Functions

test_out

test_err

Procedures for predeclaring the output that your test suite is expected to produce until "test_test" is called. These procedures automatically assume that each line terminates with "\n". So

   test_out("ok 1","ok 2");
    

is the same as

   test_out("ok 1\nok 2");
    

which is even the same as

   test_out("ok 1");
   test_out("ok 2");
    

Once "test_out" or "test_err" (or "test_fail" or "test_diag") have been called, all further output from Test::Builder will be captured by Test::Builder::Tester. This means that you will not be able perform further tests to the normal output in the normal way until you call "test_test" (well, unless you manually meddle with the output filehandles)

test_fail

Because the standard failure message that Test::Builder produces whenever a test fails will be a common occurrence in your test error output, and because it has changed between Test::Builder versions, rather than forcing you to call "test_err" with the string all the time like so

    test_err("# Failed test ($0 at line ".line_num(+1).")");
    

"test_fail" exists as a convenience function that can be called instead. It takes one argument, the offset from the current line that the line that causes the fail is on.

    test_fail(+1);
    

This means that the example in the synopsis could be rewritten more simply as:

   test_out("not ok 1 - foo");
   test_fail(+1);
   fail("foo");
   test_test("fail works");
    

test_diag

As most of the remaining expected output to the error stream will be created by Test::Builder's "diag" function, Test::Builder::Tester provides a convenience function "test_diag" that you can use instead of "test_err".

The "test_diag" function prepends comment hashes and spacing to the start and newlines to the end of the expected output passed to it and adds it to the list of expected error output. So, instead of writing

   test_err("# Couldn't open file");
    

you can write

   test_diag("Couldn't open file");
    

Remember that Test::Builder's diag function will not add newlines to the end of output and test_diag will. So to check

   Test::Builder->new->diag("foo\n","bar\n");
    

You would do

  test_diag("foo","bar")
    

without the newlines.

test_test

Actually performs the output check testing the tests, comparing the data (with "eq") that we have captured from Test::Builder against what was declared with "test_out" and "test_err".

This takes name/value pairs that effect how the test is run.

line_num

A utility function that returns the line number that the function was called on. You can pass it an offset which will be added to the result. This is very useful for working out the correct text of diagnostic functions that contain line numbers.

Essentially this is the same as the "__LINE__" macro, but the "line_num(+3)" idiom is arguably nicer.

In addition to the six exported functions there exists one function that can only be accessed with a fully qualified function call.

color

When "test_test" is called and the output that your tests generate does not match that which you declared, "test_test" will print out debug information showing the two conflicting versions. As this output itself is debug information it can be confusing which part of the output is from "test_test" and which was the original output from your original tests. Also, it may be hard to spot things like extraneous whitespace at the end of lines that may cause your test to fail even though the output looks similar.

To assist you "test_test" can colour the background of the debug information to disambiguate the different types of output. The debug output will have its background coloured green and red. The green part represents the text which is the same between the executed and actual output, the red shows which part differs.

The "color" function determines if colouring should occur or not. Passing it a true or false value will enable or disable colouring respectively, and the function called with no argument will return the current setting.

To enable colouring from the command line, you can use the Text::Builder::Tester::Color module like so:

   perl -Mlib=Text::Builder::Tester::Color test.t
    

Or by including the Test::Builder::Tester::Color module directly in the PERL5LIB.