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module OUnit2

: sig

Unit test building blocks (v2).

Author Sylvain Le Gall

Types

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type test_ctxt = OUnitTest.ctxt

Context of a test.

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type test_fun = test_ctxt -> unit

The type of test function.

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type test = OUnitTest.test

The type of test.

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type test_length = OUnitTest.test_length

The expected length of the test.

Assertions

Assertions are the basic building blocks of unittests.

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val assert_failure : string -> 'a

Signals a failure. This will raise an exception with the specified string.

Raises Failure signal a failure
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val assert_bool : string -> bool -> unit

Signals a failure when bool is false. The string identifies the failure.

Raises Failure signal a failure
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val assert_string : string -> unit

Signals a failure when the string is non-empty. The string identifies the failure.

Raises Failure signal a failure
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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
verbose if a failed, dump stdout/stderr of the process to stderr
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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.

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
ctxt if provided, always print expected and real value
Raises Failure signal a failure
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val assert_raises : ?msg:string -> exn -> (unit -> 'a) -> unit

Asserts if the expected exception was raised.

msg identify the failure
Raises Failure description

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.

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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".

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val todo : string -> unit

The associated test is still to be done, for the reason given.

Compare Functions

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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

Bracket

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.

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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.

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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
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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
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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

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val (>:) : string -> test -> test

Create a TestLabel for a test

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val (>::) : string -> test_fun -> test

Create a TestLabel for a TestCase

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val (>:::) : string -> test list -> test

Create a TestLabel for a TestList

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val test_case : ?length:test_length -> test_fun -> test

Generic function to create a test case.

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val test_list : test list -> test

Generic function to create a test list.

Some shorthands which allows easy test construction.

Examples:

  • "test1" >: TestCase((fun _ -> ())) => TestLabel("test2", TestCase((fun _ -> ())))
  • "test2" >:: (fun _ -> ()) => TestLabel("test2", TestCase((fun _ -> ())))
  • "test-suite" >::: ["test2" >:: (fun _ -> ());] => TestLabel("test-suite", TestSuite([TestLabel("test2", TestCase((fun _ -> ())))]))

Performing Tests

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type log_severity = [
| `Error
| `Warning
| `Info
]

Severity level for log.

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val logf : test_ctxt -> log_severity -> ('a, unit, string, unit) Pervasives.format4 -> 'a

Log into OUnit logging system.

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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.

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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.

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module Conf : sig

Define command line options, environment variables and file configuration.

This module helps to define configuration options that are translated to command line options et al.

The name defined for the variable is:

  • should be a valid OCaml identifier
  • kept as is for use in configuration file. (foo_bar = "")
  • '_' are replaced by '-' and a leading '-' is added for command line (-foo "")
  • capitalized and prefixed by OUNIT_ for environment (OUNIT_FOO_BAR="")
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type 'a conf_t = string -> 'a -> Arg.doc -> test_ctxt -> 'a

The default type of function that create a configuration option of type 'a.

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val make_string : string conf_t

make_string name default help Create a string configuration option with default value default and a short help string. The result of the partial application of the function can be used inside tests to be evaluated to a value.

let my_option = Conf.make_string "my_option" "the default" "A default option."

let tests =
  "ATest" >::
  (fun test_ctxt -> let option_value = my_option test_ctxt in ())
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val make_string_opt : string option conf_t

Create a string option configuration option. See !make_string.

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val make_int : int conf_t

Create an int configuration option. See !make_string.

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val make_float : float conf_t

Create a float configuration option. See !make_string.

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val make_bool : bool conf_t

Create a bool configuration option. See !make_string.

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val make_exec : string -> test_ctxt -> string

make_exec execname Create a option to define an executable.

end
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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.

test the test suite to run.
end