Alcotest is a lightweight and colourful test framework
Module type Alcotest_engine . V1 . Core . S
type return

The return type of each test case run by Alcotest. For the standard Alcotest module, return = unit. The concurrent backends Alcotest_lwt and Alcotest_async set return = unit Lwt.t and return = Async_kernel.Deferred.t respectively.

type speed_level = [
| `Quick
| `Slow

Speed level of a test. Tests marked as `Quick are always run. Tests marked as `Slow are skipped when the `-q` flag is passed.

type 'a test_case = string * speed_level * ( 'a -> return )

A test case is a UTF-8 encoded documentation string, a speed level and a function to execute. Typically, the testing function calls the helper functions provided below (such as check and fail).

exception Test_error

The exception return by run in case of errors.

val test_case : string -> speed_level -> ( 'a -> return ) -> 'a test_case

test_case n s f is the test case n running at speed s using the function f.

type 'a test = string * 'a test_case list

A test is a UTF-8 encoded name and a list of test cases. The name can be used for filtering which tests to run on the CLI.

type 'a with_options = ?and_exit:bool -> ?verbose:bool -> ?compact:bool -> ?tail_errors:[ `Unlimited | `Limit of int ] -> ?quick_only:bool -> ?show_errors:bool -> ?json:bool -> ?filter:( name:string -> index:int -> [ `Run | `Skip ] ) -> ?log_dir:string -> ?bail:bool -> ?record_backtrace:bool -> 'a

The various options taken by the tests runners run and run_with_args:

  • and_exit (default true). Once the tests have completed, exit with return code 0 if all tests passed, otherwise 1.
  • verbose (default false). Display the test std.out and std.err (rather than redirecting to a log file).
  • compact (default false). Compact the output of the tests.
  • tail_errors (default unlimited). Show only the last N lines of output of failed tests.
  • quick_only (default false). Don't run tests with the `Slow speed level.
  • show_errors (default false). Display the test errors.
  • json (default false). Print test results in a JSON-compatible format.
  • log_dir (default "$PWD/_build/_tests/"). The directory in which to log the output of the tests (if verbose is not set).
  • bail (default false). If true, stop running the tests after the first failure.
  • record_backtrace (defualt true). Enable backtrace recording before beginning testing.
val run : ( string -> unit test list -> return ) with_options
val run_with_args : ( string -> 'a -> 'a test list -> return ) with_options