lein-test-partition

Easily partition your clojure.test test suite across multiple JVMs.

Use case

You have a large test suite that take a long time to run - for example, your suite involves UI tests (using selenium, perhaps). Most CI tools support parallelisation within a build pipeline.

lein-test-partition allows you to partition your test suite to run across multiple parallel nodes.

Usage

Put into the :plugins vector of your project.clj.

When running tests using lein-test-partition, specify the total number of partitions, and the partition number to execute. Note: you would use this instead of your regular test runner command (e.g. lein test)

lein-test-partition supports two different strategies for partitioning your suite.

By individual test (deftest) part-tests

Tests are logically grouped together by the hash of the resolved test identifier (i.e. namespace/test-symbol). Best strategy to use to achieve a more even spread of tests across nodes.

By namespace part-ns

All tests within the same namespace are grouped and executed together on the same node. Best strategy to use if a namespace has expensive :all fixtures.

Examples

Split your tests by namespace across 2 build nodes.

# On node 1:
$ lein test-partition part-ns :part 1 :of 2

# on node 2:
$ lein test-partition part-ns :part 2 :of 2

Split all your tests, across 4 build nodes

# On node 1:
$ lein test-partition part-tests :part 1 :of 4

# on node 2:
$ lein test-partition part-tests :part 2 :of 4

# on node 3:
$ lein test-partition part-tests :part 3 :of 4

# on node 4:
$ lein test-partition part-tests :part 4 :of 4

Notes

Test selectors

lein-test-partition honours leiningen's test selectors.

# On node 1:
$ lein test-partition part-tests :part 1 :of 2 :integration

# on node 2:
$ lein test-partition part-tests :part 2 :of 2 :integration

Using other clojure.test runners/plugins

You can use lein-test-partition with any leiningen test runner plugin as long as it supports whitelisting tests using the :only option. This is possible by simply adding a command :alias to your leiningen project.clj.

For example, to use test2junit:

In project.clj, (perhaps in your CI profile):

...
:aliases  {"test" ["test2junit"]}
...

License

Copyright © 2017 ICM Consulting

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.