fix(lsp): scan injected languages for diagnostics by HerringtonDarkholme · Pull Request #2528 · ast-grep/ast-grep

HerringtonDarkholme · 2026-03-10T19:39:13Z

Summary by CodeRabbit

New Features
- Diagnostics now scan multiple injected languages in a document and apply language-specific rules per injected context.
Refactor
- Public language interface updated to require parse-from-string capability, aligning implementations with the new trait requirement (public API update).
Tests
- Added test coverage for injected-language diagnostics and code-action fix application.

coderabbitai · 2026-03-10T19:39:32Z

📝 Walkthrough

Walkthrough

The LSP diagnostic flow now performs per-injected-language scans instead of a single global pass and requires FromStr on LSPLang. Diagnostics and fixes are aggregated across injected-language contexts; tests added to verify TypeScript-in-HTML diagnostics and code actions.

Changes

Cohort / File(s)	Summary
LSP Trait & Diagnostic Scanning `crates/lsp/src/lib.rs`	Adds `FromStr` bound to `LSPLang` trait and its impl; refactors diagnostics to gather injected languages, fetch language-specific rules, run per-injected-language scans, and aggregate diagnostics and fixes.
Injected Language Test `crates/lsp/tests/basic.rs`	Adds async test `test_injected_language_diagnostics` that opens HTML with injected TypeScript, waits for diagnostics, requests and applies a code action, and asserts the applied fix (alert → console.log).

Sequence Diagram

sequenceDiagram
    participant Client as LSP Client
    participant Server as LSP Server
    participant Gatherer as Injection Gatherer
    participant Rules as Rule Engine
    participant Scanner as Per-Lang Scanner
    participant Aggregator as Result Aggregator

    Client->>Server: Request diagnostics for document (HTML with TS)
    Server->>Gatherer: Collect injected-language contexts
    Gatherer-->>Server: [TypeScript, ...]
    loop for each injected language
        Server->>Rules: Get rules for language
        Rules-->>Server: Language-specific rule refs
        Server->>Scanner: Run scan on injected subtree
        Scanner-->>Server: (rule, matches) pairs
        Server->>Aggregator: Add diagnostics & fixes
    end
    Aggregator-->>Server: Aggregated diagnostics & code actions
    Server-->>Client: Publish diagnostics & respond to code action requests

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Possibly related issues

[feature] Support language injections in LSP diagnostics #2522: This PR implements per-injected-language LSP scanning, addressing the missing injection-aware diagnostics described in the issue.

Possibly related PRs

feat: resolve rule id for ScanResult #1707: Related changes to how scan results expose rules and how the LSP iterates over rule matches; likely connected to the refactor in crates/lsp/src/lib.rs.

Poem

🐰
I hop through nested code today,
Finding rules where scripts may play.
TypeScript tucked inside HTML’s nest,
Scanned with care and fixed the rest.
Hooray for diagnostics that know the way!

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 75.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'fix(lsp): scan injected languages for diagnostics' directly describes the main change—enabling language-injection-aware diagnostics scanning. It is clear, specific, and accurately represents the primary modification to the LSP diagnostic flow.

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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-lsp-injection

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coderabbitai

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

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

Inline comments:
In `@crates/lsp/src/lib.rs`:
- Around line 291-297: The code currently returns early when
rule_refs.is_empty(), which skips calling
CombinedScan::set_unused_suppression_rule and loses unused-suppression hints for
languages with zero rules; instead ensure the unused-suppression rule is always
set: create the unused_suppression_rule via
CombinedScan::unused_config(Severity::Hint, injected.lang().clone()) and call
CombinedScan::new(rule_refs) (or create an empty CombinedScan) and then call
scan.set_unused_suppression_rule(&unused_suppression_rule) before any early
continue or skip logic so that set_unused_suppression_rule runs even when
rule_refs.is_empty().

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 65bd0178-1fd1-45cf-8875-6a03f4c8eb01

📥 Commits

Reviewing files that changed from the base of the PR and between 1c1e989 and a119b4d.

📒 Files selected for processing (2)

crates/lsp/src/lib.rs
crates/lsp/tests/basic.rs

fix #2522

coderabbitai

♻️ Duplicate comments (1)

crates/lsp/src/lib.rs (1)

290-297: ⚠️ Potential issue | 🟡 Minor

Don’t skip unused-suppression scanning when a language has no rules.

The continue on Line 291 still bypasses set_unused_suppression_rule, so host or injected regions with zero configured rules lose the unused-suppression hint entirely. CombinedScan::new(rule_refs) needs to run even for an empty rule set here.

Suggested fix

       let rule_refs = rules.get_rule_from_lang(&path, injected.lang().clone());
-      if rule_refs.is_empty() {
-        continue;
-      }
       let unused_suppression_rule =
         CombinedScan::unused_config(Severity::Hint, injected.lang().clone());
       let mut scan = CombinedScan::new(rule_refs);
       scan.set_unused_suppression_rule(&unused_suppression_rule);

🤖 Prompt for AI Agents

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

In `@crates/lsp/src/lib.rs` around lines 290 - 297, The current early return skips
creating a CombinedScan and setting the unused-suppression hint when
rules.get_rule_from_lang(&path, injected.lang().clone()) yields an empty
rule_refs; remove the continue and always construct CombinedScan::new(rule_refs)
(even when empty), then call
scan.set_unused_suppression_rule(&unused_suppression_rule) using
CombinedScan::unused_config(Severity::Hint, injected.lang().clone()); this
ensures the unused-suppression hint is applied for host or injected regions with
zero configured rules while preserving existing logic that processes non-empty
rule sets.

🤖 Prompt for all review comments with AI agents

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

Duplicate comments:
In `@crates/lsp/src/lib.rs`:
- Around line 290-297: The current early return skips creating a CombinedScan
and setting the unused-suppression hint when rules.get_rule_from_lang(&path,
injected.lang().clone()) yields an empty rule_refs; remove the continue and
always construct CombinedScan::new(rule_refs) (even when empty), then call
scan.set_unused_suppression_rule(&unused_suppression_rule) using
CombinedScan::unused_config(Severity::Hint, injected.lang().clone()); this
ensures the unused-suppression hint is applied for host or injected regions with
zero configured rules while preserving existing logic that processes non-empty
rule sets.

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: a48e2562-6841-4d7f-a44c-3b84af7c6e8c

📥 Commits

Reviewing files that changed from the base of the PR and between a119b4d and 8e6230f.

📒 Files selected for processing (2)

crates/lsp/src/lib.rs
crates/lsp/tests/basic.rs

🚧 Files skipped from review as they are similar to previous changes (1)

crates/lsp/tests/basic.rs

codecov · 2026-03-10T22:05:20Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.48%. Comparing base (3830aa6) to head (8e6230f).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2528   +/-   ##
=======================================
  Coverage   84.47%   84.48%           
=======================================
  Files         113      113           
  Lines       18685    18686    +1     
=======================================
+ Hits        15784    15786    +2     
+ Misses       2901     2900    -1

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##### [\`v0.42.0\`](https://github.com/ast-grep/ast-grep/blob/HEAD/CHANGELOG.md#0420) - chore(deps): update dependency dprint to v0.53.0 [`#2547`](ast-grep/ast-grep#2547) - chore(deps): update rust crate tree-sitter to v0.26.7 [`#2541`](ast-grep/ast-grep#2541) - chore(deps): update dependency web-tree-sitter to v0.26.7 [`#2540`](ast-grep/ast-grep#2540) - chore(deps): update dependency [@types/node](https://github.com/types/node) to v24.12.0 [`#2518`](ast-grep/ast-grep#2518) - fix(deps): update rust crate tree-sitter-lua to 0.5.0 [`#2506`](ast-grep/ast-grep#2506) - chore(deps): update rust crate clap to v4.6.0 [`#2538`](ast-grep/ast-grep#2538) - fix(deps): update rust crate tree-sitter-scala to 0.25.0 [`#2536`](ast-grep/ast-grep#2536) - chore(deps): update dependency oxlint to v1.55.0 [`#2533`](ast-grep/ast-grep#2533) - chore(deps): update rust crate clap\_complete to v4.6.0 [`#2539`](ast-grep/ast-grep#2539) - chore(deps): update rust crate bit-set to v0.9.1 [`#2537`](ast-grep/ast-grep#2537) - chore(deps): update rust crate bit-set to 0.9.0 [`#2527`](ast-grep/ast-grep#2527) - chore(deps): update rust crate assert\_cmd to v2.2.0 [`#2529`](ast-grep/ast-grep#2529) - chore(deps): update rust crate tempfile to v3.27.0 [`#2531`](ast-grep/ast-grep#2531) - fix(lsp): scan injected languages for diagnostics [`#2528`](ast-grep/ast-grep#2528) - chore(deps): update dependency [@ast-grep/napi](https://github.com/ast-grep/napi) to v0.41.1 [`#2526`](ast-grep/ast-grep#2526) - chore(deps): update dependency oxlint to v1.52.0 [`#2524`](ast-grep/ast-grep#2524) - feat: support nth-child esquery [`#2546`](ast-grep/ast-grep#2546) - feat: support :is selector [`#2545`](ast-grep/ast-grep#2545) - feat: support :not selector [`#2544`](ast-grep/ast-grep#2544) - feat: support :has rule [`#2543`](ast-grep/ast-grep#2543) - fix(lsp): scan injected languages for diagnostics ([#2528](ast-grep/ast-grep#2528)) [`#2522`](ast-grep/ast-grep#2522) - feat: add parameterized util [`3d90372`](ast-grep/ast-grep@3d90372) - refactor: limit parameterized utils to globals [`2d69a34`](ast-grep/ast-grep@2d69a34) - refactor: move parameterized\_util [`c77e38d`](ast-grep/ast-grep@c77e38d) ##### [\`v0.41.1\`](https://github.com/ast-grep/ast-grep/blob/HEAD/CHANGELOG.md#0411) > 10 March 2026 - fix: lsp on change encounter deadlock [`#2511`](ast-grep/ast-grep#2511) - chore(deps): update dependency oxlint to v1.51.0 [`#2512`](ast-grep/ast-grep#2512) - chore(deps): update rust crate tempfile to v3.26.0 [`#2497`](ast-grep/ast-grep#2497) - chore(deps): update rust crate inquire to v0.9.4 [`#2498`](ast-grep/ast-grep#2498) - chore(deps): update dependency [@types/node](https://github.com/types/node) to v24.11.0 [`#2502`](ast-grep/ast-grep#2502) - chore(deps): update dependency dprint to v0.52.0 [`#2499`](ast-grep/ast-grep#2499) - fix: override severity on `rule` & `inline-rules` flags [`#2505`](ast-grep/ast-grep#2505) - chore(deps): update github artifact actions [`#2507`](ast-grep/ast-grep#2507) - chore(deps): update rust crate tree-sitter to v0.26.6 [`#2501`](ast-grep/ast-grep#2501) - chore(deps): update dependency web-tree-sitter to v0.26.6 [`#2500`](ast-grep/ast-grep#2500) - chore(deps): update dependency ava to v7 [`#2508`](ast-grep/ast-grep#2508) - chore(deps): update dependency oxlint to v1.50.0 [`#2495`](ast-grep/ast-grep#2495) - chore(deps): update dependency [@ast-grep/napi](https://github.com/ast-grep/napi) to v0.41.0 [`#2494`](ast-grep/ast-grep#2494) - fix: bump ls-types version [`#2525`](ast-grep/ast-grep#2525) - refactor: change versioned ast work [`a86b2ab`](ast-grep/ast-grep@a86b2ab) - fix: bump wasm-bindgen [`d23e334`](ast-grep/ast-grep@d23e334) - fix: fix wasm package [`0b92e94`](ast-grep/ast-grep@0b92e94) Renovate-Branch: renovate/2024.6-ast-grep-cli-0.x Change-Id: I91bcfa93167c7af0833afeb42df774621bad595c Priv-Id: ef06dc14816a639036bb167212251f765ce38ad8

coderabbitai Bot reviewed Mar 10, 2026

View reviewed changes

Comment thread crates/lsp/src/lib.rs

fix(lsp): scan injected languages for diagnostics

8e6230f

fix #2522

HerringtonDarkholme force-pushed the fix-lsp-injection branch from a119b4d to 8e6230f Compare March 10, 2026 19:54

coderabbitai Bot reviewed Mar 10, 2026

View reviewed changes

coderabbitai Bot mentioned this pull request Mar 11, 2026

fix(lsp): unused-suppression hints silently lost for languages with no configured rules #2530

Closed

HerringtonDarkholme added this pull request to the merge queue Mar 11, 2026

Merged via the queue into main with commit 6795104 Mar 11, 2026
6 checks passed

HerringtonDarkholme deleted the fix-lsp-injection branch March 11, 2026 03:25

HerringtonDarkholme mentioned this pull request Mar 11, 2026

[feature] Support language injections in LSP diagnostics #2522

Closed

coderabbitai Bot mentioned this pull request Apr 22, 2026

fix(lsp): report unused suppressions without rules #2607

Merged

coderabbitai Bot mentioned this pull request May 12, 2026

fix(lsp): buffer diagnostics during initialization race (#2638) #2640

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fix(lsp): scan injected languages for diagnostics#2528

fix(lsp): scan injected languages for diagnostics#2528
HerringtonDarkholme merged 1 commit into
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fix-lsp-injection

HerringtonDarkholme commented Mar 10, 2026 •

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Sequence Diagram

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