Im trying to integrate SailsJS with synchronize, which is based on fibers.
http://alexeypetrushin.github.io/synchronize/docs/index.html
As commented on other fiber libraries, I added a custom middleware to create a new fiber per the request.
var sync = require('synchronize');
...
...
sincronized: function (req, res, next) {
sync.fiber(next);
}
The middleware is executing I can confirm via a console.
But then when I try to do anything fiber related, such as sync.defer() in one of my controllers, I do get an exception.
error: Error getting xxxxxx Error: no current Fiber, defer can't be used without Fiber!
As sailsjs is based in express, adding this middleware should be enough, although I have no idea what I might be missing.
As a side comment, if I create a fiber inside the controller method itself, everything works as expected.
Thanks.
Related
So I did a lot of digging around the internet, and I have been unable to come up with the answer to my problem. My goal is that I want to print any errors that are logged to the console into a database. However, I have gone far enough into my project that it would be a pain to go back into my try...catch... blocks and edit them with an error extender, or to just create my own function in the catch area.
I wanted to know: is there a specific way to create an error interception in NodeJS? I mean, I assume that whenever an error is logged to the console, the code fires some sort of event, and I guess I am looking for something like:
process.on(error, async (e) => { // my code here })
Is that at all possible? Is there a module that will allow me to do this? For context, I am running the latest version of Node/NPM on a headless Ubuntu 18.04 server, and am using pm2 to control my program processes.
You can use middleware at the end of the main file of your app
var bodyParser = require('body-parser');
app.use(bodyParser());
...
...
app.use(function(err, req, res, next) {
// Error handler logic
});
You can find more about this in the express documentation https://expressjs.com/en/guide/error-handling.html
I want to extend this open topic: Add Routes at Runtime (ExpressJs) which sadly didn't help me enough.
I'm working on an application that allows the creation of different API's that runs on NodeJs. The UI looks like this:
As you can see, this piece of code contains two endpoints (GET, POST) and as soon as I press "Save", it creates a .js file located in a path where the Nodejs application is looking for its endpoints (e.g: myProject\dynamicRoutes\rule_test.js).
The problem that I have is that being that the Nodejs server is running while I'm developing the code, I'm not able to invoke these new endpoints unless I restart the server once again (and ExpressJs detects the file).
Is there a way to register new routes while the
NodeJs (ExpressJs) is running?
I tried to do the following things with no luck:
app.js
This works if the server is restarted. I tried to include this library (express-dynamic-router, but not working at runtime.)
//this is dynamic routing function
function handleDynamicRoutes(req,res,next) {
var path = req.path; //http://localhost:8080/api/rule_test
//LoadModules(path)
var controllerPath = path.replace("/api/", "./dynamicRoutes/");
var dynamicController = require(controllerPath);
dynamicRouter.index(dynamicController[req.method]).register(app);
dynamicController[req.method] = function(req, res) {
//invocation
}
next();
}
app.all('*', handleDynamicRoutes);
Finally, I readed this article (#NodeJS / #ExpressJS: Adding routes dynamically at runtime), but I couldn't figure out how this can help me.
I believe that this could be possible somehow, but I feel a bit lost. Anyone knows how can I achieve this? I'm getting a CANNOT GET error, after each file creation.
Disclaimer: please know that it is considered as bad design in terms of stability and security to allow the user or even administrator to inject executable code via web forms. Treat this thread as academic discussion and don't use this code in production!
Look at this simple example which adds new route in runtime:
app.get('/subpage', (req, res) => res.send('Hello subpage'))
So basically new route is being registered when app.get is called, no need to walk through routes directory.
All you need to do is simply load your newly created module and pass your app to module.exports function to register new routes. I guess this one-liner should work just fine (not tested):
require('path/to/new/module')(app)
Is req.params enough for you?
app.get('/basebath/:path, (req,res) => {
const content = require('content/' + req.params.path);
res.send(content);
});
So the user can enter whatever after /basepath, for example
http://www.mywebsite.com/basepath/bergur
The router would then try to get the file content/bergur.js
and send it's contents.
I have to test for server errors (Express) in acceptance tests that can't (or shouldn't) be sent with response, for example
Error: Can't set headers after they are sent.
Catching an error with error handler and responding with 5XX code would provide valuable feedback here, but the problem is that the headers have been sent already.
This kind of bugs may be noncritical and hard to spot, and usually they are figured out from the logs.
The spec is
it('should send 200', function (done) {
request(app).get('/').expect(200, done);
});
And tested app is
app.get('/', function (req, res, next) {
res.sendStatus(200);
next();
});
app.use(function (req, res) {
res.sendStatus(200);
});
What is the most appropriate way to communicate between Express app instance and request testing library (i.e. Supertest) in similar cases?
The question is not restricted to Supertest. If there are packages that can solve the problem that Supertest can't, they may be considered as well.
Try to just set the status code without send it and avoid send it twice throwing the error use res.status().
As the express documentation say it
Sets the HTTP status for the response. It is a chainable alias of
Node’s response.statusCode.
IMHO if you want to detect it in a end-to-end (E2E) testing tool like supertest (or Selenium) you have to handle the express error and send a correct output (500 status error, some message...) to permit detect it.
Or use instead a unit test, to test that the controller function doesn't throw any error using chai or a native assertion.
I answered a similar question here. The "can't set headers after they have been set" error should be raised by express as an unhandled exception. So, you should be able to get access to it via the unhandledException event that is raised by the process.
However, this is much more tricky because of the timing. Your test case's expect function and done function will be queued for processing on the event loop on the tick right after the first res.statusCode call. Unfortunately, the next call for res.statusCode can happen at an indeterminate amount of time afterwards. For example, what if the second route handler called a really slow webservice or db and then called res.statusCode.
With that in mind, your options are pretty hard. The brute force way is to wait in your test code for a determinate amount of time and then check. It's effective but slow and non-deterministic, which will cause your test to be flaky.
Another option is to check any instrumentation code that you might have in express. If you have code in express that keeps metrics of the number of in process calls for the various route handlers you could expose these metrics to your test code. Then one of your conditions for finishing your test is that all metrics for in process route calls are 0. The second option would allow you to write deterministic tests and be much faster because you could poll the metrics.
The final option would be to handle this test case through unit tests. This is probably the best solution because it would be deterministic and wouldn't require any sort of polling. However, the downside is that you need to know that both of your functions are called in order which leads you down a path of trying to recreate in your test code the logic that express uses to call route handlers.
I did this using HAPI instead of Express, but I solved the same problem. I used an external library to make the call (like request-promise) and it worked. Catch the error in the request-promise response.
I need to monitor my application's uptime via New Relic. I'm using the Restify framework which is largely based on Express.
New Relic wants to make HEAD requests to my application, but I'm not sure how to set up a HEAD route correctly to satisfy New Relic. Currently, my Restify app returns a 405 error for "Method Not Allowed", which causes New Relic to have fits and send me non-stop emails about how my application is down, and I can't find any documentation from New Relic that shows how to set up a simple ping URL to satisfy them.
Is there anything I need to do other than this:
server.head('/ping', function(error, req, res) {
res.send("hello");
});
EDIT:
The parameters are mislabeled so the res.send() is actually trying to call next().send() which would be undefined. Removing the error parameter and shifting everything over fixed the code as discovered by the OP.
As per the restify documentation, you need to call return next() in your callback function:
http://mcavage.me/node-restify/#Routing
server.head('/ping', function (req, res) {
res.send('hello');
});
If you would like to respond immediately and not continue down the chain, you can pass false as a parameter in your call to next()
I'm new to Node and Sails and have been struggling with this problem for a couple of weeks now. I need to log (eventually to a file or database) all errors that occur in our Sails app. I have found a couple of answers that come close to solving this, but none seem to work 100%. I have setup things based off of the answer from this question
When using Sails v0.9.16 I setup my logging in the config/500.js file, but when using test code...
t.t;
... in my controller, Sails just prints out "ReferenceError: t is not defined". It never goes to 500.js. In Sails v0.10.0-rc5 the same test code will get to my custom 500 middleware (shown below).
Problem is in Sails v0.10.0-rc5 it appears that the middleware Router handles 400 error message before getting to my custom 400 middleware.
We have not committed to which version we are going to use, but getting this to work in one or the other would probably make up our minds.
So how do I get all errors that happen? If I am on the right track, what am I missing to get this to work?
Thanks in advance!
Not much code to show for v0.9.16...I don't think I changed anything other than adding a sails.log in the 500.js file...
Below is the custom middleware setup for v0.10.0-rc5 ...
loadMiddleware: function(app, defaultMiddleware, sails) {
// Use the middleware in the correct order
app.use(defaultMiddleware.startRequestTimer);
app.use(defaultMiddleware.cookieParser);
app.use(defaultMiddleware.session);
app.use(defaultMiddleware.bodyParser);
app.use(defaultMiddleware.handleBodyParserError);
app.use(defaultMiddleware.methodOverride);
app.use(defaultMiddleware.poweredBy);
app.use(defaultMiddleware.router); //400s do not make it past this...
app.use(defaultMiddleware.www);
app.use(defaultMiddleware.favicon);
app.use(function(req, res, next ) {
sails.log("400 error caught in middleware - " + err.stack);
next();
});
app.use(function(err, req, res, next){
sails.log("500 error caught in middleware - " + err.stack);
next(err);
});
}
In Sails v0.10, you have custom responses to handle errors, so you don't need to provide custom middleware as in your example. By default, most errors (i.e. those not specifically triggered by res.forbidden(), res.notFound() or another handler) will be served by the serverError response that lives in api/responses/serverError.js. You can customize this to do whatever you like.
If you've upgraded a v0.9 app to v0.10, you might not have the api/responses folder. No problem; just use sails new whatever in an empty directory to generate a new v0.10 project and copy the api/responses folder from the new project to your old one!