testgen

A generator for the exercises testsuite

Build

$ make testgen

Run

$ make

Implement a Testgenerator

1. Create a module that is named as the exercise, but prefixed with tgen_.
2. Make it implement the tgen behaviour.

Callbacks

tgen:revision/0

Spec: () -> pos_integer()

When you initially create the module make this return 1, after that every PullRequest changing the module shall also increment the number by 1.

It is the monotonically increasing version of this module.

tgen:generate_test/2

Spec: (non_neg_integer(), exercise_json()) -> {ok, erl_syntax:syntax_tree() | [erl_syntax:syntax_tree()], [{string() | binary(), non_neg_integer()}]} } | ignore

The first argument, usually called N has to be considered opaque, it has to be passed to tgen:to_test_name/2 as first argument to generate the testname.

The second argument is the current JSON blob. Please refer to the actual JSON specification of the exercise.

tgen:prepare_test_module/0 (Optional)

Spec: prepare_test_module() -> {ok, [erl_syntax:syntax_tree()]}

Can inject arbitrary code into the test module, eg. helper functions, macros, etc.

tgen:prepare_tests/1 (Optional)

Spec: prepare_tests([exercise_json()]) -> [exercise_json()]

This callback is called with a list of the JSON as it got parsed, it can be used to enrich the JSON with additional data or to filter some tests out, or even to change order of tests.