Test driven clojure part V

We now have passing tests, but our website isn’t very functional. Lets add a home page for our (soon to be) millions of visitors.

Writing our first Joodo-based test

Lets write a test that makes sure that we get a 200 response back from the server when we acsess the root path.

(it "displays a homepage"
  (let [response (do-get "/")]
    (should= 200 (:status response))))

do-get is a method given to us by the joodo.spec-helper.controller namespace. It sends an imaginary post to the path, and seconds the result. The result is a hash-map of {:status ..., :headers ..., :body ...}.

Running this test, we get our next error. Yay!

.F

Failures:

  1) Katchie displays a homepage
     Attempting to call unbound fn: #'joodo.spec-helpers.controller/*routes*

What does this mean? Its our most un-helpful message yet. The problem is that the do-get method doesn’t know what Joodo controller to test. The joodo spec-helpers gives us a message that will point our tests to the right location.

(with-routes app-handler)

Adding that line to our tests will tell Joodo to use the app-handler. Unfortunately we haven’t built a app handler yet and we get another error.

java.lang.RuntimeException: Unable to resolve symbol: app-handler in this context

Lets create that handler in our core.clj file.

(ns katchie.core)

(def app-handler)

Running again we get another error. Remember whenever the message we get back changes, we’re making progress.

Attempting to call unbound fn: #'katchie.core/app-handler

Looks like app-hander is meant to be a function. Lets change the definition of app-hander to reflect that.

(ns katchie.core)

(defn app-handler [])

lein spec gives us our next error.

Wrong number of args (1) passed to: core$app-handler

Great! Now we know that our app-handler has to take an argument. We don’t know what that argument is yet, but we’re slowly learning about Joodo and how it works. Lets rewrite our app-hander method to take that argument then print it out to the console.

(ns katchie.core)

(defn app-handler [thing]
  (println thing))

$ lein spec
.{:request-method :get, :uri /}
F

Failures:

  1) Katchie displays a homepage
     Expected: <200>
          got: nil (using =)

We’ve now discovered the last two pieces of information we need to realize how Joodo works. The first is obvious, the argument we receive is the request hash-map. Is has a :request-method key and a :uri key. The second piece of information we’ve gathered is more hidden. Joodo expects this method to return a response hash. The test is currently calling (:status nil) which returns nil.

One more rewrite of our core.clj file is all we need to get this test to pass.

(ns katchie.core)

(defn app-handler [request]
  {:status 200, :headers {}, :body "Hello World!"})

..

Finished in 0.00065 seconds
2 examples, 0 failures

Perfect we’ve gotten our test to pass and written just enough code to have a fully working Joodo application. We can test it out by running lein joodo server.

After that command you can direct your browser to localhost:8080 and see the fruit of your labor.

HTTP ERROR 500

Problem accessing /. Reason:

    java.lang.RuntimeException: java.io.FileNotFoundException: config/environment.clj (No such file or directory)

Well thats not good. Looks like Joodo was expecting a config/environment.clj file to exist. Lets create that quickly.

;; config/environment.clj
(alter-env! assoc
  :joodo.root.namespace "katchie.core")

This tells Joodo that its root name space is that core file we just created.

HTTP ERROR 500

Problem accessing /. Reason:

    java.lang.RuntimeException: java.io.FileNotFoundException: config/development.clj (No such file or directory)

Well another file missing. Lets create that too.

(alter-env! assoc
  :joodo-env "development"
  :hostname "localhost:8080")

This file sets some global configuration for our development environment. One last time into the breach. Lets start our server and see what we get.

Hello world!

You did it! Congratulations on creating your first Joodo application.