fix(techdocs-cli): wait for child process to finish

Signed-off-by: Camila Belo <camilaibs@gmail.com>

packages/techdocs-cli/src/commands/serve/serve.ts

@@ -122,5 +122,10 @@ export default async function serve(cmd: Command) {
       );
     });
 
-  await waitForSignal([mkdocsChildProcess]);
+  try {
+    await waitForSignal([mkdocsChildProcess]);
+    process.exit(0);
+  } catch {
+    process.exit(1);
+  }
 }

packages/techdocs-cli/src/e2e.test.ts

@@ -56,13 +56,10 @@ describe('end-to-end', () => {
 
   it('can serve in backstage', async () => {
     jest.setTimeout(10000);
-    const proc = await executeTechDocsCliCommand(
-      ['serve', '--no-docker', '--mkdocs-port=8888'],
-      {
-        cwd: FIXTURE_DIR,
-        killAfter: 8000,
-      },
-    );
+    const proc = await executeTechDocsCliCommand(['serve', '--no-docker'], {
+      cwd: FIXTURE_DIR,
+      killAfter: 8000,
+    });
 
     expect(proc.combinedStdOutErr).toContain('Starting mkdocs server');
     expect(proc.combinedStdOutErr).toContain('Serving docs in Backstage at');

packages/techdocs-cli/src/lib/run.ts

@@ -49,7 +49,6 @@ export const run = async (
 
   const childProcess = spawn(name, args, {
     stdio: stdio,
-    shell: true,
     ...options,
     env,
   });
@@ -72,6 +71,14 @@ export async function waitForSignal(
 ): Promise<void> {
   const promises: Array<Promise<void>> = [];
 
+  for (const signal of ['SIGINT', 'SIGTERM'] as const) {
+    process.on(signal, () => {
+      childProcesses.forEach(childProcess => {
+        childProcess.kill();
+      });
+    });
+  }
+
   childProcesses.forEach(childProcess => {
     if (typeof childProcess.exitCode === 'number') {
       if (childProcess.exitCode) {
@@ -80,24 +87,10 @@ export async function waitForSignal(
       return;
     }
 
-    for (const signal of ['SIGINT', 'SIGTERM'] as const) {
-      process.on(signal, () => {
-        childProcess.kill(signal);
-        // exit instead of resolve. The process is shutting down and resolving a promise here logs an error
-        process.exit();
-      });
-    }
-
     promises.push(
       new Promise<void>((resolve, reject) => {
-        childProcess.once('error', error => reject(error));
-        childProcess.once('exit', code => {
-          if (code) {
-            reject(new Error(`Non zero exit code from child process`));
-          } else {
-            resolve();
-          }
-        });
+        childProcess.once('error', reject);
+        childProcess.once('exit', resolve);
       }),
     );
   });