Testing ClojureScript code with cljs.test with phantomjs and figwheel

It isn’t easy to find how-to run tests written with cljs.test, and one of desired ways to run tests — run them from a terminal (or on a ci server). And it’s simple with phantomjs, first of all you need to configure cljsbuild. It config in project.clj should be like:

:cljsbuild {:builds {:test {:source-paths ["src" "test"]
                            :compiler {:output-to "resources/test/compiled.js"
                                       :optimizations :whitespace
                                       :pretty-print true}}}
            :test-commands {"test" ["phantomjs"
                                    ; Files will be crated later:

And fill resources/test/test.js with something like:

var page = require('webpage').create();
var url = phantom.args[0];

page.onConsoleMessage = function (message) {

page.open(url, function (status) {
        // Use your namespace instead of `cljs-test-example`:

Then fill resources/test/test.html with:

<!DOCTYPE html>
    <script src="compiled.js"></script>

And create test.cljs in your tests root with your app namespace instead of cljs-test-example and with run function for running all tests:

(ns cljs-test-example.test
  (:require [cljs.test :refer-macros [run-all-tests]]))


(defn ^:export run
  (run-all-tests #"cljs-test-example.*-test"))

And now you can run your tests:

➜ lein cljsbuild test
Compiling ClojureScript.
Running ClojureScript test: test

Testing cljs-test-example.core-test

Ran 1 tests containing 1 assertions.
0 failures, 0 errors.

Another popular approach is to run tests when source code changed, it can be easily done with figwheel. You just need to configure figwheel to run tests when js loaded:

:cljsbuild {:builds {:main {:source-paths ["src" "test"]
                            ; Runs tests on every change:
                            :figwheel {:on-jsload "cljs-test-example.test/run"}
                            :compiler {:output-to "resources/public/compiled/main.js"
                                       :output-dir "resources/public/compiled"
                                       :asset-path "/compiled"
                                       :main "cljs-test-example.core"
                                       :source-map true
                                       :optimizations :none
                                       :pretty-print false}}}}

Add ^:figwheel-always metadata to the namespace with function for running tests, like:

(ns ^:figwheel-always cljs-test-example.test
  (:require [cljs.test :refer-macros [run-all-tests]]))

And add ^:figwheel-load to all namespaces with tests, like:

(ns ^:figwheel-load cljs-test-example.core-test
  (:require [cljs.test :refer-macros [deftest is]]
            [cljs-test-example.core :refer [do-something-x-y]]))

Then you can see tests results in your browser console, like:

Example project with cljs.test.

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