Rapid

6.6easy start · #7 of 27
in Property-Based Testing Tools

Runs on self-hosted.

Rapid is ranked #7 of 27 in property-based testing tools on The Geeks Club. It runs on Self-hosted. There is a free plan.

Rapid plans and pricing

Rapid Free Open-source Go library · No dependencies outside the Go standard library github.com · 3 Oct 2026

Gopter 0 of 4 in the starter kit Lesson 16.9 QuickCheck 0 of 4 in the starter kit Lesson 26.9 fast-check 0 of 4 in the starter kit Lesson 36.8 Scala Hedgehog 0 of 4 in the starter kit Lesson 46.8 CsCheck 0 of 4 in the starter kit Lesson 56.6 Hypothesis 0 of 4 in the starter kit Lesson 66.6

What it does: Rapid is a Go library for property-based testing that checks user-defined properties against automatically generated test cases.
Automatic minimization: When a failure is found, Rapid automatically minimizes the failing test case before presenting it.
Data generation: Its type-safe generators use generics and bias data generation toward small values and edge cases.
Failure persistence: Rapid supports persisting minimized failing test cases and automatically rerunning them.
Dependencies: Rapid has no dependencies outside the Go standard library.
Fuzzing integration: The MakeFuzz function lets a Rapid test be used as a fuzz target for Go's standard fuzzer.
Usage: Rapid tests run with the standard go test command.
Configuration: Rapid's options can be set with flags prefixed -rapid. or corresponding RAPID_ environment variables.
Stability: The project says tests should continue to work across future releases with the same major version, subject to stated API-change exceptions.
License: Rapid is licensed under the Mozilla Public License Version 2.0.
Comparison limit: Compared with Go's testing.F.Fuzz, Rapid describes itself as better suited to structured data and state machine tests, while lacking coverage-guided feedback and mutations.
Price from: Free

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