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Tools to generate test data from JSON schemata with Hypothesis
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.flake8 Overhaul build step Feb 14, 2019
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corpus-schemastore-catalog.json Tweak corpus and avoid collision Mar 24, 2019
corpus-suite-schemas.json Tweak corpus and avoid collision Mar 24, 2019
mypy.ini Allow dynamic typing for tests Nov 21, 2018
pytest.ini Drop pytest-mypy, just use mypy Mar 24, 2019
requirements.txt Drop pytest-mypy, just use mypy Mar 24, 2019 Officially go to Beta Mar 22, 2019 Tidy up corpus tests, marker application Mar 24, 2019


A Hypothesis strategy for generating data that matches some JSON schema.

Here's the PyPI page.


The public API consists of just one function: hypothesis_jsonschema.from_schema, which takes a JSON schema and returns a strategy for allowed JSON objects.

Schema reuse with "definitions" and "$ref" is not yet supported, but everything else in drafts 04, 05, and 07 is fully tested and working.

For details on how to use this strategy in your tests, see the Hypothesis docs.

Supported versions

hypothesis-jsonschema does not support Python 2, because it's close to end of life and Python 3.6+ is a much nicer language. Contact me if you would like this changed and are willing to either pay for or do the work to support Python 2.

In general, 0.x versions will require very recent versions of all dependencies because I don't want to deal with compatibility workarounds.

hypothesis-jsonschema may make backwards-incompatible changes at any time before version 1.x - that's what semver means! - but I've kept the API surface small enough that this should be avoidable. The main source of breaks will be if or when schema that never really worked turn into explicit errors instead of generating values that don't quite match.


0.8.1 - 2019-03-24

  • Supports draft-04 schemata with the latest version of jsonschema

0.8.0 - 2019-03-23

  • Further improved support for allOf, oneOf, and anyOf with base schemata
  • Added support for dependencies
  • Handles overlapping patternProperties

0.7.0 - 2019-03-21

  • Now requires jsonschema >= 3.0
  • Improved support for allOf, oneOf, and propertyNames
  • Supports schemata with "type": [an array of types]
  • Warning-free on Hypothesis 4.11

0.6.1 - 2019-02-23

  • Fix continuous delivery configuration (before the latent bug manifested)

0.6.0 - 2019-02-23

  • Support for conditional subschemata, i.e. the if, then, else keywords, and the anyOf, allOf, oneOf, and not keywords.

0.5.0 - 2019-02-22

  • Works with jsonschema 3.0 pre-release
  • Initial support for draft06 and draft07

0.4.2 - 2019-02-14

  • Dropped dependency on canonicaljson
  • Less warnings on Python 3.7

0.4.1 - 2019-02-06

  • Relicensed under the more permissive Mozilla Public License, like Hypothesis
  • Requires Hypothesis version 4.0 or later
  • Fixed an array bounds bug with maxItems and contains keywords

0.4.0 - 2018-11-25

Supports string formats (email, datetime, etc) and simple use of the "contains" keyword for arrays.

0.3.0 - 2018-11-25

Good support for all basic types. MVP.

0.2.0 - 2018-11-24

Inference for null, boolean, string, and numeric types.

0.1.0 - 2018-11-21

Stake in the ground (generate arbitrary JSON and filter it!)

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