fix(action): better handle errors and output in process invoke (#26)

* chore(action): Clean up the README examples a bit

* fix(action): handle errors and outputs in the action js shim

* fix: write graphql call errors to stderr instead of stdout

* feat(action): add support for dry-run / --dry-run

Author: avidal

README.md

@@ -12,6 +12,11 @@ mutation.
 When this API is used with a GitHub App token, the resulting commit will be signed and verified by
 GitHub on behalf of the application.
 
+*NOTE:* One limitation of creating commits using the GraphQL API is that it does not expose any
+mechanism to set or change file modes. It merely takes the file contents, base64 encoded. This means
+that if you rely on `commit-headless` to push binary files (or executable scripts), the file in the
+resulting commit will not retain that executable bit.
+
 [mutation]: https://docs.github.com/en/graphql/reference/mutations#createcommitonbranch
 [action-branch]: https://github.com/DataDog/commit-headless/tree/action
 

action-template/README.md

@@ -27,7 +27,14 @@ If your workflow creates multiple commits and you want to push all of them, you
     git add bot.txt && git commit -m"bot commit 2"
 
     # List both commit hashes in reverse order, space separated
-    echo "commits=\"$(git log "${{ github.sha }}".. --format='%H%x00' | tr '\n' ' ')\"" >> $GITHUB_OUTPUT
+    echo "commits=\"$(git log "${{ github.sha }}".. --format='%H' | tr '\n' ' ')\"" >> $GITHUB_OUTPUT
+
+    # If you just have a single commit, you can do something like:
+    #  echo "commit=$(git rev-parse HEAD)" >> $GITHUB_OUTPUT
+    # and then use it in the action via:
+    #  with:
+    #    ...
+    #    commits: ${{ steps.create-commits.outputs.commit }}
 
 - name: Push commits
   uses: DataDog/commit-headless@action/v%%VERSION%%

action-template/action.js

@@ -24,13 +24,19 @@ function main() {
 
   const cmd = `${__dirname}/${binary}`
 
+  try {
+    fs.chmodSync(cmd, 0o755);
+  } catch (err) {
+    console.error(`Error making binary executable: ${err.message}`);
+  }
+
   const env = { ...process.env };
   env.HEADLESS_TOKEN = process.env.INPUT_TOKEN;
 
   const command = process.env.INPUT_COMMAND;
 
   if (!["commit", "push"].includes(command)) {
-    console.error(`Unknown command ${command}. Must be one of "commit" or "push".`);
+    console.error(`Unknown command '${command}'. Must be one of "commit" or "push".`);
     process.exit(1);
   }
 
@@ -45,6 +51,14 @@ function main() {
     args.push("--branch-from", branchFrom);
   }
 
+  const dryrun = process.env["INPUT_DRY-RUN"] || "false"
+  if(!["true", "false"].includes(dryrun.toLowerCase())) {
+    console.error(`Invalid value for dry-run (${dryrun}). Must be one of true or false.`);
+    process.exit(1);
+  }
+
+  if(dryrun.toLowerCase() === "true") { args.push("--dry-run") }
+
   if (command === "push") {
     args.push(...process.env.INPUT_COMMITS.split(/\s+/));
   } else {
@@ -66,6 +80,7 @@ function main() {
 
   const child = childProcess.spawnSync(cmd, args, {
     env: env,
+    // ignore stdin, capture stdout, stream stderr to the parent
     stdio: ['ignore', 'pipe', 'inherit'],
   })
 
@@ -77,13 +92,33 @@ function main() {
 
       const delim = `delim_${crypto.randomUUID()}`;
       fs.appendFileSync(process.env.GITHUB_OUTPUT, `pushed_ref<<${delim}${os.EOL}${out}${os.EOL}${delim}`, { encoding: "utf8" });
+      process.exit(0);
+    }
+  } else {
+    console.error(`Child process exited uncleanly with signal ${child.signal || "unknown" }`);
+    if(child.error) {
+      console.error(`  error: ${child.error}`);
     }
+    exitCode = 128;
+  }
 
-    process.exit(exitCode)
+  if(child.stdout) {
+    // commit-headless should never print anything to stdout *except* the pushed reference, but just
+    // in case we'll print whatever happens here
+    console.log("Child process output:");
+    console.log(child.stdout.toString().trim());
+    console.log();
   }
-  process.exit(1)
+
+  process.exit(exitCode);
+
 }
 
 if (require.main === module) {
-  main()
+  try {
+    main()
+  } catch (exc) {
+    console.error(`Unhandled exception running action, got: ${exc.message}`);
+    process.exit(1);
+  }
 }

action-template/action.yml

@@ -24,6 +24,9 @@ inputs:
   command:
     description: 'Command to run. One of "commit" or "push"'
     required: true
+  dry-run:
+    description: 'Stop processing just before actually making changes to the remote. Note that the pushed_ref output will be a zeroed commit hash.'
+    default: false
   commits:
     description: 'For push, the list of commit hashes to push, oldest first'
   files:

github.go

@@ -251,12 +251,12 @@ func (c *Client) PushChange(ctx context.Context, headCommit string, change Chang
 	}
 
 	if len(payload.Errors) != 0 {
-		fmt.Printf("There were %d errors returned when creating the commit.\n", len(payload.Errors))
-		fmt.Println("Input:")
-		fmt.Println(string(queryJSON))
-		for i, e := range payload.Errors {
-			fmt.Printf("Error %d: %s\n", i+1, e.Message)
+		log("There were %d errors returned when creating the commit.\n", len(payload.Errors))
+		for _, e := range payload.Errors {
+			log("  - %s\n", e.Message)
 		}
+
+		log("\nInput data, for reference: %s", string(queryJSON))
 		return "", errors.New("graphql response")
 	}
 

version.go

@@ -1,3 +1,3 @@
 package main
 
-const VERSION = "0.5.0"
+const VERSION = "0.5.1"