Questions tagged [ounit]

With OUnit, as with JUnit, you can easily create tests, name them, group them into suites, and execute them, with the framework checking the results automatically.

The basic principle of a test suite is to have a file test.ml which will contain the tests, and an OCaml module under test, named foo.ml.

File foo.ml:

(* The functions we wish to test *)
let unity x = x;;
let funix ()= 0;;
let fgeneric () = failwith "Not implemented";;

The main point of a test is to check that the function under test has the expected behavior. You check the behavior using assert functions. The most simple one is OUnit2.assert_equal. This function compares the result of the function with an expected result.

The most useful functions are:

• OUnit2.assert_equal the basic assert function
• OUnit2.(>:::) to define a list of tests
• OUnit2.(>::) to name a test
• OUnit2.run_test_tt_main to run the test suite you define
• OUnit2.bracket_tmpfile that create a temporary filename.
• OUnit2.bracket_tmpdir that create a temporary directory.

File test.ml:

open OUnit2;;

let test1 test_ctxt = assert_equal "x" (Foo.unity "x");;

let test2 test_ctxt = assert_equal 100 (Foo.unity 100);;

(* Name the test cases and group them together *)
let suite =
  "suite">:::
    ["test1">:: test1;
     "test2">:: test2]
;;

let () =
  run_test_tt_main suite
;;

And compile the module

$ ocamlfind ocamlc -o test -package oUnit -linkpkg -g foo.ml test.ml

An executable named "test" will be created. When run it produces the following output:

$ ./tests
..
Ran: 2 tests in: 0.00 Seconds
OK

When using OUnit2.run_test_tt_main, a non zero exit code signals that the test suite was not successful.

(Source)