c-testing

Generates CMocka or Unity unit and integration tests for C (C11/C17) code.

7|Updated Apr 7, 2026
One-click install
npx skills add https://github.com/chenziyang110/spec-kit-plus --skill c-testing-chenziyang110
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: c-testing
Source: https://github.com/chenziyang110/spec-kit-plus/tree/main/templates/passive-skills/c-testing
Command: npx skills add https://github.com/chenziyang110/spec-kit-plus --skill c-testing-chenziyang110

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

It helps you add dependable unit and integration tests for C (C11/C17) code by generating structured CMocka/Unity test scaffolding and guidance for diagnosing failures.

Core Features & Use Cases

  • Test coverage for C components: Create unit tests that validate happy paths, boundary conditions, and error handling.
  • Mocking and isolation: Use function-pointer dependency injection patterns and CMocka expect_* assertions to isolate I/O and external effects.
  • Run and debug confidently: Provide verification steps using ctest and support for memory-safety checks via ASan/Valgrind when needed.

Quick Start

Use the c-testing skill when you want tests for a C module that already has (or should have) a test framework configuration, and ask the agent: "Write CMocka unit tests for the functions in src/math_utils.c, including boundary and failure cases, and show how to run them with ctest."

Frequently Asked Questions about c-testing

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

FAQPage Schema
How do I write CMocka unit tests for existing C code?

Generate CMocka unit tests for existing C code by creating structured test scaffolding that validates happy paths, boundary conditions, and error handling while using function-pointer dependency injection and expect_* assertions to isolate external effects.

How do I run CMocka tests using ctest?

Run CMocka tests using ctest by following the generated verification steps that integrate with your CMake build system to compile test binaries and execute them while reporting failures.

Does this C unit testing approach work for embedded systems?

Yes, this C unit testing approach works for embedded systems by generating test scaffolding that respects lightweight embedded constraints, ensuring compatibility with resource-limited C11 and C17 environments.

What is the best way to isolate dependencies in C unit tests?

Isolate dependencies in C unit tests by applying function-pointer dependency injection patterns combined with CMocka mocks, which intercept I/O and external effects to test components independently.

Can I use Valgrind and ASan to debug C unit test failures?

Yes, you can use Valgrind and ASan to debug C unit test failures by applying the provided memory-safety check guidance alongside ctest execution to detect leaks and memory violations.

Why are my C unit tests failing with ambiguous function behavior?

C unit tests fail with ambiguous function behavior when code lacks clear stop-conditions or is untestable, requiring you to define explicit test boundaries and isolate dependencies to resolve the failures.