	636	636	0
Passed	568	568	0
Failed	68	68	0
Panics	0	0	0
Coverage	89.31%	89.31%	0.00%

ts/microsoft

Test result	main count	This PR count	Difference
Total	18875	18875	0
Passed	13014	13014	0
Failed	5860	5860	0
Panics	1	1	0
Coverage	68.95%	68.95%	0.00%

[coderabbitai]

Walkthrough

Fixes a false positive in the noUnusedImports linter rule when a local variable shadows an imported type namespace that remains in use within type annotations. The fix modifies the semantic analysis to correctly handle ambient reads for non-imported bindings that shadow type imports, and includes comprehensive test coverage for const, let, var, and nested shadowing scenarios.

Possibly related PRs

• #7282: Modifies semantic event handling in events.rs to correct how namespace and type imports with shadowing are recorded.

Suggested labels

A-Linter, L-JavaScript, A-Core

Suggested reviewers

• dyc3

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'fix(noUnusedImports): edge case ambient type' directly addresses the main change—fixing a false-positive in the noUnusedImports rule for an edge case involving ambient types.
Description check	✅ Passed	The description references issue #7516, mentions code and tests were added, and notes the test plan—all relevant to the changeset addressing the noUnusedImports false-positive.
Linked Issues check	✅ Passed	The PR successfully addresses issue #7516 by modifying the ambient read promotion logic in events.rs to handle non-imported bindings shadowing type imports, and adds five comprehensive test cases covering const, let, var, nested, and non-type shadowing scenarios.
Out of Scope Changes check	✅ Passed	All changes are directly related to fixing the noUnusedImports false-positive: semantic logic fix in events.rs, changelog entry, and five focused test cases validating the fix.

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✨ Finishing Touches

• 📝 Generate docstrings (stacked PR)
• 📝 Generate docstrings (commit on current branch)

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch fix/no-unused-imports-v3

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[coderabbitai]

🧹 Nitpick comments (1)

crates/biome_js_semantic/src/events.rs (1)

1019-1033: Please add a dedicated parameter-shadowing regression test.

This branch explicitly handles the (stream: stream.T) shape; adding a matching valid-issue-7516-parameter.ts would lock the behaviour down and avoid future drift.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@crates/biome_js_semantic/src/events.rs` around lines 1019 - 1033, Add a
regression test that covers the parameter-shadowing case handled by the new
logic: create a new test file (e.g., valid-issue-7516-parameter.ts) containing a
type import and a function/arrow parameter that shadows the import name but uses
the import in a type position (the `(stream: stream.T)` shape), ensuring the
analyzer accepts it (valid test). The test should exercise the code path where
reference.is_ambient_read() && !info.is_imported() leads to promoting the
reference into the parent scope (verify behavior tied to self.scopes.last_mut(),
parent.references and Reference::AmbientRead). Ensure the test asserts no error
is reported so future changes to the promotion logic are caught.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@crates/biome_js_semantic/src/events.rs`:
- Around line 1019-1033: Add a regression test that covers the
parameter-shadowing case handled by the new logic: create a new test file (e.g.,
valid-issue-7516-parameter.ts) containing a type import and a function/arrow
parameter that shadows the import name but uses the import in a type position
(the `(stream: stream.T)` shape), ensuring the analyzer accepts it (valid test).
The test should exercise the code path where reference.is_ambient_read() &&
!info.is_imported() leads to promoting the reference into the parent scope
(verify behavior tied to self.scopes.last_mut(), parent.references and
Reference::AmbientRead). Ensure the test asserts no error is reported so future
changes to the promotion logic are caught.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 8d857a24-a300-4a5d-b20e-cc395a73cff6

📥 Commits

Reviewing files that changed from the base of the PR and between 64ce544 and d83f186.

⛔ Files ignored due to path filters (5)

• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-const.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-let.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-nested.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-non-type.ts.snap is excluded by !**/*.snap and included by **
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-var.ts.snap is excluded by !**/*.snap and included by **

📒 Files selected for processing (7)

• .changeset/rude-pets-enjoy.md
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-const.ts
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-let.ts
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-nested.ts
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-non-type.ts
• crates/biome_js_analyze/tests/specs/correctness/noUnusedImports/valid-issue-7516-var.ts
• crates/biome_js_semantic/src/events.rs

[codspeed-hq]

Merging this PR will not alter performance

✅ 58 untouched benchmarks
⏩ 156 skipped benchmarks¹

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_{Comparing fix/no-unused-imports-v3 (d83f186) with main (70c2d4e)}

Footnotes

1. 156 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩