Test::JSON::Schema::Acceptance - Acceptance testing for JSON-Schema based validators


version 1.018


This module allows the JSON Schema Test Suite tests to be used in perl to test a module that implements the JSON Schema specification ("json-schema"). These are the same tests that many modules (libraries, plugins, packages, etc.) use to confirm support of json-schema. Using this module to confirm support gives assurance of interoperability with other modules that run the same tests in different languages.

In the JSON::Schema::Modern module, a test could look like the following:

  use Test::More;
  use JSON::Schema::Modern;
  use Test::JSON::Schema::Acceptance;

  my $accepter = Test::JSON::Schema::Acceptance->new(specification => 'draft7');

    validate_data => sub ($schema, $input_data) {
      return JSON::Schema::Modern->new($schema)->validate($input_data);
    todo_tests => [ { file => 'dependencies.json' } ],


This would determine if JSON::Schema::Modern's validate method returns the right result for all of the cases in the JSON Schema Test Suite, except for those listed in $skip_tests.


JSON Schema is an IETF draft (at time of writing) which allows you to define the structure of JSON.

From the overview of the draft 2020-12 version of the specification:

    This document proposes a new media type "application/schema+json" to identify a JSON Schema for describing JSON data. It also proposes a further optional media type, "application/schema-instance+json", to provide additional integration features. JSON Schemas are themselves JSON documents. This, and related specifications, define keywords allowing authors to describe JSON data in several ways.

    JSON Schema uses keywords to assert constraints on JSON instances or annotate those instances with additional information. Additional keywords are used to apply assertions and annotations to more complex JSON data structures, or based on some sort of condition.

This module allows other perl modules (for example JSON::Schema::Modern) to test that they are JSON Schema-compliant, by running the tests from the official test suite, without having to manually convert them to perl tests.

You are unlikely to want this module, unless you are attempting to write a module which implements JSON Schema the specification, and want to test your compliance.


  Test::JSON::Schema::Acceptance->new(specification => $specification_version)

Create a new instance of Test::JSON::Schema::Acceptance.

Available options (which are also available as accessor methods on the object) are:


This determines the draft version of the schema to confirm compliance to. Possible values are:

  • draft3

  • draft4

  • draft6

  • draft7

  • draft2019-09

  • draft2020-12

  • latest (alias for draft2020-12)

  • draft-next

The default is latest, but in the synopsis example, JSON::Schema::Modern is testing draft 7 compliance.

(For backwards compatibility, new can be called with a single numeric argument of 3 to 7, which maps to draft3 through draft7.)


Instead of specifying a draft specification to test against, which will select the most appropriate tests, you can pass in the name of a directory of tests to run directly. Files in this directory should be .json files following the format described in


A directory of additional resources which should be made available to the implementation under the base URI http://localhost:1234. This is automatically provided if you did not override /test_dir; otherwise, you need to supply it yourself, if any tests require it (for example by containing {"$ref": "http://localhost:1234/foo.json/#a/b/c"}). If you supply an "add_resource" value to "acceptance" (see below), this will be done for you.


Optional. When true, prints version information and the test result table such that it is visible during make test or prove.


Optional. When true, tests in subdirectories (most notably optional/ are also included.


Optional. Pass a string or arrayref consisting of relative path name(s) to indicate directories (within the test directory as specified above with specification or test_dir) which will be skipped. Note that this is only useful currently with include_optional = 1>, as otherwise all subdirectories would be skipped anyway.


After calling "acceptance", a list of test results are provided here. It is an arrayref of hashrefs with four keys:

  • file - the filename

  • pass - the number of pass results for that file

  • todo_fail - the number of fail results for that file that were marked TODO

  • fail - the number of fail results for that file (not including TODO tests)


After calling "acceptance", a text string tabulating the test results are provided here. This is the same table that is printed at the end of the test run.


Optional. A boolean that, when true, will test every schema against its specification metaschema. (When set, specification must also be set.)

This normally should not be set as the official test suite has already been sanity-tested, but you may want to set this in development environments if you are using your own test files.

Defaults to false.



Accepts a hash of options as its arguments.

(Backwards-compatibility mode: accepts a subroutine which is used as validate_json_string, and a hashref of arguments.)

Available options are:


A subroutine reference, which is passed two arguments: the JSON Schema, and the inflated data structure to be validated. This is the main entry point to your JSON Schema library being tested.

The subroutine should return truthy or falsey depending on if the schema was valid for the input or not.

Either validate_data or validate_json_string is required.


A subroutine reference, which is passed two arguments: the JSON Schema, and the JSON string containing the data to be validated. This is an alternative to "validate_data" above, if your library only accepts JSON strings.

The subroutine should return truthy or falsey depending on if the schema was valid for the input or not.

Exactly one of validate_data or validate_json_string is required.


Optional. A subroutine reference, which will be called at the start of "acceptance" multiple times, with two arguments: a URI (string), and a data structure containing schema data to be associated with that URI, for use in some tests that use additional resources (see above). If you do not provide this option, you will be responsible for ensuring that those additional resources are made available to your implementation for the successful execution of the tests that rely on them.

For more information, see <>.


Optional. Restricts tests to just those mentioned (the conditions are ANDed together, not ORed). The syntax can take one of many forms:

  # run tests in this file
  tests => { file => 'dependencies.json' }

  # run tests in these files
  tests => { file => [ 'dependencies.json', 'refRemote.json' ] }

  # run tests in this file with this group description
  tests => {
    file => 'refRemote.json',
    group_description => 'remote ref',

  # run tests in this file with these group descriptions
  tests => {
    file => 'const.json',
    group_description => [ 'const validation', 'const with object' ],

  # run tests in this file with this group description and test description
  tests => {
    file => 'const.json',
    group_description => 'const validation',
    test_description => 'another type is invalid',

  # run tests in this file with this group description and these test descriptions
  tests => {
    file => 'const.json',
    group_description => 'const validation',
    test_description => [ 'same value is valid', 'another type is invalid' ],


Optional. Mentioned tests will run as "TODO". Uses arrayrefs of the same hashref structure as "tests" above, which are ORed together.

  todo_tests => [
    # all tests in this file are TODO
    { file => 'dependencies.json' },
    # just some tests in this file are TODO
    { file => 'boolean_schema.json', test_description => 'array is invalid' },
    # .. etc


Daniel Perrett <> for the concept and help in design.

Ricardo Signes <> for direction to and creation of Test::Fatal.

Various others in #perl-help.


Bugs may be submitted through

You can also find me on the JSON Schema Slack server and OpenAPI Slack server, which are also great resources for finding help.


Ben Hutton (@relequestual) <>


  • Karen Etheridge <>

  • Daniel Perrett <>


This software is Copyright (c) 2015 by Ben Hutton.

This is free software, licensed under:

  The MIT (X11) License

This distribution includes data from the test suite, which carries its own licence (see share/LICENSE).