fix(betterer 🐛): don't reinitialize an existing git repo (corrupts shared config in worktrees)

packages/betterer/src/fs/git.ts

@@ -105,12 +105,17 @@ export class BettererGitΩ implements BettererVersionControl {
   }
 
   private async _init(git: SimpleGit): Promise<void> {
+    if (await git.checkIsRepo()) {
+      return;
+    }
+
     const retries = 3;
     for (let i = 0; i < retries; i++) {
       try {
         await git.init();
+        return;
       } catch (error) {
-        if (i >= retries) {
+        if (i === retries - 1) {
           throw error;
         }
       }

test/worktree.spec.ts

@@ -0,0 +1,51 @@
+// eslint-disable-next-line require-extensions/require-extensions -- tests not ESM ready yet
+import { createFixture } from './fixture';
+
+import { simpleGit } from 'simple-git';
+
+describe('betterer', () => {
+  it('should not reinitialise the repository when run inside a git worktree', async () => {
+    const { betterer } = await import('@betterer/betterer');
+
+    const { resolve, cleanup } = await createFixture('worktree', {
+      'source/.betterer.js': `
+const { regexp } = require('@betterer/regexp');
+
+module.exports = {
+  test: () => regexp(/(\\/\\/\\s*HACK)/i).include('./src/**/*.ts')
+};
+      `,
+      'source/src/index.ts': `// HACK:`
+    });
+
+    const sourcePath = resolve('source');
+    const barePath = resolve('repo.git');
+    const worktreePath = resolve('worktree');
+
+    const source = simpleGit(sourcePath);
+    await source.init();
+    await source.addConfig('user.email', 'test@betterer.dev');
+    await source.addConfig('user.name', 'Betterer Test');
+    await source.add('.');
+    await source.commit('init');
+    const branch = (await source.revparse(['--abbrev-ref', 'HEAD'])).trim();
+
+    await simpleGit(resolve('.')).clone(sourcePath, barePath, ['--bare']);
+
+    const bare = simpleGit(barePath);
+    await bare.raw('worktree', 'add', worktreePath, branch);
+
+    expect((await bare.raw('config', '--get', 'core.bare')).trim()).toBe('true');
+
+    await betterer({
+      cwd: worktreePath,
+      configPaths: [resolve('worktree/.betterer.js')],
+      resultsPath: resolve('worktree/.betterer.results'),
+      workers: false
+    });
+
+    expect((await bare.raw('config', '--get', 'core.bare')).trim()).toBe('true');
+
+    await cleanup();
+  });
+});