test: add CI workflow validation tests

Author: kenryu42

tests/scripts/ci-workflow.test.ts

@@ -0,0 +1,89 @@
+import { describe, expect, test } from 'bun:test';
+import { readFileSync } from 'node:fs';
+
+const REQUIRED_CI_INPUT_PATHS = [
+  '.github/workflows/**',
+  'src/**',
+  'scripts/**',
+  'tests/**',
+  'bun.lock',
+  'tsconfig.json',
+  'tsconfig.build.json',
+  'biome.json',
+  'knip.ts',
+  'sgconfig.yml',
+  'ast-grep/**',
+] as const;
+
+function readWorkflow(): string {
+  return readFileSync(new URL('../../.github/workflows/ci.yml', import.meta.url), 'utf8');
+}
+
+function extractPaths(workflow: string, eventName: 'push' | 'pull_request'): string[] {
+  const lines = workflow.split('\n');
+  const eventIndex = lines.findIndex((line) => line.trim() === `${eventName}:`);
+  if (eventIndex === -1) {
+    throw new Error(`Missing ${eventName} event in ci workflow`);
+  }
+
+  const eventIndent = lines[eventIndex]?.match(/^\s*/)?.[0].length ?? 0;
+  const eventLines: string[] = [];
+
+  for (const line of lines.slice(eventIndex + 1)) {
+    const trimmed = line.trim();
+    const indent = line.match(/^\s*/)?.[0].length ?? 0;
+    if (trimmed && indent <= eventIndent) {
+      break;
+    }
+    eventLines.push(line);
+  }
+
+  const pathsIndex = eventLines.findIndex((line) => line.trim() === 'paths:');
+  if (pathsIndex === -1) {
+    throw new Error(`Missing paths filter for ${eventName} in ci workflow`);
+  }
+
+  const pathsIndent = eventLines[pathsIndex]?.match(/^\s*/)?.[0].length ?? 0;
+  const paths: string[] = [];
+
+  for (const line of eventLines.slice(pathsIndex + 1)) {
+    const trimmed = line.trim();
+    const indent = line.match(/^\s*/)?.[0].length ?? 0;
+    if (trimmed && indent <= pathsIndent) {
+      break;
+    }
+    if (trimmed.startsWith('- ')) {
+      paths.push(trimmed.slice(2).replaceAll('"', ''));
+    }
+  }
+
+  return paths;
+}
+
+describe('CI workflow trigger filters', () => {
+  test('push still validates all build and static-analysis inputs', () => {
+    const pushPaths = extractPaths(readWorkflow(), 'push');
+
+    for (const requiredPath of REQUIRED_CI_INPUT_PATHS) {
+      expect(pushPaths).toContain(requiredPath);
+    }
+  });
+
+  test('push does not include generated release artifacts', () => {
+    const pushPaths = extractPaths(readWorkflow(), 'push');
+
+    expect(pushPaths).not.toContain('assets/**');
+    expect(pushPaths).not.toContain('package.json');
+  });
+
+  test('pull requests still validate workflow and package changes', () => {
+    const pullRequestPaths = extractPaths(readWorkflow(), 'pull_request');
+
+    for (const requiredPath of REQUIRED_CI_INPUT_PATHS) {
+      expect(pullRequestPaths).toContain(requiredPath);
+    }
+
+    expect(pullRequestPaths).toContain('assets/**');
+    expect(pullRequestPaths).toContain('package.json');
+  });
+});