feat: log git error message when authentication verification fails

lib/get-git-auth-url.js

@@ -43,7 +43,9 @@ module.exports = async ({repositoryUrl, branch}) => {
   }
 
   // Test if push is allowed without transforming the URL (e.g. is ssh keys are set up)
-  if (!await verifyAuth(repositoryUrl, branch)) {
+  try {
+    await verifyAuth(repositoryUrl, branch);
+  } catch (err) {
     const envVar = Object.keys(GIT_TOKENS).find(envVar => !isUndefined(process.env[envVar]));
     const gitCredentials = `${GIT_TOKENS[envVar] || ''}${process.env[envVar] || ''}`;
     const {protocols, ...parsed} = gitUrlParse(repositoryUrl);
@@ -52,5 +54,6 @@ module.exports = async ({repositoryUrl, branch}) => {
     // If credentials are set via anvironment variables, convert the URL to http/https and add basic auth, otherwise return `repositoryUrl` as is
     return gitCredentials ? {...parsed, protocols: [protocol], user: gitCredentials}.toString(protocol) : repositoryUrl;
   }
+
   return repositoryUrl;
 };

lib/git.js

@@ -86,13 +86,14 @@ async function isGitRepo() {
  * @param {String} repositoryUrl The remote repository URL.
  * @param {String} branch The repositoru branch for which to verify write access.
  *
- * @return {Boolean} `true` is authorized to push, falsy otherwise.
+ * @throws {Error} if not authorized to push.
  */
 async function verifyAuth(repositoryUrl, branch) {
   try {
-    return (await execa('git', ['push', '--dry-run', repositoryUrl, `HEAD:${branch}`])).code === 0;
+    await execa('git', ['push', '--dry-run', repositoryUrl, `HEAD:${branch}`]);
   } catch (err) {
     debug(err);
+    throw err;
   }
 }