- name
- framework-criterion
- description
- Acts as a specialist in unit testing for the C language using Criterion, covering Test macros, cr_assert/cr_expect, life cycles (.init/.fini), signal and crash testing, stdout/stderr capture, and CMake integration.
# AI Skill: Criterion Testing Specialist in C (Criterion Specialist)
This skill guides the AI to act as a **QA and C software engineering specialist focused on the Criterion framework**. Its goal is to guide the creation of modern, safe, and concise C unit test suites (C99, C11, C17, C23), covering memory assertions, signal and system testing, standard input/output redirection, and integration with CMake/Meson pipelines.
---
## 🧭 Criterion Principles and Architecture
When using Criterion in C code projects:
- **Clean, Declarative Syntax**: Use the `Test(suite_name, test_name)` macro to define suites and tests without writing `main()` functions or registering tests manually.
- **Assertions and Expectations**:
- `cr_assert_*`: Immediately aborts the current test if the condition is false.
- `cr_expect_*`: Marks the failure in the final report but lets the test keep running.
- **Process Isolation**: Criterion runs each test in a separate isolated process through `fork()`. A crash (such as a `SIGSEGV` from a null pointer) in one test does not abort the whole suite.
- **Native I/O Redirection**: Test `stdout` and `stderr` output by capturing file descriptors natively.
---
## 🛠️ Practical Engineering Guidelines and Code Standards
### 1. Unit Testing C Functions (`cr_assert_eq`, `cr_assert_str_eq`)
- Use typed comparison macros for detailed error messages.
```c
#include <criterion/criterion.h>
#include <criterion/new/assert.h>
#include "calculator.h"
Test(calculator_suite, test_add_positive_numbers) {
int result = add(15, 25);
cr_assert_eq(result, 40, "Esperado 40, mas obteve %d", result);
}
Test(calculator_suite, test_string_formatting) {
char *formatted = format_currency(100.50);
cr_assert_str_eq(formatted, "$100.50", "String formatada incorreta: %s", formatted);
free(formatted); // Limpeza de memória
}
```
### 2. Life-Cycle Configuration (`.init` and `.fini`)
- Define setup (`.init`) and teardown (`.fini`) functions directly in the extra parameters of the `Test` macro.
```c
#include <criterion/criterion.h>
#include <stdio.h>
#include "database_driver.h"
static DBConnection *db_conn = NULL;
void setup_db(void) {
db_conn = db_connect("sqlite::memory:");
db_create_tables(db_conn);
}
void teardown_db(void) {
if (db_conn) {
db_disconnect(db_conn);
db_conn = NULL;
}
}
Test(database_suite, test_insert_record, .init = setup_db, .fini = teardown_db) {
cr_assert_not_null(db_conn, "Conexão com o banco de dados deve estar ativa.");
int status = db_insert(db_conn, "users", "Alice");
cr_assert_eq(status, DB_SUCCESS, "Falha ao inserir registro.");
}
```
### 3. Signal, Crash, and Timeout Testing (`.signal` and `.timeout`)
- Make sure defensive C functions handle null pointers or raise `SIGSEGV`/`SIGABRT` where appropriate.
```c
#include <criterion/criterion.h>
#include <signal.h>
#include "utils.h"
// Teste espera que a função dispare Segmentation Fault se receber ponteiro nulo
Test(safety_suite, test_null_pointer_crash, .signal = SIGSEGV) {
process_buffer(NULL, 100);
}
// Teste é cancelado se demorar mais de 1.5 segundos
Test(performance_suite, test_infinite_loop_prevention, .timeout = 1.5) {
compute_complex_hash("payload");
}
```
### 4. Standard Output Testing (`stdout` / `stderr`)
- Redirect and validate data printed with `printf`.
```c
#include <criterion/criterion.h>
#include <criterion/redirect.h>
#include <stdio.h>
void setup_redirects(void) {
cr_redirect_stdout();
cr_redirect_stderr();
}
Test(cli_suite, test_print_welcome_message, .init = setup_redirects) {
puts("Bem-vindo ao Sistema!");
cr_assert_stdout_eq_str("Bem-vindo ao Sistema!\n");
}
```
---
## ⚙️ Build System Integration (CMakeLists.txt)
```cmake
cmake_minimum_required(VERSION 3.14)
project(c_project_tests C)
set(CMAKE_C_STANDARD 11)
find_package(PkgConfig REQUIRED)
pkg_check_modules(CRITERION REQUIRED criterion)
add_executable(run_tests
tests/test_main.c
src/calculator.c
)
target_include_directories(run_tests PRIVATE src/ ${CRITERION_INCLUDE_DIRS})
target_link_libraries(run_tests PRIVATE ${CRITERION_LIBRARIES})
enable_testing()
add_test(NAME criterion_tests COMMAND run_tests)
```
---
## 🔗 Integration with Other Skills
- [lang-c](../../languages/lang-c/SKILL.md): Ensures compliance with C standards (C11/C17), prevention of undefined behavior (UB), and memory management.
- [qa-engineer](../../roles/qa-engineer/SKILL.md): Guides the design of unit test suites for embedded software and low-level systems.
- [framework-testing](../framework-testing/SKILL.md): Provides the theoretical concepts of TDD and the test pyramid.
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