Cognitect Labs Test Runner

test-runner is a test runner for Clojure projects defined with deps.edn and using clojure.test library which is part of the Clojure standard library.

test-runner aims to provide a standard way to discover and run unit and property-based tests, in a simple to use and lightweight tool.

Adding test-runner

Make test-runner available to all projects by adding it to ~/.clojure/deps.edn. Or add test-runner to specific projects by adding an alias to the project deps.edn file. Include :extra-paths configuration to include the standard test directory so that the runner has access to the test code.

:test-runner-cognitect
  {:extra-paths ["test"]
   :extra-deps  {com.cognitect/test-runner
                 {:git/url "https://github.com/cognitect-labs/test-runner.git"
                  :sha     "f7ef16dc3b8332b0d77bc0274578ad5270fbfedd"}}
   :main-opts   ["-m" "cognitect.test-runner"]}

Use practicalli/clojure-deps-edn to add common tools

Fork and clone the practicalli/clojure-deps-edn GitHub repository to instantly have access to dozens of tools for Clojure software development

Running the test runner

Then, invoke Clojure via the command line, invoking the test alias:

clojure -M:test-runner-cognitect

This calls the cognitect.test-runner/-main function which will scan the test directory of the current project for any tests defined using clojure.test and then run all the tests found.

A summary is returned with the results of running the tests.

TODO: screenshot of summary

Additional command line options:

Flag	Description
-d, --dir DIRNAME	Name of the directory containing tests. Defaults to "test".
-n, --namespace SYMBOL	Symbol indicating a specific namespace to test.
-r, --namespace-regex REGEX	Regex for namespaces to test. Defaults to #".*-test$"
	(i.e, only namespaces ending in '-test' are evaluated)
-v, --var SYMBOL	Symbol indicating the fully qualified name of a specific test.
-i, --include KEYWORD	Run only tests that have this metadata keyword.
-e, --exclude KEYWORD	Exclude tests with this metadata keyword.
-H, --test-help	Display this help message

Options can be used multiple times in one command, for a logical OR effect. For example, the following command runs all tests in the practicalli.data.survey and practicalli.services.survey-report namespaces that are found in the src and test directories

clojure -M:test-runner-cognitect -d test -d src -n practicalli.data.survey -n practicalli.services.survey-report

Categorizing tests for selective test runs

Integration tests tend to take longer to run as they use larger data sets and/run a or more comprehensive set of tests. Categorizing tests is an approach to using test runners effectively, by selectively running tests at different stages of development.

Use Clojure metadata when defining test functions using deftest.

(deftest ^:integration test-live-system
  (is (= 200 (:status (http/get "http://example.com")))))

Use the i inclusion flag with the test runner to specify specific categories of tests

clojure -M:test-runner-cognitect -i :integration

Categories can be used together by using multiple flags. Assuming categories of develop, uat, integration and pre-prod, use two -i inclusion flags to run only integration and pre-production tests:

clojure -M:test-runner-cognitect -i :integration -i :pre-prod

Clojure Unit Test - categories example integration and develop tests

Use the e exclusion flag to run all tests except those in specific categories

clojure -M:test-runner-cognitect -e :integration

Exclusions take priority over inclusions if both flags are included.

Category examples

On larger projects categories reduce the amount of time spent running tests to ensure regressions have not taken place.

During a project at a large financial institution, tests were organised in the following categories :develop, :integration, data-loading, :data-migration, and :pre-production.

Cognitect-labs