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Software Open Access

Hypothesis: Property-Based Testing for Python

MacIver, David R.; Hatfield-Dodds, Zac; many other contributors

This patch fixes invalid annotations detected for the tests generated by Ghostwritter. It will now correctly generate "Optional" types with just one type argument and handle union expressions inside of type arguments correctly. Additionally, it now supports code with the "from future import annotations" marker for Python 3.10 and newer.

The canonical version of these notes (with links) is on readthedocs.

If you use Hypothesis as part of a published research project, please cite our paper in the Journal of Open Source Software: Text: MacIver et al., (2019). Hypothesis: A new approach to property-based testing. Journal of Open Source Software, 4(43), 1891, BibTeX: @article{MacIver2019Hypothesis, journal = {Journal of Open Source Software}, doi = {10.21105/joss.01891}, issn = {2475-9066}, number = {43}, publisher = {The Open Journal}, title = {Hypothesis: A new approach to property-based testing}, url = {}, volume = {4}, author = {MacIver, David and Hatfield-Dodds, Zac and Contributors, Many}, pages = {1891}, date = {2019-11-21}, year = {2019}, month = {11}, day = {21}, } To reference a particular version of Hypothesis as a software artifact, you can use the version-specific DOIs we create for each release under
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