Clojure for Beginners: Clojure Testing with clojure.test — deftest, is, testing, from REPL to CI

Clojure Testing with clojure.test — deftest, is, testing, from REPL to CI

Tests you can run in seconds are tests you'll actually run. In this episode we pin down the `app.util` namespace from Episode 20 — `shout`, `slugify`, `wrap` — with real `clojure.test` assertions. Three `deftest` blocks, seven `is` assertions, and both ways to run them: from the REPL with `run-tests`, and from the command line with `clj -M:test`.

Test Code

(ns app.util-test
  (:require [clojure.test :refer [deftest is testing]]
            [app.util :as u]))

(deftest shout-test
  (testing "uppercases and appends a bang"
    (is (= "HI!" (u/shout "hi")))
    (is (= "HELLO WORLD!" (u/shout "hello world")))))

(deftest slugify-test
  (testing "lowercase, trim, replace spaces, strip punctuation"
    (is (= "hello-world"     (u/slugify "Hello World")))
    (is (= "hello-world"     (u/slugify "  Hello,  World!  ")))
    (is (= "the-little-schemer" (u/slugify "The Little Schemer")))))

(deftest wrap-test
  (testing "wraps with the same character on both sides"
    (is (= "*hi*" (u/wrap "*" "hi")))
    (is (= "|a|"  (u/wrap "|" "a")))))

Key Points

Watch the video above for a full walkthrough — every keystroke is shown so you can code along.

Student code: GitHub