# Agentic Coding Standards

This repository follows strict agentic coding practices to ensure high-quality, maintainable C++ implementations.

## Zero Defects Policy

All code changes must maintain a **zero defects policy**:
- Every feature or bug fix must be validated by passing tests before merge
- Code reviews focus on correctness, clarity, and adherence to style guidelines
- No known issues or technical debt should be introduced
- When defects are discovered, they are fixed immediately before proceeding with new work

## Test-Driven Development (TDD)

We follow the **Red-Green-Refactor** cycle strictly. You must invoke `./run_tests.sh` in each phase:

1. **Red**: Write a failing test that describes the desired behavior
2. **Green**: Write the minimum code necessary to make the test pass
3. **Refactor**: Improve the code while keeping tests passing

All development must start with a test. The repository includes one intentional failing test as a starting point for TDD workflow.

## Test Execution

Run the test suite using:

```bash
./run_tests.sh
```

This script:
- Configures the CMake build
- Compiles the vending machine library and test executable
- Executes all Google Test cases
- Reports results with clear pass/fail status

The test suite must pass entirely before any code is merged.

## Code Quality Standards

### Testing Framework
- **Test Framework**: Google Test (gtest) + Google Mock (gmock)
- **Coverage**: All public API functions must have test coverage
- **Organization**: Tests are located in `test/vending_machine_test.cpp`

### Code Style
- **Language Standard**: C++23
- **Style Tool**: clang-format (configuration in `.clang-format`)
- **Enforcement**: All code must pass `clang-format` validation before commit

## Agent Responsibilities

When assisting with code changes, agents must:
1. Respect the zero defects policy — all code must be tested and passing
2. Follow the Red-Green-Refactor workflow — tests first, implementation second
3. Enforce style compliance using clang-format standards
4. Ensure all tests pass before considering work complete
5. Maintain clarity and maintainability in all refactoring activities

## Getting Started

1. Read the failing test in `test/vending_machine_test.cpp`
2. Implement the vending machine interface in `include/vending_machine.h` and `src/` files
3. Run `./run_tests.sh` frequently to verify progress
4. Refactor once tests pass to improve code quality
5. Repeat for each new requirement