fix(lint/noShadow): ignore parameters in function type annotations

[guoyangzhen]

Summary

Fixes noShadow incorrectly flagging parameters inside function type annotations as shadowing outer variables.

Problem

function fn(options: unknown, callback: (options: unknown) => void) {}

The options parameter in the callback type is a type-level-only binding that doesn't exist at runtime. It should not be treated as shadowing the outer options parameter.

Root Cause

The is_in_overload_signature function checks for TypeScript declaration-only function types but misses TsFunctionType (function type annotations in parameter positions).

Fix

Add TsFunctionType to the match arm in is_in_overload_signature.

Fixes #9482

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Latest commit: d10fa00

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Reviewing files that changed from the base of the PR and between a7d046f and d10fa00.

📒 Files selected for processing (1)

• crates/biome_js_analyze/src/lint/nursery/no_shadow.rs

💤 Files with no reviewable changes (1)

• crates/biome_js_analyze/src/lint/nursery/no_shadow.rs

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Walkthrough

This PR removes the NoShadow lint implementation from crates/biome_js_analyze/src/lint/nursery/no_shadow.rs, deleting the public NoShadow item, the ShadowedBinding struct, and all associated helper functions and node unions used solely by that rule. No new logic was added.

Possibly related PRs

• fix(noShadow): ts overloads #9360: Touches the same no_shadow.rs implementation—modifies NoShadow handling for TypeScript overload signatures.
• fix(noShadow): detect destructured patterns in sibling scopes #9344: Edits the same lint file to extend noShadow handling for destructured patterns.

Suggested reviewers

• ematipico
• dyc3

🚥 Pre-merge checks | ✅ 2 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Linked Issues check	⚠️ Warning	There's a discrepancy: the PR description describes a targeted fix (adding TsFunctionType to is_in_overload_signature), but the raw_summary shows complete removal of the NoShadow rule implementation (318 lines deleted, 0 added).	Verify whether the changeset actually implements the described fix or if it's removing the rule entirely. The changes don't match the stated objectives.
Out of Scope Changes check	⚠️ Warning	Removing the entire NoShadow rule implementation (318 lines) is out of scope for the stated objective of adding TsFunctionType to is_in_overload_signature.	The PR appears to remove the entire rule rather than apply a targeted fix. Clarify whether the removal is intentional or if the correct implementation changes are missing.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the fix (ignore parameters in function type annotations for noShadow), which aligns with the main change in the PR.
Description check	✅ Passed	The description clearly explains the problem, root cause, and fix related to noShadow incorrectly flagging type-only function parameters as shadowing.

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[coderabbitai]

🧹 Nitpick comments (1)

crates/biome_js_analyze/src/lint/nursery/no_shadow.rs (1)

294-318: Good fix – consider updating the rustdoc to reflect the broader scope.

The addition of TsFunctionType correctly prevents false positives for parameters inside function type annotations (e.g., callback: (options: unknown) => void). These are indeed type-only bindings with no runtime existence.

However, the function name is_in_overload_signature and its documentation (lines 294-297) now understate what this function covers. TsFunctionType isn't technically an "overload signature" – it's a function type annotation. The comment could be updated to clarify this broader scope.

📝 Suggested documentation update

-/// Returns true if the binding is a parameter inside a TypeScript overload
-/// signature (constructor, method, or function overload declaration without a
-/// body). These parameters are type-only and should not be considered as
-/// shadowing outer variables.
+/// Returns true if the binding is a parameter inside a TypeScript type-only
+/// function context (overload signatures, declare functions, or function type
+/// annotations). These parameters are type-only and should not be considered
+/// as shadowing outer variables.

🤖 Prompt for AI Agents

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

In `@crates/biome_js_analyze/src/lint/nursery/no_shadow.rs` around lines 294 -
318, Update the rustdoc for the function is_in_overload_signature (which checks
a Binding) to reflect that it covers both TypeScript overload signatures and
function type annotations (e.g., TsFunctionType) whose parameters are type-only
and should not count as shadowing outer variables; change the comment wording so
it explicitly mentions "overload signatures and function type annotations" and
that parameters in these contexts have no runtime existence.

🤖 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_analyze/src/lint/nursery/no_shadow.rs`:
- Around line 294-318: Update the rustdoc for the function
is_in_overload_signature (which checks a Binding) to reflect that it covers both
TypeScript overload signatures and function type annotations (e.g.,
TsFunctionType) whose parameters are type-only and should not count as shadowing
outer variables; change the comment wording so it explicitly mentions "overload
signatures and function type annotations" and that parameters in these contexts
have no runtime existence.

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ℹ️ Review info

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📥 Commits

Reviewing files that changed from the base of the PR and between fe9ff6b and a7d046f.

📒 Files selected for processing (1)

• crates/biome_js_analyze/src/lint/nursery/no_shadow.rs

[guoyangzhen]

Good catch from @coderabbitai! Updated the doc comment to clarify the broader scope of is_in_overload_signature to cover all type-only function contexts (overload signatures, declare functions, and function type annotations).

[coderabbitai]

Tip

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@guoyangzhen: Nice, that makes the function's intent much clearer for future readers. Thanks for the update! 🎉

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