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Module OUnit2

module OUnit2: sig .. end
Unit test building blocks (v2).
Author(s): Sylvain Le Gall


type test_ctxt = OUnitTest.ctxt 
Context of a test.
type test_fun = test_ctxt -> unit 
The type of test function.
type test = OUnitTest.test 
The type of test.
type test_length = OUnitTest.test_length 
The expected length of the test.


Assertions are the basic building blocks of unittests.

val assert_failure : string -> 'a
Signals a failure. This will raise an exception with the specified string.
Raises Failure signal a failure
val assert_bool : string -> bool -> unit
Signals a failure when bool is false. The string identifies the failure.
Raises Failure signal a failure
val assert_string : string -> unit
Signals a failure when the string is non-empty. The string identifies the failure.
Raises Failure signal a failure
val assert_command : ?exit_code:Unix.process_status ->
?sinput:char Stream.t ->
?foutput:(char Stream.t -> unit) ->
?use_stderr:bool ->
?backtrace:bool ->
?chdir:string ->
?env:string array -> ctxt:test_ctxt -> string -> string list -> unit
assert_command prg args Run the command provided.
exit_code : expected exit code
sinput : provide this char Stream.t as input of the process
foutput : run this function on output, it can contains an assert_equal to check it
use_stderr : redirect stderr to stdout
backtrace : Set OCAMLRUNPARAM=b
chdir : Chdir into a directory before running the command.
env : Unix environment
val assert_equal : ?ctxt:test_ctxt ->
?cmp:('a -> 'a -> bool) ->
?printer:('a -> string) ->
?pp_diff:(Format.formatter -> 'a * 'a -> unit) ->
?msg:string -> 'a -> 'a -> unit
assert_equal expected real Compares two values, when they are not equal a failure is signaled.
Raises Failure signal a failure
ctxt : if provided, always print expected and real value
cmp : customize function to compare, default is =
printer : value printer, don't print value otherwise
pp_diff : if not equal, ask a custom display of the difference using diff fmt exp real where fmt is the formatter to use
msg : custom message to identify the failure
val assert_raises : ?msg:string -> exn -> (unit -> 'a) -> unit
Asserts if the expected exception was raised.
Raises Failure description
msg : identify the failure

Skipping tests

In certain condition test can be written but there is no point running it, because they are not significant (missing OS features for example). In this case this is not a failure nor a success. Following functions allow you to escape test, just as assertion but without the same error status.

A test skipped is counted as success. A test todo is counted as failure.

val skip_if : bool -> string -> unit
skip cond msg If cond is true, skip the test for the reason explain in msg. For example skip_if (Sys.os_type = "Win32") "Test a doesn't run on windows".
val todo : string -> unit
The associated test is still to be done, for the reason given.

Compare Functions

val cmp_float : ?epsilon:float -> float -> float -> bool
Compare floats up to a given relative error.
epsilon : if the difference is smaller epsilon values are equal


A bracket is a registered object with setUp and tearDown in unit tests. Data generated during the setUp will be automatically tearDown when the test ends.

val bracket : (test_ctxt -> 'a) ->
('a -> test_ctxt -> unit) -> test_ctxt -> 'a
bracket set_up tear_down test_ctxt set up an object and register it to be tore down in test_ctxt.
val bracket_tmpfile : ?prefix:string ->
?suffix:string ->
?mode:Pervasives.open_flag list ->
test_ctxt -> string * Pervasives.out_channel
bracket_tmpfile test_ctxt Create a temporary filename and matching output channel. The temporary file is removed after the test.
prefix : see Filename.open_temp_file
suffix : see Filename.open_temp_file
mode : see Filename.open_temp_file
val bracket_tmpdir : ?prefix:string -> ?suffix:string -> test_ctxt -> string
bracket_tmpdir test_ctxt Create a temporary dirname. The temporary directory is removed after the test.
prefix : see Filename.open_temp_file
suffix : see Filename.open_temp_file
val with_bracket_chdir : test_ctxt -> string -> (test_ctxt -> 'a) -> 'a
with_bracket_chdir test_ctxt dn f change directory to dn during execution of function f. In order to Sys.chdir, we need to take a lock to avoid other tests trying to do change the current directory at the same time. So this bracket is not directly accessible in order to use it only on shorter piece of code.

Constructing Tests

val (>:) : string -> test -> test
Create a TestLabel for a test
val (>::) : string -> test_fun -> test
Create a TestLabel for a TestCase
val (>:::) : string -> test list -> test
Create a TestLabel for a TestList
val test_case : ?length:test_length -> test_fun -> test
Generic function to create a test case.
val test_list : test list -> test
Generic function to create a test list.

Some shorthands which allows easy test construction.


Performing Tests

type log_severity = [ `Error | `Info | `Warning ] 
Severity level for log.
val logf : test_ctxt ->
log_severity -> ('a, unit, string, unit) Pervasives.format4 -> 'a
Log into OUnit logging system.
val in_testdata_dir : test_ctxt -> string list -> string
Build a filename for a file that should be located in the test data dir.

The test data dir, can be defined on the command line (preferably absolute) The default option is to locate it in topsrcdir/test/data.

val non_fatal : test_ctxt -> (test_ctxt -> unit) -> unit
non_fatal ctxt f Run f but if an exception is raised or an assert fails, don't stop, just register the result. The global test running result will mix in the non fatal result to determine the success or failure of the test.
module Conf: sig .. end
Define command line options, environment variables and file configuration.
val run_test_tt_main : ?exit:(int -> unit) -> test -> unit
Main version of the text based test runner. It reads the supplied command line arguments to set the verbose level and limit the number of test to run.