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All right.

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And up next, let's discuss async errors.

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How are they different from synchronous errors and what are going to be our approaches to handle them?

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So first, let's navigate to job controller and let's establish that job dot create.

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Effectively is asynchronous.

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So what happens if there's some kind of error?

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So at the moment, yeah, everything is nice.

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We pass in the req.body and we're good to go.

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But what happens, for example, if I pass here the string, the create is looking for object.

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I can tell you that right away.

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But what if I go with something?

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Let's see the result we get.

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So let me navigate to Thunder Client Create job doesn't really matter what you send over here.

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The main point is following notice we'll get this massive error in the console.

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Okay.

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But then our entire application crashed.

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So unlike the previous setup for synchronous errors, yes, we log still the error, but we nicely send

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back the response and also our server is still running.

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So yeah, we handle the error, but then we keep accepting the requests.

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It's not the case right now.

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So pretty much every time we'll have some kind of error happening.

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Well, our whole server is going to go down and of course we want to fix that.

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That's not the application we want.

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And essentially we have two approaches.

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We can set up, try and catch manually, which we're going to do in a second.

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Also, we can install package so that way we don't have to do it pretty much for every controller.

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So let's try the manual approach first.

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So I'm going to go here with try and catch.

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Then let me move these two lines of code up.

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And then as far as the catch one, let's just send something generic.

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I'm going to go with status 500.

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That.

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And we're going to go with Jason.

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And let's go with message and server.

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Error.

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Let's save it.

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And now let's try it out one more time.

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So let me send and check it out.

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We get back the 500 response.

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Message server error.

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And since we are working with Morgan, we can also see in the console that we made a post request and

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the response is 500.

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But the main point here is that our server is still running.

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So I can go to, for example, get all jobs and yes, of course I'll get those hardcoded jobs, but

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everything still works.

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This is still 200.

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Now if we want to log the error again, we'll just do it manually for now.

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We'll say over here, log an error and we're pretty much good to go again.

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I'll create the job.

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Yes, I'll get 500.

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Yes, I'll get the log in the console.

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But again, the main point is our server is running.

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Okay.

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Hopefully that is clear.

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So essentially since we're performing asynchronous operation, we want to wrap it in, try and catch.

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But your next question probably is following.

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Okay.

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Does that mean that pretty much we'll have to repeat this logic for every controller?

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And the answer is, well, yes and no.

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Technically, you can do it this way.

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So essentially you set up the try and catch for every controller, which is a little bit annoying,

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especially if you have, I don't know, 30 controllers or we can install a package that effectively

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will do that for us.

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And essentially this is what I'm going to do right now.

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So let's navigate to our read me and let me show you that there is a package by the name of express

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async errors, which essentially just provides that error to our error middleware in the server or here

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because like you just saw, it's not happening by default.

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Now, one last thing that I want to mention.

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Make sure that the import is at the very, very, very top on the server.

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Some students have complained that functionality doesn't work.

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If that's not the case.

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So in order to install this package, you want to go to NPM.

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I then express async errors and this is the version that I'm using.

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And then once you install the package, you want to go with import.

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And notice in this case we have the syntax.

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So import and then pretty much the package name again, please place it at the very top and you'll avoid

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some unnecessary bugs.

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So in here, let's go with import then we're going to go with express async errors.

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Just to stay on the safe side, I'll actually stop my server manually clear everything npm run dev and

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then let's go to create job in the job controller and let's remove those try catches and let's see what

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happens because again, we still have the error.

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This should be an object and I'm actually passing here the string.

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So let me create the job one more time.

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I send and notice my server is still working.

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I'm getting this 500 as far as the response and I also nicely can see my log over here.

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Why?

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Well, because in my error middleware we're logging it right now.

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So essentially the express async errors package.

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Handles any asynchronous errors and passes them to our middleware.

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Since it's not happening by default and since I don't want to type.

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Try and catch for every controller we're about to create.

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Well, that's why we'll use this awesome package.

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Just make sure.

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To place the import at the very, very top in the server.js file.