fix: Throwing error in Cloud Code Triggers afterLogin, afterLogout crashes server (parse-community#8280)

BREAKING CHANGE: Throwing an error in Cloud Code Triggers `afterLogin`, `afterLogout` returns a rejected promise; in previous releases it crashed the server if you did not handle the error on the Node.js process level; consider adapting your code if your app currently handles these errors on the Node.js process level with `process.on('unhandledRejection', ...)`

Author: dblythy

spec/CloudCode.spec.js

@@ -3103,6 +3103,36 @@ describe('beforeLogin hook', () => {
     done();
   });
 
+  it('does not crash server when throwing in afterLogin hook', async () => {
+    const error = new Parse.Error(2000, 'afterLogin error');
+    const trigger = {
+      afterLogin() {
+        throw error;
+      },
+    };
+    const spy = spyOn(trigger, 'afterLogin').and.callThrough();
+    Parse.Cloud.afterLogin(trigger.afterLogin);
+    await Parse.User.signUp('user', 'pass');
+    const response = await Parse.User.logIn('user', 'pass').catch(e => e);
+    expect(spy).toHaveBeenCalled();
+    expect(response).toEqual(error);
+  });
+
+  it('does not crash server when throwing in afterLogout hook', async () => {
+    const error = new Parse.Error(2000, 'afterLogout error');
+    const trigger = {
+      afterLogout() {
+        throw error;
+      },
+    };
+    const spy = spyOn(trigger, 'afterLogout').and.callThrough();
+    Parse.Cloud.afterLogout(trigger.afterLogout);
+    await Parse.User.signUp('user', 'pass');
+    const response = await Parse.User.logOut().catch(e => e);
+    expect(spy).toHaveBeenCalled();
+    expect(response).toEqual(error);
+  });
+
   it('should have expected data in request', async done => {
     Parse.Cloud.beforeLogin(req => {
       expect(req.object).toBeDefined();

src/Routers/UsersRouter.js

@@ -281,7 +281,7 @@ export class UsersRouter extends ClassesRouter {
     await createSession();
 
     const afterLoginUser = Parse.User.fromJSON(Object.assign({ className: '_User' }, user));
-    maybeRunTrigger(
+    await maybeRunTrigger(
       TriggerTypes.afterLogin,
       { ...req.auth, user: afterLoginUser },
       afterLoginUser,
@@ -360,49 +360,36 @@ export class UsersRouter extends ClassesRouter {
       });
   }
 
-  handleLogOut(req) {
+  async handleLogOut(req) {
     const success = { response: {} };
     if (req.info && req.info.sessionToken) {
-      return rest
-        .find(
+      const records = await rest.find(
+        req.config,
+        Auth.master(req.config),
+        '_Session',
+        { sessionToken: req.info.sessionToken },
+        undefined,
+        req.info.clientSDK,
+        req.info.context
+      );
+      if (records.results && records.results.length) {
+        await rest.del(
           req.config,
           Auth.master(req.config),
           '_Session',
-          { sessionToken: req.info.sessionToken },
-          undefined,
-          req.info.clientSDK,
+          records.results[0].objectId,
           req.info.context
-        )
-        .then(records => {
-          if (records.results && records.results.length) {
-            return rest
-              .del(
-                req.config,
-                Auth.master(req.config),
-                '_Session',
-                records.results[0].objectId,
-                req.info.context
-              )
-              .then(() => {
-                this._runAfterLogoutTrigger(req, records.results[0]);
-                return Promise.resolve(success);
-              });
-          }
-          return Promise.resolve(success);
-        });
+        );
+        await maybeRunTrigger(
+          TriggerTypes.afterLogout,
+          req.auth,
+          Parse.Session.fromJSON(Object.assign({ className: '_Session' }, records.results[0])),
+          null,
+          req.config
+        );
+      }
     }
-    return Promise.resolve(success);
-  }
-
-  _runAfterLogoutTrigger(req, session) {
-    // After logout trigger
-    maybeRunTrigger(
-      TriggerTypes.afterLogout,
-      req.auth,
-      Parse.Session.fromJSON(Object.assign({ className: '_Session' }, session)),
-      null,
-      req.config
-    );
+    return success;
   }
 
   _throwOnBadEmailConfig(req) {