property-testing-guide

Generate property-based tests for Rust codebases using proptest.

2|1|Updated Oct 31, 2025

Search Tags:#testing #Rust #invariants #proptest #generators #property-testing

Ready to run

npx skills add https://github.com/EmilLindfors/claude-marketplace --skill property-testing-guide

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: property-testing-guide
Source: https://github.com/EmilLindfors/claude-marketplace/tree/main/plugins/rust-testing/skills/property-testing-guide
Command: npx skills add https://github.com/EmilLindfors/claude-marketplace --skill property-testing-guide

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

Explains property-based testing and how to generate broad input spaces for invariants.

Core Features & Use Cases

Strategy design: custom generators for domain types
Roundtrip and invariants: property assertions

Quick Start

Write a property-based test using proptest and define a custom strategy for a domain type.

Frequently Asked Questions about property-testing-guide

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

When should I use property-based testing instead of example-based tests?▼

Property-based testing generates broad input spaces to expose edge cases and invariants that fixed examples miss. Use it for algorithm implementations, data structures, serialization/deserialization, and code with numerous edge cases where manual test cases may overlook failure modes.

How do I write a property test with proptest in Rust?▼

Define a custom strategy as a generator for your domain type, then write a property assertion that validates an invariant across all generated inputs. Proptest will automatically sample the input space and shrink failures to minimal reproducers.

What are roundtrip tests and how do proptest strategies support them?▼

Roundtrip tests verify that data can be encoded and decoded without loss—for example, serialize then deserialize and compare. Proptest strategies generate diverse input values to validate these invariants across the full input space, catching serialization bugs.

Can I create custom generators for my own domain types with proptest?▼

Yes. Proptest lets you design custom strategies tailored to your domain types, controlling how inputs are generated, constrained, and shrunk. This enables targeted invariant checking specific to your data structures and business logic.

What kinds of bugs does property-based testing catch that example-based tests don't?▼

Property-based testing exposes boundary conditions, off-by-one errors, type edge cases, and interaction bugs across combinatorial input spaces. It systematically explores invariants rather than relying on developer intuition about which examples to test.

Do I need to know Rust well to set up proptest?▼

Proptest targets Rust codebases and requires familiarity with Rust syntax and traits. The Skill guides you through practical patterns like strategy definition and invariant checks, making it accessible once you're comfortable with Rust fundamentals.