Christmas is at risk! In their rush to meet tight deadlines, Santa’s elves accidentally introduced bugs into critical algorithms. If these issues aren’t discovered in time, Christmas could be delayed for everyone worldwide!

Your mission is to troubleshoot these black-box algorithms using the power of fast-check.

The clock is ticking. Santa just pinged you with your first challenge: he’s struggling to answer children in the proper and efficient order. Something seems to be going wrong—can you uncover the issue and save Christmas? 🎄🔧

The previous release introduced the unit concept to the string arbitraries, enhancing control over string generation. In version 3.23.0, we’ve extended this feature to even more arbitraries, broadening its applicability. This update also includes several performance optimizations to make your testing faster and more efficient.

Continue reading to explore the detailed updates it brings.

This release extends string capabilities to generate not only printable ASCII characters but also a wider range of values, finely definable by the user. It also includes several deprecations.

Continue reading to explore the detailed updates it brings.

This release introduces support for UUIDs version 6 to 15. It also extends uuid to allow specifying a single version or a set of versions.

Continue reading to explore the detailed updates it brings.

Faker is a well-known and powerful library for generating fake data. It provides a wide range of random but realistic-looking data generators. However, testing with purely random data can be risky, which is why property-based testing is valuable. While using fake but realistic data in tests can be beneficial, it is essential to integrate it properly. fast-check offers a robust solution for this integration.

This release introduces new arbitraries to enhance shrinking capabilities and deprecates the noShrink and noBias methods in favor of these new arbitraries.

Continue reading to explore the detailed updates it brings.

This release introduces new opt-in options for objects arbitraries such as anything, object, json and jsonValue. These options provide more elegant and shorter ways to produce objects with non-ASCII keys and values.

Continue reading to explore the detailed updates it brings.

This release introduces some new opt-in options on floating point number arbitraries such as float and double. They offer simpler ways to only produce non-integer numerical values.

Continue reading to explore the detailed updates it brings.

This release exposes additional details regarding the random generator passed to the property. It unlocks the ability to delegate random value generation in the workers in the context of @fast-check/worker.

Continue reading to explore the detailed updates it brings.

This release makes fc.pre safer in terms of typings. It leverages the "assertion function" capability offered by TypeScript. This version has also been focused on preparing the monorepo to move to ECMAScript modules to build itself and on making our documentation better.

Continue reading to explore the detailed updates it brings.