schemathesis 4.4.0

Release 4.4.0

on Python PyPI

🚀 Added

• Support for custom content types in multipart/form-data encoding via OpenAPI's encoding property. #697
• Option to make warnings cause test failures via fail-on in warnings configuration. #2956
• The generation.allow-extra-parameters config option to control whether Schemathesis generates unexpected query, header, or cookie parameters in negative testing (set to false to skip them entirely).
• Response deserializer hook for non-JSON schema conformance checks (schemathesis.deserializer). #2934
• Automatic dependency inference in Python stateful tests via schema.as_state_machine().
• schemathesis.serializer.alias() to reuse built-in serializers (YAML, JSON, XML) for custom media types without reimplementing them. #2952
• Warning when API responses have structured schemas but no registered deserializer, helping catch silently skipped validation.

🐛 Fixed

• Curl commands with non-printable characters now use shell-aware escaping and display warnings for unknown shells. #2159
• Internal error when the coverage phase generates data not serializable into media type registered via schemathesis.openapi.media_type.
• Internal error when negative testing encounters schemas with bundled references.
• Internal error when processing link definitions missing both operationRef and operationId.
• CLI now starts displaying the current operation as soon as execution begins, preventing the blank progress window most noticeable during the coverage phase.

🔧 Changed

• Custom media type strategies now support wildcard patterns (e.g., image/*) for all request body types, not just multipart encoding.
• Improved the missing-links error message to point directly to the stateful testing guide.
• Dependency inference now extracts fields from nested wrapper objects (result, data, response, payload).

📝 Documentation

• Expanded the stateful testing guide with detailed link examples, troubleshooting tips, and CLI behaviour notes.