如何在测试中简单地将信息发送到标准输出？

Question

It appears that simply putting a say , print , etc into a .t doesn't work. The output is hidden. So when using Test::More and Test::Tester how can I simply print something? I want this so I can play with some code while determining how to test it. note: it's ok if it's sent to stderr or only viewable using verbose. Also I dried using diag but that didn't appear to work just anywhere in the test.

Answer 1

If you run a test script directly, you will see the output of print -- tests are just Perl code. However, if you run your tests using a harness, what you see in the output will be determined by the harness, especially its verbosity level, and by whether you print to STDOUT or STDERR .

For another way to print messages within tests, see Diagnostics in the documentation for Test::More , notably:

diag(...);
note(...);

Experimenting with a script like this will quickly illustrate how things work:

# Example usages:
#     perl     some_test.t   # We see everything in output.
#     prove    some_test.t   # We see only diag() and STDERR.
#     prove -v some_test.t   # Everything again.

# In some_test.t
use strict;
use warnings;
use Test::More;

pass;

diag("diag()");
note("note()");
print        "STDOUT\n";
print STDERR "STDERR\n";

done_testing;