fix(github): Return remote commit hash for platformCommit=true (#16391

)

lib/modules/platform/github/index.ts

@@ -1693,8 +1693,8 @@ export async function commitFiles(
   config: CommitFilesConfig
 ): Promise<CommitSha | null> {
   const commitResult = await git.prepareCommit(config); // Commit locally and don't push
+  const { branchName, files } = config;
   if (!commitResult) {
-    const { branchName, files } = config;
     logger.debug(
       { branchName, files: files.map(({ path }) => path) },
       `Platform-native commit: unable to prepare for commit`
@@ -1706,7 +1706,9 @@ export async function commitFiles(
   if (!pushResult) {
     return null;
   }
-  // Because the branch commit was done remotely via REST API, now we git fetch it locally.
-  // We also do this step when committing/pushing using local git tooling.
-  return git.fetchCommit(config);
+  // Replace locally created branch with the remotely created one
+  // and return the remote commit SHA
+  await git.resetToCommit(commitResult.parentCommitSha);
+  const commitSha = await git.fetchCommit(config);
+  return commitSha;
 }

lib/util/git/index.ts

@@ -233,6 +233,12 @@ async function resetToBranch(branchName: string): Promise<void> {
   await git.raw(['clean', '-fd']);
 }
 
+// istanbul ignore next
+export async function resetToCommit(commit: string): Promise<void> {
+  logger.debug(`resetToCommit(${commit})`);
+  await git.raw(['reset', '--hard', commit]);
+}
+
 async function deleteLocalBranch(branchName: string): Promise<void> {
   await git.branch(['-D', branchName]);
 }
@@ -975,7 +981,7 @@ export async function fetchCommit({
   logger.debug(`Fetching branch ${branchName}`);
   try {
     const ref = `refs/heads/${branchName}:refs/remotes/origin/${branchName}`;
-    await gitRetry(() => git.fetch(['origin', ref, '--force']));
+    await gitRetry(() => git.pull(['origin', ref, '--force']));
     const commit = (await git.revparse([branchName])).trim();
     config.branchCommits[branchName] = commit;
     config.branchIsModified[branchName] = false;