Test::CPAN::Meta::JSON::Version - Validate CPAN META data against the specification


  use Test::CPAN::Meta::JSON::Version;


This module was written to ensure that a META.json file, provided with a standard distribution uploaded to CPAN, meets the specifications that are slowly being introduced to module uploads, via the use of ExtUtils::MakeMaker, Module::Build and Module::Install.

This module is meant to be used together with Test::CPAN::Meta::JSON, however the code is self contained enough that you can access it directly.

See CPAN::Meta for further details of the CPAN Meta Specification.


Validation of META.json data against the CPAN Meta Specification.


  • new( data => $data [, spec => $version] )

    The constructor must be passed a valid data structure.

    Optionally you may also provide a specification version. This version is then use to ensure that the given data structure meets the respective specification definition. If no version is provided the module will attempt to deduce the appropriate specification version from the data structure itself.


Main Methods

  • parse()

    Using the given data structure provided with the constructor, attempts to parse and validate according to the appropriate specification definition.

    Returns 1 if any errors found, otherwise returns 0.

  • errors()

    Returns a list of the errors found during parsing.

Check Methods

  • check_map($spec,$data)

    Checks whether a map (or hash) part of the data structure conforms to the appropriate specification definition.

  • check_lazylist($spec,$data)

    If it's a string, make it into a list and check the list

  • check_list($spec,$data)

    Checks whether a list (or array) part of the data structure conforms to the appropriate specification definition.

Validator Methods

  • url($self,$key,$value)

    Validates that a given value is in an acceptable URL format

  • urlspec($self,$key,$value)

    Validates that the URL to a META.yml specification is a known one.

  • string_or_undef($self,$key,$value)

    Validates that the value is either a string or an undef value. Bit of a catchall function for parts of the data structure that are completely user defined.

  • string($self,$key,$value)

    Validates that a string exists for the given key.

  • file($self,$key,$value)

    Validate that a file is passed for the given key. This may be made more thorough in the future. For now it acts like \&string.

  • exversion($self,$key,$value)

    Validates a list of versions, e.g. '<= 5, >=2, ==3, !=4, >1, <6, 0'.

  • version($self,$key,$value)

    Validates a single version string. Versions of the type '5.8.8' and '0.00_00' are both valid. A leading 'v' like 'v1.2.3' is also valid.

  • boolean($self,$key,$value)

    Validates for a boolean value. Currently these values are '1', '0', 'true', 'false', however the latter 2 may be removed.

  • license($self,$key,$value)

    Validates that a value is given for the license. Returns 1 if an known license type, or 2 if a value is given but the license type is not a recommended one.

  • resource($self,$key,$value)

    Validates that the given key is in CamelCase, to indicate a user defined keyword.

  • keyword($self,$key,$value)

    Validates that key is in an acceptable format for the META.yml specification, i.e. any in the character class [-_a-z].

    For user defined keys, although not explicitly stated in the specifications (v1.0 - v1.4), the convention is to precede the key with a pattern matching qr{\Ax_}i. Following this any character from the character class [-_a-zA-Z] can be used. This clarification has been added to v2.0 of the specification.

  • identifier($self,$key,$value)

    Validates that key is in an acceptable format for the META.yml specification, for an identifier, i.e. any that matches the regular expression qr/[a-z][a-z_]/i.

  • module($self,$key,$value)

    Validates that a given key is in an acceptable module name format, e.g. 'Test::CPAN::Meta::JSON::Version'.

  • release_status($self,$key,$value)

    Validates that the value for 'release_status' is set appropriately for one of 'stable', 'testing' or 'unstable'.

  • custom_1($self,$key,$value)

    Validates custom keys based on camelcase only.

  • custom_2($self,$key,$value)

    Validates custom keys based on user defined (i.e. /^[xX]_/) only.

  • phase($self,$key,$value)

    Validates for a legal phase of a pre-requisite map.

  • relation($self,$key,$value)

    Validates for a legal relation, within a phase, of a pre-requisite map.

  • anything($self,$key,$value)

    Usually reserved for user defined structures, allowing them to be considered valid without a need for a specification definition for the structure.


There are no known bugs at the time of this release. However, if you spot a bug or are experiencing difficulties that are not explained within the POD documentation, please send an email to or submit a bug to the RT system ( However, it would help greatly if you are able to pinpoint problems or even supply a patch.

Fixes are dependent upon their severity and my availability. Should a fix not be forthcoming, please feel free to (politely) remind me.


Barbie, <> for Miss Barbell Productions,


  Copyright (C) 2009-2015 Barbie for Miss Barbell Productions

  This distribution is free software; you can redistribute it and/or
  modify it under the Artistic Licence v2.