fix(server): don't crash on setupExitSignals(undefined) (#2507)

Author: cben

lib/utils/setupExitSignals.js

@@ -5,7 +5,7 @@ const signals = ['SIGINT', 'SIGTERM'];
 function setupExitSignals(serverData) {
   signals.forEach((signal) => {
     process.on(signal, () => {
-      if (serverData.server) {
+      if (serverData && serverData.server) {
         serverData.server.close(() => {
           // eslint-disable-next-line no-process-exit
           process.exit();

test/server/utils/setupExitSignals.test.js

@@ -25,6 +25,16 @@ describe('setupExitSignals', () => {
   });
 
   signals.forEach((signal) => {
+    it(`should exit process (${signal}, serverData never defined`, (done) => {
+      // eslint-disable-next-line no-undefined
+      setupExitSignals(undefined);
+      process.emit(signal);
+      setTimeout(() => {
+        expect(exitSpy.mock.calls.length).toEqual(1);
+        done();
+      }, 1000);
+    });
+
     it(`should exit process (${signal}, server never defined)`, (done) => {
       setupExitSignals({
         server: null,