ci(#365): run affected tests for pull request CI lanes (#366)

tests/affected-tests-lib.test.cjs

@@ -0,0 +1,86 @@
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const {
+  parseRelativeSpecifiers,
+  pickAffectedTests,
+  shouldRunFullSuite,
+  resolveBaseRef,
+} = require('../scripts/affected-tests-lib.cjs');
+
+test('parseRelativeSpecifiers captures local require/import paths', () => {
+  const source = `
+    const a = require('./alpha.cjs');
+    const b = require("node:assert/strict");
+    import c from "../beta.js";
+    import d from "external-lib";
+  `;
+  const out = parseRelativeSpecifiers(source);
+  assert.deepEqual(out, ['./alpha.cjs', '../beta.js']);
+});
+
+test('shouldRunFullSuite true when critical paths change', () => {
+  assert.equal(shouldRunFullSuite(['package-lock.json']), true);
+  assert.equal(shouldRunFullSuite(['.github/workflows/test.yml']), true);
+  assert.equal(shouldRunFullSuite(['tests/foo.test.cjs']), false);
+});
+
+test('pickAffectedTests includes direct test changes and reverse-index matches', () => {
+  const allTests = [
+    'tests/alpha.test.cjs',
+    'tests/install.test.cjs',
+    'tests/release-tarball-smoke.install.test.cjs',
+  ];
+  const reverse = new Map([
+    ['bin/install.js', new Set(['tests/install.test.cjs'])],
+  ]);
+  const selected = pickAffectedTests(
+    ['tests/alpha.test.cjs', 'bin/install.js'],
+    allTests,
+    reverse,
+    ['tests/release-tarball-smoke.install.test.cjs'],
+  );
+  assert.deepEqual(selected, [
+    'tests/alpha.test.cjs',
+    'tests/install.test.cjs',
+    'tests/release-tarball-smoke.install.test.cjs',
+  ]);
+});
+
+test('pickAffectedTests falls back to smoke test when no matches found', () => {
+  const allTests = ['tests/release-tarball-smoke.install.test.cjs'];
+  const selected = pickAffectedTests(
+    ['docs/README.md'],
+    allTests,
+    new Map(),
+    ['tests/release-tarball-smoke.install.test.cjs'],
+  );
+  assert.deepEqual(selected, ['tests/release-tarball-smoke.install.test.cjs']);
+});
+
+test('resolveBaseRef prefers explicit env override', () => {
+  const original = {
+    GSD_AFFECTED_BASE: process.env.GSD_AFFECTED_BASE,
+    GITHUB_BASE_REF: process.env.GITHUB_BASE_REF,
+  };
+  try {
+    process.env.GSD_AFFECTED_BASE = 'origin/next';
+    process.env.GITHUB_BASE_REF = 'main';
+    assert.equal(resolveBaseRef(), 'origin/next');
+
+    delete process.env.GSD_AFFECTED_BASE;
+    process.env.GITHUB_BASE_REF = 'next';
+    assert.equal(resolveBaseRef(), 'origin/next');
+
+    delete process.env.GSD_AFFECTED_BASE;
+    delete process.env.GITHUB_BASE_REF;
+    assert.equal(resolveBaseRef(), 'origin/main');
+  } finally {
+    if (original.GSD_AFFECTED_BASE === undefined) delete process.env.GSD_AFFECTED_BASE;
+    else process.env.GSD_AFFECTED_BASE = original.GSD_AFFECTED_BASE;
+    if (original.GITHUB_BASE_REF === undefined) delete process.env.GITHUB_BASE_REF;
+    else process.env.GITHUB_BASE_REF = original.GITHUB_BASE_REF;
+  }
+});