Add vitest related to pre-commit with expensive test skipping (#7854)

## Summary
This PR improves the pre-commit hook performance by:
- Using `vitest related` to run only tests affected by changed files
- Adding ability to skip expensive tests (filter tests) during
pre-commit
- Providing a consistent mechanism for skipping expensive tests

## Changes
- Modified `lint-staged.config.mjs` to run `vitest related` with
`SKIP_EXPENSIVE_TESTS=true`
- Updated `test/filter-tests.ts` to use idiomatic `describe.skipIf()`
for conditional test execution
- Changed `test-min` script to use `SKIP_EXPENSIVE_TESTS` environment
variable instead of `--exclude`
- Updated `CLAUDE.md` with documentation about the new test workflow

## Impact
- Pre-commit hooks are now much faster as they:
  - Only run tests related to changed files
  - Skip 688 expensive filter tests
  - Use the same skipping mechanism as `npm run test-min`

## Testing
- ✅ Verified `vitest related` correctly identifies and runs related
tests
- ✅ Confirmed filter tests are skipped when `SKIP_EXPENSIVE_TESTS=true`
- ✅ Tested that full test suite still runs all tests when env var is not
set
- ✅ Pre-commit hooks work correctly with the new setup

🤖 Generated with [Claude Code](https://claude.ai/code)

---------

Co-authored-by: Claude <noreply@anthropic.com>

CLAUDE.md

@@ -84,6 +84,13 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
   - Write platform-specific assertions
   - Use path-agnostic checks
 
+### Test Execution with Expensive Test Skipping
+- The `SKIP_EXPENSIVE_TESTS=true` environment variable skips expensive tests (like filter tests)
+- Pre-commit hooks use `vitest related` to run only tests related to changed files
+- Use `npm run test-min` to run tests with expensive tests skipped
+- Use `npm run test` to run all tests including expensive ones
+- To mark tests as expensive, use: `describe.skipIf(process.env.SKIP_EXPENSIVE_TESTS === 'true')('Test suite', () => {...})`
+
 ## Compiler Testing Specifics
 - Mock filesystem operations when testing file I/O
 - Use `makeFakeCompilerInfo()` for creating test compiler configurations

CONTRIBUTING.md

@@ -36,7 +36,8 @@ when testing your changes locally.
     warnings.
 - If you're adding a new server-side component, please do your best to add a test to cover it. For client-side changes
   that's trickier.
-- Tests should run automatically as a pre-commit step. _You can disable this check with `git commit --no-verify` if
+- Tests should run automatically as a pre-commit step. The pre-commit hook runs only tests related to changed files
+  and skips expensive tests (like filter tests) for faster feedback. _You can disable this check with `git commit --no-verify` if
   needed_.
 - You can run `make check` to run both the linter and the code tests
 - Do a smoke test: Run `make` and ensure the site works as you'd expect. Concentrate on the areas you'd expect to have

lint-staged.config.mjs

@@ -1,4 +1,4 @@
 export default {
-    '*.ts': ['npm run lint', () => 'npm run ts-check'],
+    '*.ts': ['npm run lint', () => 'npm run ts-check', 'cross-env SKIP_EXPENSIVE_TESTS=true npx vitest related --run'],
     '*.{html,md,js}': ['npm run lint'],
 };

package.json

@@ -147,7 +147,7 @@
     "test-coverage": "vitest run --coverage",
     "test": "vitest run",
     "test:watch": "vitest",
-    "test-min": "vitest run --exclude test/filter-tests.ts",
+    "test-min": "cross-env SKIP_EXPENSIVE_TESTS=true vitest run",
     "check": "npm run ts-check && npm run lint-check && npm run check-frontend-imports && npm run test-min -- --reporter dot",
     "check-frontend-imports": "node ./etc/scripts/check-frontend-imports.js",
     "dev": "cross-env NODE_ENV=DEV node --no-warnings=ExperimentalWarning --import=tsx app.ts",

test/filter-tests.ts

@@ -29,7 +29,7 @@ import {describe, expect, it} from 'vitest';
 
 import {ParseFiltersAndOutputOptions} from '../types/features/filters.interfaces.js';
 
-import {processAsm, resolvePathFromTestRoot} from './utils.js';
+import {processAsm, resolvePathFromTestRoot, skipExpensiveTests} from './utils.js';
 
 const casesRoot = resolvePathFromTestRoot('filters-cases');
 const files = fs.readdirSync(casesRoot);
@@ -70,7 +70,7 @@ function testFilter(filename: string, suffix: string, filters: ParseFiltersAndOu
     }, 10000); // Bump the timeout a bit so that we don't fail for slow cases
 }
 
-describe('Filter test cases', () => {
+describe.skipIf(skipExpensiveTests)('Filter test cases', () => {
     if (process.platform === 'win32' || process.platform === 'darwin') {
         it('should skip filter-tests on Windows', () => {
             expect(true).toBe(true);

test/utils.ts

@@ -29,6 +29,9 @@ import {fileURLToPath} from 'node:url';
 import {afterEach, expect, onTestFinished} from 'vitest';
 import * as temp from '../lib/temp.js';
 
+// Check if expensive tests should be skipped (e.g., during pre-commit hooks)
+export const skipExpensiveTests = process.env.SKIP_EXPENSIVE_TESTS === 'true';
+
 import {CompilationEnvironment} from '../lib/compilation-env.js';
 import {CompilationQueue} from '../lib/compilation-queue.js';
 import {CC65AsmParser} from '../lib/parsers/asm-parser-cc65.js';