Update start.js for pass code from start.sh (#45)

.github/workflows/build.yml

@@ -15,4 +15,4 @@ jobs:
       uses: './'
       with:
         github_token: '${{ secrets.GITHUB_TOKEN }}'
-        branch: '${{ github.ref }}'
+        branch: '${{ github.ref }}'

start.js

@@ -4,7 +4,14 @@ const path = require("path");
 const exec = (cmd, args=[]) => new Promise((resolve, reject) => {
     console.log(`Started: ${cmd} ${args.join(" ")}`)
     const app = spawn(cmd, args, { stdio: 'inherit' });
-    app.on('close', resolve);
+    app.on('close', code => {
+        if(code !== 0){
+            err = new Error(`Invalid status code: ${code}`);
+            err.code = code;
+            return reject(err);
+        };
+        return resolve(code);
+    });
     app.on('error', reject);
 });
 
@@ -15,5 +22,5 @@ const main = async () => {
 main().catch(err => {
     console.error(err);
     console.error(err.stack);
-    process.exit(-1);
-})
+    process.exit(err.code || -1);
+})