NAME

libtap - Write tests in C

SYNOPSIS

#include <tap.h>

int main () {
    plan(5);
    int bronze = 1, silver = 2, gold = 3;
    ok(bronze < silver, "bronze is less than silver");
    ok(bronze > silver, "not quite");
    is("gold", "gold", "gold is gold");
    cmp_ok(silver, "<", gold, "%d <= %d", silver, gold);
    like("platinum", ".*inum", "platinum matches .*inum");
    done_testing();
}

results in:

1..5
ok 1 - bronze is less than silver
not ok 2 - not quite
#   Failed test 'not quite'
#   at t/synopsis.c line 7.
ok 3 - gold is gold
ok 4 - 2 <= 3
ok 5 - platinum matches .*inum
# Looks like you failed 1 test of 5 run.

DESCRIPTION

tap is an easy to read and easy to write way of creating tests for your software. This library creates functions that can be used to generate it for your C programs. It is implemented using macros that include file and line info automatically, and makes it so that the format message of each test is optional. It is mostly based on the Test::More Perl module.

INSTALL

On Unix systems:

$ make
$ make install

For more detailed installation instructions (eg, for Windows), see INSTALL.

FUNCTIONS

• plan(tests)

• plan(NO_PLAN)

• plan(SKIP_ALL);

• plan(SKIP_ALL, fmt, ...)

  Use this to start a series of tests. When you know how many tests there will be, you can put a number as a number of tests you expect to run. If you do not know how many tests there will be, you can use plan(NO_PLAN) or not call this function. When you pass it a number of tests to run, a message similar to the following will appear in the output:

  1..5
  

  If you pass it SKIP_ALL, the whole test will be skipped.

• ok(test)

• ok(test, fmt, ...)

  Specify a test. the test can be any statement returning a true or false value. You may optionally pass a format string describing the test.

  ok(r = reader_new("Of Mice and Men"), "create a new reader");
  ok(reader_go_to_page(r, 55), "can turn the page");
  ok(r->page == 55, "page turned to the right one");
  

  Should print out:

  ok 1 - create a new reader
  ok 2 - can turn the page
  ok 3 - page turned to the right one
  

  On failure, a diagnostic message will be printed out.

  not ok 3 - page turned to the right one
  #   Failed test 'page turned to the right one'
  #   at reader.c line 13.
  

• is(got, expected)

• is(got, expected, fmt, ...)

• isnt(got, unexpected)

• isnt(got, unexpected, fmt, ...)

  Tests that the string you got is what you expected. with isnt, it is the reverse.

  is("this", "that", "this is that");
  

  prints:

  not ok 1 - this is that
  #   Failed test 'this is that'
  #   at is.c line 6.
  #          got: 'this'
  #     expected: 'that'
  

• cmp_ok(a, op, b)

• cmp_ok(a, op, b, fmt, ...)

  Compares two ints with any binary operator that doesn't require an lvalue. This is nice to use since it provides a better error message than an equivalent ok.

  cmp_ok(420, ">", 666);
  

  prints:

  not ok 1
  #   Failed test at cmpok.c line 5.
  #     420
  #         >
  #     666
  

• cmp_mem(got, expected, n)

• cmp_mem(got, expected, n, fmt, ...)

  Tests that the first n bytes of the memory you got is what you expected. NULL pointers for got and expected are handled (if either is NULL, the test fails), but you need to ensure n is not too large.

  char *a = "foo";
  char *b = "bar";
  cmp_mem(a, b, 3)
  

  prints

  not ok 1
  #   Failed test at t/cmp_mem.c line 9.
  #     Difference starts at offset 0
  #          got: 0x66
  #     expected: 0x62
  

• like(got, expected)

• like(got, expected, fmt, ...)

• unlike(got, unexpected)

• unlike(got, unexpected, fmt, ...)

  Tests that the string you got matches the expected extended POSIX regex. unlike is the reverse. These macros are the equivalent of a skip on Windows.

  like("stranger", "^s.(r).*\\1$", "matches the regex");
  

  prints:

  ok 1 - matches the regex
  

• pass()

• pass(fmt, ...)

• fail()

• fail(fmt, ...)

  Speciy that a test succeeded or failed. Use these when the statement is longer than you can fit into the argument given to an ok() test.

• dies_ok(code)

• dies_ok(code, fmt, ...)

• lives_ok(code)

• lives_ok(code, fmt, ...)

  Tests whether the given code causes your program to exit. The code gets passed to a macro that will test it in a forked process. If the code succeeds it will be executed in the parent process. You can test things like passing a function a null pointer and make sure it doesnt dereference it and crash.

  dies_ok({abort();}, "abort does close your program");
  dies_ok({int x = 0/0;}, "divide by zero crash");
  lives_ok({pow(3.0, 5.0);}, "nothing wrong with taking 3**5");
  

  On Windows, these macros are the equivalent of a skip.

• done_testing()

  Summarizes the tests that occurred and exits the main function. If there was no plan, it will print out the number of tests as.

  1..5
  

  It will also print a diagnostic message about how many failures there were.

  # Looks like you failed 2 tests of 3 run.
  

  If all planned tests were successful, it will return 0. If any test fails, it will return 1. If they all passed, but there were missing tests, it will return 2.

• diag(fmt, ...)

  print out a message to the tap output on stdout. Each line is preceeded by a "# " so that you know its a diagnostic message.

  diag("This is\na diag\nto describe\nsomething.");
  

  prints:

  # This is
  # a diag
  # to describe
  # something
  

  ok() and this function return an int so you can use it like:

  ok(0) || diag("doh!");
  

• skip(test, n)

• skip(test, n, fmt, ...)

• end_skip

  Skip a series of n tests if test is true. You may give a reason why you are skipping them or not. The (possibly) skipped tests must occur between the skip and end_skip macros.

  skip(TRUE, 2);
  ok(1);
  ok(0);
  end_skip;
  

  prints:

  ok 1 # skip
  ok 2 # skip
  

• todo()

• todo(fmt, ...)

• end_todo

  Specifies a series of tests that you expect to fail because they are not yet implemented.

  todo()
  ok(0);
  end_todo;
  

  prints:

  not ok 1 # TODO
  #   Failed (TODO) test at todo.c line 7
  

• BAIL_OUT()

• BAIL_OUT(fmt, ...)

  Immediately stops all testing.

  BAIL_OUT("Can't go no further");
  

  prints

  Bail out!  Can't go no further
  

  and exits with 255.