---
name: "Test::Unit::Assertion::Regexp"
section: "3pm"
platform: "linux"
package: "libtest-unit-perl"
version: "0.27-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Test::Unit::Assertion::Regexp"
---

# Test::Unit::Assertion::Regexp(3pm)

Assertion with regex matching

## NAME

Test::Unit::Assertion::Regexp - Assertion with regex matching

## SYNOPSIS

```
    require Test::Unit::Assertion::Regexp;
    my $assert_re =
      Test::Unit::Assertion::Regexp->new(qr/a_pattern/);
    $assert_re->do_assertion('a_string');
```

This is rather more detail than the average user will need. Test::Unit::Assertion::Regexp objects are generated automagically by Test::Unit::Assert::assert when it is passed a regular expression as its first parameter.

```
    sub test_foo {
      ...
      $self->assert(qr/some_pattern/, $result);
    }
```

If the assertion fails then the object throws an exception with details of the pattern and the string it failed to match against.

Note that if you need to do a 'string does *not* match this pattern' type of assertion then you can do:

```
   $self->assert(qr/(?!some_pattern)/, $some_string)
```

ie. Make use of the negative lookahead assertion.

## IMPLEMENTS

Test::Unit::Assertion::Regexp implements the Test::Unit::Assertion interface, which means it can be plugged into the Test::Unit::TestCase and friends' `"assert"` method with no ill effects.

## DESCRIPTION

The class is used by the framework to provide sensible 'automatic' reports when a match fails. The old:

```
    $self->assert(scalar($foo =~ /pattern/), "$foo didn't match /.../");
```

seems rather clumsy compared to this. If the regexp assertion fails, then the user is given a sensible error message, with the pattern and the string that failed to match it...

## AUTHOR

Copyright (c) 2001 Piers Cawley \<pdcawley@iterative-software.com\>.

All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

## SEE ALSO

- •

  Test::Unit::TestCase

- •

  Test::Unit::Assertion