Jake McCrary

Using lein-test-refresh with expectations

The 2.2.0 release1 of expectations adds a clojure.test compatible syntax. The release adds the defexpect macro which forces you to name your test but then generates code that is compatible with clojure.test.

Why would you want this? Because clojure.test is the built-in testing library for Clojure, an entire ecosystem has been built around it. Tool support for clojure.test is always going to be ahead of support for the original expectations. By using the new clojure.test compatible syntax, expectations can take advantage of all the tools built for clojure.test.

Using lein-test-refresh with expectations

If you move to the new clojure.test compatible syntax, you can start using lein-test-refresh to automatically rerun your tests when your code changes. lein-test-refresh is a fork of the original expectations autorunner, lein-autoexpect, but it has grown to have more features than its original inspiration. Now you can use it with expectations2.

Below is a sample project.clj that uses lein-test-refresh with the latest expectations.

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(defproject expectations-project "0.1.0-SNAPSHOT"
  :description "Sample project using expectations"
  :dependencies [[org.clojure/clojure "1.8.0"]]
  :plugins [[com.jakemccrary/lein-test-refresh  "0.18.1"]]
  :profiles {:dev {:dependencies [[expectations "2.2.0-beta1"]]}})

Here is an example test file.

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(ns expectations-project.core-test
  (:require [expectations :refer :all]
            [expectations.clojure.test :refer [defexpect]]))

(defexpect two
  2 (+ 1 1))

(defexpect three
  3 (+ 1 1))

(defexpect group
  (expect [1 2] (conj [] 1 5))
  (expect #{1 2} (conj #{} 1 2))
  (expect {1 2} (assoc {} 1 3)))

And here is the result of running lein test-refresh.

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$ lein test-refresh
*********************************************
*************** Running tests ***************
:reloading (expectations-project.core-test)

FAIL in (group) (expectations_project/core_test.clj:11)
expected: [1 2]
  actual: [1 5] from (conj [] 1 5)

FAIL in (group) (expectations_project/core_test.clj:11)
expected: {1 2}
  actual: {1 3} from (assoc {} 1 3)

FAIL in (three) (expectations_project/core_test.clj:8)
expected: 3
  actual: 2 from (+ 1 1)

Ran 3 tests containing 5 assertions.n
3 failures, 0 errors.

Failed 3 of 5 assertions
Finished at 11:53:06.281 (run time: 0.270s)

After some quick edits to fix the test errors and saving the file, here is the output from the tests re-running.

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*********************************************
*************** Running tests ***************
:reloading (expectations-project.core-test)

Ran 3 tests containing 5 assertions.
0 failures, 0 errors.
:reloading ()

Ran 3 tests containing 5 assertions.
0 failures, 0 errors.

Passed all tests
Finished at 11:53:59.045 (run time: 0.013s)

If you’re using expectations and switch to the new clojure.test compatible syntax, I’d encourage you to start using lein-test-refresh.

  1. As of 2016-02-27 2.2.0 isn’t out yet, but 2.2.0-beta1 has been released and has the changes.↩
  2. In fact, you have to use it if you use Leiningen and the new syntax and want your tests to run automatically.↩
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