test: prefix git auth with "x-access-token:" when run in a GitHub Action

test/get-git-auth-url.test.js

@@ -244,6 +244,19 @@ test('Return the "https" formatted URL if "gitCredentials" is defined with "BITB
   );
 });
 
+test('Return the "https" formatted URL if "GITHUB_ACTION" is set', async t => {
+  const {cwd} = await gitRepo();
+
+  t.is(
+    await getAuthUrl({
+      cwd,
+      env: {...env, GITHUB_ACTION: 'foo', GITHUB_TOKEN: 'token'},
+      options: {branch: 'master', repositoryUrl: 'git@host.null:owner/repo.git'},
+    }),
+    'https://x-access-token:token@host.null/owner/repo.git'
+  );
+});
+
 test('Handle "https" URL with group and subgroup, with "GIT_CREDENTIALS"', async t => {
   const {cwd} = await gitRepo();