build(integration): clone properly from the local repo when in a detached HEAD state

src/cli/tasks.ts

@@ -33,15 +33,21 @@ export const cloneRepo = (
 ) => {
   const projectDir = join(workingDirectory, dir);
   const gitHistoryDir = join(projectDir, '.git');
+  const args =
+    repoInfo.branch === '.'
+      ? ['clone', '--depth=1', repoInfo.repo, dir]
+      : [
+          'clone',
+          '--depth=1',
+          `--branch=${repoInfo.branch}`,
+          repoInfo.repo,
+          dir
+        ];
   try {
-    await spawner(
-      'git',
-      ['clone', '--depth=1', `--branch=${repoInfo.branch}`, repoInfo.repo, dir],
-      {
-        cwd: workingDirectory,
-        stdio: suppressOutput ? 'pipe' : 'inherit'
-      }
-    );
+    await spawner('git', args, {
+      cwd: workingDirectory,
+      stdio: suppressOutput ? 'pipe' : 'inherit'
+    });
   } catch (err) {
     if (err.code === 'ENOENT') {
       throw new Error(`

src/cli/tests/cli.integration.spec.ts

@@ -40,7 +40,8 @@ const branch = execa.sync('git', [
   'HEAD'
 ]).stdout;
 const repoInfo = {
-  branch: branch === 'HEAD' ? 'master' : branch,
+  // if local repo is in a detached HEAD state, providing --branch to `git clone` will fail.
+  branch: branch === 'HEAD' ? '.' : branch,
   repo: process.cwd()
 };
 const buildDir = join(process.cwd(), 'build');

src/cli/tests/cli.unit.spec.ts

@@ -138,7 +138,7 @@ const mockErr = (code?: string | number) =>
 
 test('cloneRepo: errors when Git is not installed on PATH', async t => {
   const error = await t.throws(
-    cloneRepo(mockErr('ENOENT'))({ repo: 'r', branch: 'b' }, 'd', 'p')
+    cloneRepo(mockErr('ENOENT'))({ repo: 'r', branch: '.' }, 'd', 'p')
   );
   t.regex(error.message, /Git is not installed on your PATH/);
 });