Execute scoped deploy action reliably

.gitea/actions/quickstack-oci/deploy.mjs

@@ -259,6 +259,27 @@ export function validateTarget(target) {
   };
 }
 
+export function resolveDeploymentBranch({ eventName, environment = process.env, eventPayload } = {}) {
+  if (eventName !== "pull_request") {
+    return requiredString(environment.GITHUB_REF_NAME || environment.GITEA_REF_NAME, "Git branch");
+  }
+
+  const direct = String(environment.GITHUB_BASE_REF || environment.GITEA_BASE_REF || "").trim();
+  if (direct) return direct;
+
+  let payload = eventPayload;
+  if (payload === undefined) {
+    const eventPath = String(environment.GITHUB_EVENT_PATH || environment.GITEA_EVENT_PATH || "").trim();
+    if (eventPath) {
+      payload = JSON.parse(fs.readFileSync(eventPath, "utf8"));
+    }
+  }
+  return requiredString(
+    payload?.pull_request?.base?.ref || payload?.pull_request?.base?.repo?.default_branch,
+    "Pull request base branch",
+  );
+}
+
 function appendSummary(text) {
   const summary = process.env.GITHUB_STEP_SUMMARY ?? process.env.GITEA_STEP_SUMMARY;
   if (summary) fs.appendFileSync(summary, `${text}\n`);
@@ -273,10 +294,8 @@ async function main() {
   }
   const config = JSON.parse(fs.readFileSync(configPath, "utf8"));
   const eventName = process.env.GITHUB_EVENT_NAME ?? process.env.GITEA_EVENT_NAME ?? "";
-  const branch = eventName === "pull_request"
-    ? process.env.GITHUB_BASE_REF ?? process.env.GITEA_BASE_REF
-    : process.env.GITHUB_REF_NAME ?? process.env.GITEA_REF_NAME;
-  const deployment = selectDeployment(config, requiredString(branch, "Git branch"));
+  const branch = resolveDeploymentBranch({ eventName });
+  const deployment = selectDeployment(config, branch);
   if (!deployment) {
     console.log(`No deployment is declared for branch ${branch}.`);
     return;
@@ -351,7 +370,9 @@ async function main() {
   }
 }
 
-if (process.argv[1] && path.resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
+const invokedPath = process.argv[1] ? fs.realpathSync(process.argv[1]) : "";
+const modulePath = fs.realpathSync(fileURLToPath(import.meta.url));
+if (invokedPath === modulePath) {
   main().catch((error) => {
     console.error(error instanceof Error ? error.message : String(error));
     process.exitCode = 1;