Enable express error handler (#4697)

* Propagate error to express handler in all situations

* Call the default error handler if `enableExpressErrorHandler` is truthy

* Updating options interface and definitions

* Testing express error handler

* Test spec fixes

* Fix test

spec/EnableExpressErrorHandler.spec.js

@@ -0,0 +1,66 @@
+const ParseServer = require("../lib/index");
+const express = require('express');
+const rp = require('request-promise');
+
+describe('Enable express error handler', () => {
+
+  it('should call the default handler in case of error, like updating a non existing object', done => {
+    const serverUrl = "http://localhost:12667/parse"
+    const appId = "anOtherTestApp";
+    const masterKey = "anOtherTestMasterKey";
+    let server;
+
+    let lastError;
+
+    const parseServer = ParseServer.ParseServer(Object.assign({},
+      defaultConfiguration, {
+        appId: appId,
+        masterKey: masterKey,
+        serverURL: serverUrl,
+        enableExpressErrorHandler: true,
+        __indexBuildCompletionCallbackForTests: promise => {
+          promise.then(() => {
+            expect(Parse.applicationId).toEqual("anOtherTestApp");
+            const app = express();
+            app.use('/parse', parseServer);
+
+            server = app.listen(12667);
+
+            app.use(function (err, req, res, next) {
+              next;
+              lastError = err;
+            })
+
+            rp({
+              method: 'PUT',
+              uri: serverUrl + '/classes/AnyClass/nonExistingId',
+              headers: {
+                'X-Parse-Application-Id': appId,
+                'X-Parse-Master-Key': masterKey
+              },
+              body: { someField: "blablabla" },
+              json: true
+            }).then(() => {
+              fail('Should throw error');
+            }).catch(e => {
+              expect(e).toBeDefined();
+              const reqError = e.error;
+              expect(reqError).toBeDefined();
+              expect(lastError).toBeDefined();
+
+              expect(lastError.code).toEqual(101)
+              expect(lastError.message).toEqual('Object not found.')
+
+              expect(lastError.code).toEqual(reqError.code);
+              expect(lastError.message).toEqual(reqError.error);
+            }).then(() => {
+              server.close(done);
+            });
+          })
+        }
+      }
+    ));
+  });
+
+});
+

src/Options/Definitions.js

@@ -262,6 +262,12 @@ module.exports.ParseServerOptions = {
     "action": parsers.booleanParser,
     "default": false
   },
+  "enableExpressErrorHandler": {
+    "env": "PARSE_SERVER_ENABLE_EXPRESS_ERROR_HANDLER",
+    "help": "Enables the default express error handler for all errors",
+    "action": parsers.booleanParser,
+    "default": false
+  },
   "objectIdSize": {
     "env": "PARSE_SERVER_OBJECT_ID_SIZE",
     "help": "Sets the number of characters in generated object id's, default 10",

src/Options/index.js

@@ -114,6 +114,8 @@ export interface ParseServerOptions {
   cacheMaxSize : ?number; // = 10000
   /* Use a single schema cache shared across requests. Reduces number of queries made to _SCHEMA. Defaults to false, i.e. unique schema cache per request. */
   enableSingleSchemaCache: ?boolean; // = false
+  /* Enables the default express error handler for all errors */
+  enableExpressErrorHandler: ?boolean; // = false
   /* Sets the number of characters in generated object id's, default 10 */
   objectIdSize: ?number; // = 10
   /* The port to run the ParseServer. defaults to 1337.

src/middlewares.js

@@ -284,6 +284,9 @@ export function handleParseErrors(err, req, res, next) {
     res.status(httpStatus);
     res.json({ code: err.code, error: err.message });
     log.error(err.message, err);
+    if (req.config && req.config.enableExpressErrorHandler) {
+      next(err);
+    }
   } else if (err.status && err.message) {
     res.status(err.status);
     res.json({ error: err.message });