Christopher Miller

Testing Aspen: Trebble's New API Testing Tool: Is It Worth It?

So this week, Treblle have released a new API Testing Tool. Styled as “Aspen - Your API’s Best Friend”. I couldn’t resist but downloading it and giving it a go.

First Impressions

When I downloaded the app, it was interesting to discover it was just a tiny 18.7Mb! that’s pretty impressive

File Size

Now whilst that is impressive, is it also a potential problem? Does it lack features I need for testing my API? Well, we’re going to find out through this blog post.

When I opened it up for the first time, I was greeted with this screen:

First Load

The beauty of the design certainly strikes me. Simple, clean and dark mode support (YAY!) Does it do light mode? YES IT DOES! But I don’t like light modes personally (many do, nothing wrong with them. Just a personal choice). So this is the last time you’ll see light mode in this post.

First Load - Light Mode

Let’s make our first request and check what we get. For our API, we’re going to use the Poke API. Lets start with a really simple GET from this, by hitting https://pokeapi.co/api/v2/pokemon/25 which should give us back Pikachu. Upon pasting in my URL, I noticed a really cool animation slide into place. We can add parameters to this, as well as headers, and a body (not that a get request requires one)

First Request - Params

First Request - Headers

First Request - Body

For now, we’re going to leave it as is - we can try out params later. I clicked Send, and got a useful “loading” spinner, which is very cool! Now we get back some interesting data here:

  1. The Status Code - Oooh! It’s green! That’s good! We can test some others later.
  2. The time to resolve - again, it gave me a green result! must mean that Aspen thinks its quick
  3. The Size of the response
  4. The Server IP
  5. The body - in a collapsable, really pretty layout.
  6. The body - in raw form
  7. The headers - in a table

I mean, this is pretty useful! And honestly seems really well designed so far.

First Response - Pretty Body

First Response - Raw Body

First Response - Headers

What I also noticed was we have a history on the side. That’s also cool! But there doesn’t seem to be any indication of WHY my time was good at 32ms. I mean, obviously it’s a fast request, but what counts as bad? One other minor (and I do mean minor) niggle is when you collapse the request in pretty form, it’s not shrinking the containing box down to the new content.

My next test was to hit a site that was non-existent, and see what happens. I used https://notasite.google.com - which is a non-existent subdomain. We get a specific response from the service, with no body, headers or anything else:

Invalid Site

That’s not what I expected, but is actually better in my opinion! this is a genuine “I don’t exist” response from the HTTP service, so why would it show me headers, content etc!

Let’s try something else: I’m going to try a site that will return some error codes on request: https://httpstat.us

OK - so now this is interesting! the response isn’t from an API, but from a web service, so is in fact HTML response:

firstly, we hit https://httpstat.us/200

HTTP Stat - 200 Response

as you can see, we get no “pretty” body, but do we get raw? YES! ok that’s good :) what I do immediately notice is the red warning on the time - telling me that’s a slow request, which really really useful. Nothing tells me what the boundaries are, but it also doesn’t scream as a problem it’s not there

Delving Deeper: Customising a request

What I’d like to start doing now is customising my request a little bit - I’m going to start by customising the headers for a httpstat.us/200 request I noticed a cool little feature when I started typing - autocomplete dropdowns with some common headers. What I really liked here is the way that the App gives you hints, but doesn’t force you to use that - so what if I want a header called “accept-a-pint” I should be allowed to! and Aspen lets me do that in my requests, but still helpfully suggests options in the dropdown.

HTTP Stat - Auto Complete Dropdown

now what if I changed my status code? Apparently HTTPStat allows that - so lets try a new code. I’m going to try a redirect URL: httpstat.us/301

Interestingly, aspen returns A 200 status code. Interesting! is that correct? a small test with Rest Test Test confirms this, so not an issue in Aspen.

HTTP Stat - 200 Response on 301 Request

OK, let’s make sure we can handle some other codes - let’s try a 422 request. Hitting httpstat.us/402 (with the accept application/json). and look at this! it combines all of the things we’ve seen up to now.

HTTP Stat - 422 Request

Speaking of those status codes and found a really nifty little feature. What if you don’t remember what “422” means? Well - Aspen tells you!

Hovering A Status Code

Lets Do A Post Request

We’re going to test some of the other types of request with JSON Placeholder. Whilst setting this up - I don’t know why I’m surprised by now, but look at this BEAUTIFUL design:

Selecting A Method

Anyway, I Digress. Let’s set up our body. for now our Header is Accept application/json. I went over to the Body tab, and wanted to start writing some JSON. that wasn’t possible, but we can do form data, and the JSON header. interesting!

Body - No JSON Option

What if we make this to a site that can echo back our post data - just to check what we get? right - so we have an interesting missing piece of the jigsaw here: I can’t post JSON!

HTTPBin Echo’s back

A Couple More Things

So whilst browsing around, I noticed in some cases I had tabs. That’s a really useful feature. what I had to do to get them to show up was select a request from the sidebar initially. But then I noticed the + button at the top (how did I miss that?) which is really useful. I can make a couple of different requests, and quickly shift between them. Another feature I like is the history on the right.

What About That Icon In The Corner?

All throughout this we had an icon in the corner. Well, I clicked it! and WOW! integration with Treblle’s Alfred! now this is cool!

Alfred

It’s giving me some prompts at the top of what I might want to do. Using HTTP Bin, I am going to try out the code generation:

Alfred Alfred Alfred Alfred Alfred Alfred Alfred

My Final Thoughts

So for me, this is a great start for quick testing of API’s, with a few minor niggles right now. As new features are added, this will become even better!