lsp-test-correlation

Requires the agent-lsp MCP server.

lsp-test-correlation

Discover which tests cover a source file, then run only those tests. Faster than running the full suite when you've changed one or two files and want targeted feedback.

When to use

• After editing a source file: "Which tests do I need to run for this change?"
• Before committing: run only the tests that cover what you touched
• Debugging a failure: find which test file corresponds to a broken source file
• Code review: understand what test coverage exists for a file before merging

Use /lsp-verify instead when you want to run the full suite and check all three layers (diagnostics + build + tests). Use this skill when you want fast, scoped test execution.

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Workflow

Step 1 — Find correlated test files

Call get_tests_for_file for each edited source file:

mcp__lsp__get_tests_for_file({ "file_path": "/abs/path/to/source.go" })

Returns the test files that correspond to the source file. For multiple edited files, call once per file.

If no test files are returned: the source file may have no dedicated test file, or the mapping is not resolvable (e.g. integration tests in a separate directory). See Step 2 for fallback.

Step 2 — Enumerate test functions (fallback or enrichment)

If get_tests_for_file returns test files, use find_symbol to list the test functions defined in those files:

mcp__lsp__find_symbol({ "query": "Test" })

Filter results to the correlated test files from Step 1. This gives you the specific test function names to run rather than the whole test file.

Fallback (no test files found): query find_symbol for test functions that contain the changed symbol's name:

mcp__lsp__find_symbol({ "query": "Test<ChangedFunctionName>" })

This catches cases where get_tests_for_file misses indirect coverage.

Step 3 — Report the correlation map

Before running, report what was found:

## Test correlation for <file>

Source file: internal/tools/analysis.go
Test files:
  → internal/tools/analysis_test.go
     Tests: TestHandleGetCodeActions, TestHandleGetCompletions, TestHandleGetDocumentSymbols

No correlated test files found for: internal/lsp/normalize.go
  → Fallback: TestNormalizeCompletion, TestNormalizeDocumentSymbols (from workspace symbol search)

If the user provided run=true or asks to run, proceed to Step 4. Otherwise stop here and let the user decide.

Step 4 — Run correlated tests

Run only the correlated test files or functions. Scope as tightly as possible:

Go — run specific package:

mcp__lsp__run_tests({ "workspace_dir": "<root>", "test_filter": "TestHandleGetCodeActions|TestHandleGetCompletions" })

If run_tests does not support test_filter, pass the package path instead of the workspace root to narrow scope. The test output will be smaller and faster than running ./....

Output handling: If test output is large, do not read it in full. Search for failures:

grep -E "^(FAIL|--- FAIL)" <output_file>

Step 5 — Report results

## Test Results

Ran 3 tests in internal/tools/analysis_test.go

PASSED (2):
  TestHandleGetCodeActions
  TestHandleGetCompletions

FAILED (1):
  TestHandleGetDocumentSymbols — expected 3 symbols, got 2 (analysis_test.go:87)

Recommendation: Fix TestHandleGetDocumentSymbols before committing.

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Multi-file workflow

For changes spanning multiple source files:

1. Call get_tests_for_file for each changed file in parallel.
2. Deduplicate the resulting test files (the same test file may cover multiple source files).
3. Report the full correlation map before running.
4. Run the deduplicated test set once.

## Test correlation for 3 changed files

internal/tools/analysis.go      → internal/tools/analysis_test.go
internal/lsp/client.go          → internal/lsp/client_test.go, internal/lsp/client_completion_test.go
internal/resources/resources.go → (no dedicated test file)

Deduplicated test files to run: 3

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Decision guide

Situation	Action
get_tests_for_file returns test files	Use those; enumerate functions via find_symbol
No test files returned	Fallback to find_symbol with changed symbol names
Test files found but no matching test functions	Report gap — this source file may lack unit test coverage
More than 10 test files returned	Don't run all; use /lsp-verify for full suite instead
Test fails	Run /lsp-verify for full diagnostic picture

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Example

# "I edited internal/tools/symbol_source.go — which tests should I run?"

get_tests_for_file(file_path="/repo/internal/tools/symbol_source.go")
  → internal/tools/symbol_source_test.go

find_symbol(query="TestGetSymbolSource")
  → TestGetSymbolSource_ContainsPosition (line 12)
  → TestGetSymbolSource_FindInnermost (line 34)
  → TestGetSymbolSource_PositionPattern (line 67)

# Report correlation, then run:
run_tests(workspace_dir="/repo", test_filter="TestGetSymbolSource")
  → 3 passed in 0.4s