Provided by: libcarp-assert-more-perl_2.1.0-1_all 
NAME
Carp::Assert::More - Convenience assertions for common situations
VERSION
Version 2.1.0
SYNOPSIS
A set of convenience functions for common assertions.
use Carp::Assert::More;
my $obj = My::Object;
assert_isa( $obj, 'My::Object', 'Got back a correct object' );
DESCRIPTION
Carp::Assert::More is a convenient set of assertions to make the habit of writing
assertions even easier.
Everything in here is effectively syntactic sugar. There's no technical difference
between calling one of these functions:
assert_datetime( $foo );
assert_isa( $foo, 'DateTime' );
that are provided by Carp::Assert::More and calling these assertions from Carp::Assert
assert( defined $foo );
assert( ref($foo) eq 'DateTime' );
My intent here is to make common assertions easy so that we as programmers have no excuse
to not use them.
SIMPLE ASSERTIONS
assert_is( $string, $match [,$name] )
Asserts that $string matches $match.
assert_isnt( $string, $unmatch [,$name] )
Asserts that $string does NOT match $unmatch.
assert_like( $string, qr/regex/ [,$name] )
Asserts that $string matches qr/regex/.
The assertion fails either the string or the regex are undef.
assert_unlike( $string, qr/regex/ [,$name] )
Asserts that $string matches qr/regex/.
The assertion fails if the regex is undef.
assert_defined( $this [, $name] )
Asserts that $this is defined.
assert_undefined( $this [, $name] )
Asserts that $this is not defined.
assert_nonblank( $this [, $name] )
Asserts that $this is not a reference and is not an empty string.
NUMERIC ASSERTIONS
assert_numeric( $n [, $name] )
Asserts that $n looks like a number, according to "Scalar::Util::looks_like_number".
"undef" will always fail.
assert_integer( $this [, $name ] )
Asserts that $this is an integer, which may be zero or negative.
assert_integer( 0 ); # pass
assert_integer( 14 ); # pass
assert_integer( -14 ); # pass
assert_integer( '14.' ); # FAIL
assert_nonzero( $this [, $name ] )
Asserts that the numeric value of $this is defined and is not zero.
assert_nonzero( 0 ); # FAIL
assert_nonzero( -14 ); # pass
assert_nonzero( '14.' ); # pass
assert_positive( $this [, $name ] )
Asserts that $this is defined, numeric and greater than zero.
assert_positive( 0 ); # FAIL
assert_positive( -14 ); # FAIL
assert_positive( '14.' ); # pass
assert_nonnegative( $this [, $name ] )
Asserts that $this is defined, numeric and greater than or equal to zero.
assert_nonnegative( 0 ); # pass
assert_nonnegative( -14 ); # FAIL
assert_nonnegative( '14.' ); # pass
assert_nonnegative( 'dog' ); # pass
assert_negative( $this [, $name ] )
Asserts that the numeric value of $this is defined and less than zero.
assert_negative( 0 ); # FAIL
assert_negative( -14 ); # pass
assert_negative( '14.' ); # FAIL
assert_nonzero_integer( $this [, $name ] )
Asserts that the numeric value of $this is defined, an integer, and not zero.
assert_nonzero_integer( 0 ); # FAIL
assert_nonzero_integer( -14 ); # pass
assert_nonzero_integer( '14.' ); # FAIL
assert_positive_integer( $this [, $name ] )
Asserts that the numeric value of $this is defined, an integer and greater than zero.
assert_positive_integer( 0 ); # FAIL
assert_positive_integer( -14 ); # FAIL
assert_positive_integer( '14.' ); # FAIL
assert_positive_integer( '14' ); # pass
assert_nonnegative_integer( $this [, $name ] )
Asserts that the numeric value of $this is defined, an integer, and not less than zero.
assert_nonnegative_integer( 0 ); # pass
assert_nonnegative_integer( -14 ); # FAIL
assert_nonnegative_integer( '14.' ); # FAIL
assert_negative_integer( $this [, $name ] )
Asserts that the numeric value of $this is defined, an integer, and less than zero.
assert_negative_integer( 0 ); # FAIL
assert_negative_integer( -14 ); # pass
assert_negative_integer( '14.' ); # FAIL
REFERENCE ASSERTIONS
assert_isa( $this, $type [, $name ] )
Asserts that $this is an object of type $type.
assert_isa_in( $obj, \@types [, $description] )
Assert that the blessed $obj isa one of the types in "\@types".
assert_isa_in( $obj, [ 'My::Foo', 'My::Bar' ], 'Must pass either a Foo or Bar object' );
assert_empty( $this [, $name ] )
$this must be a ref to either a hash or an array. Asserts that that collection contains
no elements. Will assert (with its own message, not $name) unless given a hash or array
ref. It is OK if $this has been blessed into objecthood, but the semantics of checking
an object to see if it does not have keys (for a hashref) or returns 0 in scalar context
(for an array ref) may not be what you want.
assert_empty( 0 ); # FAIL
assert_empty( 'foo' ); # FAIL
assert_empty( undef ); # FAIL
assert_empty( {} ); # pass
assert_empty( [] ); # pass
assert_empty( {foo=>1} );# FAIL
assert_empty( [1,2,3] ); # FAIL
assert_nonempty( $this [, $name ] )
$this must be a ref to either a hash or an array. Asserts that that collection contains
at least 1 element. Will assert (with its own message, not $name) unless given a hash or
array ref. It is OK if $this has been blessed into objecthood, but the semantics of
checking an object to see if it has keys (for a hashref) or returns >0 in scalar context
(for an array ref) may not be what you want.
assert_nonempty( 0 ); # FAIL
assert_nonempty( 'foo' ); # FAIL
assert_nonempty( undef ); # FAIL
assert_nonempty( {} ); # FAIL
assert_nonempty( [] ); # FAIL
assert_nonempty( {foo=>1} );# pass
assert_nonempty( [1,2,3] ); # pass
assert_nonref( $this [, $name ] )
Asserts that $this is not undef and not a reference.
assert_hashref( $ref [,$name] )
Asserts that $ref is defined, and is a reference to a (possibly empty) hash.
NB: This method returns false for objects, even those whose underlying data is a hashref.
This is as it should be, under the assumptions that:
(a) you shouldn't rely on the underlying data structure of a particular class, and
(b) you should use "assert_isa" instead.
assert_hashref_nonempty( $ref [,$name] )
Asserts that $ref is defined and is a reference to a hash with at least one key/value
pair.
assert_arrayref( $ref [, $name] )
assert_listref( $ref [,$name] )
Asserts that $ref is defined, and is a reference to an array, which may or may not be
empty.
NB: The same caveat about objects whose underlying structure is a hash (see
"assert_hashref") applies here; this method returns false even for objects whose
underlying structure is an array.
"assert_listref" is an alias for "assert_arrayref" and may go away in the future. Use
"assert_arrayref" instead.
assert_arrayref_nonempty( $ref [, $name] )
Asserts that $ref is reference to an array that has at least one element in it.
assert_aoh( $ref [, $name ] )
Verifies that $array is an arrayref, and that every element is a hashref.
The array $array can be an empty arraref and the assertion will pass.
assert_coderef( $ref [,$name] )
Asserts that $ref is defined, and is a reference to a closure.
TYPE-SPECIFIC ASSERTIONS
assert_datetime( $date )
Asserts that $date is a DateTime object.
SET AND HASH MEMBERSHIP
assert_in( $string, \@inlist [,$name] );
Asserts that $string matches one of the elements of \@inlist. $string may be undef.
\@inlist must be an array reference of non-ref strings. If any element is a reference,
the assertion fails.
assert_exists( \%hash, $key [,$name] )
assert_exists( \%hash, \@keylist [,$name] )
Asserts that %hash is indeed a hash, and that $key exists in %hash, or that all of the
keys in @keylist exist in %hash.
assert_exists( \%custinfo, 'name', 'Customer has a name field' );
assert_exists( \%custinfo, [qw( name addr phone )],
'Customer has name, address and phone' );
assert_lacks( \%hash, $key [,$name] )
assert_lacks( \%hash, \@keylist [,$name] )
Asserts that %hash is indeed a hash, and that $key does NOT exist in %hash, or that none
of the keys in @keylist exist in %hash. The list @keylist cannot be empty.
assert_lacks( \%users, 'root', 'Root is not in the user table' );
assert_lacks( \%users, [qw( root admin nobody )], 'No bad usernames found' );
assert_all_keys_in( \%hash, \@names [, $name ] )
Asserts that each key in %hash is in the list of @names.
This is used to ensure that there are no extra keys in a given hash.
assert_all_keys_in( $obj, [qw( height width depth )], '$obj can only contain height, width and depth keys' );
You can pass an empty list of @names.
assert_keys_are( \%hash, \@keys [, $name ] )
Asserts that the keys for %hash are exactly @keys, no more and no less.
CONTEXT ASSERTIONS
assert_context_nonvoid( [$name] )
Verifies that the function currently being executed has not been called in void context.
This is to ensure the calling function is not ignoring the return value of the executing
function.
Given this function:
sub something {
...
assert_context_scalar();
return $important_value;
}
These calls to "something" will pass:
my $val = something();
my @things = something();
but this will fail:
something();
assert_context_scalar( [$name] )
Verifies that the function currently being executed has been called in scalar context.
This is to ensure the calling function is not ignoring the return value of the executing
function.
Given this function:
sub something {
...
assert_context_scalar();
return $important_value;
}
This call to "something" will pass:
my $val = something();
but these will fail:
something();
my @things = something();
UTILITY ASSERTIONS
assert_fail( [$name] )
Assertion that always fails. "assert_fail($msg)" is exactly the same as calling
"assert(0,$msg)", but it eliminates that case where you accidentally use "assert($msg)",
which of course never fires.
COPYRIGHT & LICENSE
Copyright 2005-2022 Andy Lester.
This program is free software; you can redistribute it and/or modify it under the terms of
the Artistic License version 2.0.
ACKNOWLEDGEMENTS
Thanks to Eric A. Zarko, Bob Diss, Pete Krawczyk, David Storrs, Dan Friedman, Allard
Hoeve, Thomas L. Shinnick, and Leland Johnson for code and fixes.