package alcotest

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package alcotest
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A lightweight and colourful test framework.

Alcotest provides a simple interface to perform unit tests. It exposes a simple TESTABLE module type, a check function to assert test predicates and a run function to perform a list of unit -> unit test callbacks.

From these descriptions, Alcotest builds a quiet and colorful output where only faulty runs are fully displayed at the end of the run (with the full logs ready to inspect), with a simple (yet expressive) query language to select the tests to run.

Release 0.7.2

type speed_level = [
  1. | `Quick
  2. | `Slow
]

Speed level for a test.

type test_case = string * speed_level * (unit -> unit)

A test case is an UTF-8 encoded documentation string, a speed level and a function to execute.

type test = string * test_case list

A test is an US-ASCII encoded name and a list of test cases.

exception Test_error

The exception return by run in case of errors.

val run : ?and_exit:bool -> ?argv:string array -> string -> test list -> unit

run n t runs the test suite t. n is is the name of the tested library. The optional argument and_exit controls what happens when the function ends. By default, and_exit is set, which makes the function exit with 0 if everything is fine or 1 if there is an issue. If and_exit is false, then the function raises Test_error on error. The optional argument argv specifies the argument sent to alcotest like "--json", "--verbose", etc. (at least one argument is required).

Assert functions

module type TESTABLE = sig ... end

TESTABLE provides an abstract description for testable values.

type 'a testable = (module TESTABLE with type t = 'a)

The type for testable values.

val testable : 'a Fmt.t -> ('a -> 'a -> bool) -> 'a testable

testable pp eq is a new testable with the pretty-printer pp and equality eq.

val pp : 'a testable -> 'a Fmt.t

pp t is t's pretty-printer.

val equal : 'a testable -> 'a -> 'a -> bool
val bool : bool testable

bool tests booleans.

val int : int testable

int tests integers.

val int32 : int32 testable

int32 tests 32-bit integers.

val int64 : int64 testable

int64 tests 64-bit integers.

val float : float testable

float tests floats.

val char : char testable

char tests characters.

val string : string testable

string tests OCaml strings.

val unit : unit testable

unit tests unit values (useful for functions with side-effects).

val list : 'a testable -> 'a list testable

list t tests lists of ts.

val slist : 'a testable -> ('a -> 'a -> int) -> 'a list testable

slist t comp tests sorted lists of ts. The list are sorted using comp.

val array : 'a testable -> 'a array testable

array t tests arrays of ts.

val option : 'a testable -> 'a option testable

option t tests optional ts.

val result : 'a testable -> 'e testable -> ('a, 'e) Result.result testable

result t e tests ts on success and es on failure.

val pair : 'a testable -> 'b testable -> ('a * 'b) testable

pair a b tests pairs of as and bs.

val of_pp : 'a Fmt.t -> 'a testable

of_pp pp tests values which can be printed using pp and compared using Pervasives.compare

val pass : 'a testable

pass tests values of any type and always succeeds.

val reject : 'a testable

reject tests values of any type and always fails.

val check : 'a testable -> string -> 'a -> 'a -> unit

Check that two values are equal.

val fail : string -> 'a

Simply fail.

val check_raises : string -> exn -> (unit -> unit) -> unit

Check that an exception is raised.

Deprecated

val line : Pervasives.out_channel -> ?color:[ `Blue | `Yellow ] -> char -> unit
  • deprecated

    You should write your own line function. For instance:

    let line ppf ?color c =
  let line = String.v ~len:terminal_columns (fun _ -> c) in
  match color with
  | Some c -> Fmt.pf ppf "%a\n%!" Fmt.(styled c string)  line
  | None   -> Fmt.pf ppf "%s\n%!"line