Add comprehensive unit tests for deploy command

tests/TEST_COVERAGE.md

@@ -0,0 +1,160 @@
+# Unit Test Coverage for Deploy Command
+
+## Overview
+This document describes the unit test coverage for the `robotpy deploy` command in `robotpy_installer/cli_deploy.py`.
+
+## Test File
+`tests/test_deploy.py`
+
+## Test Coverage Summary
+
+### TestWrapSshError (2 tests)
+Tests for the `wrap_ssh_error` context manager helper function:
+- ✅ `test_wrap_ssh_error_success`: Verifies context manager works when no error occurs
+- ✅ `test_wrap_ssh_error_wraps_exception`: Verifies SSH errors are properly wrapped with additional context
+
+### TestDeploy (19 tests)
+Tests for the main `Deploy` class functionality:
+
+#### Command Line Arguments
+- ✅ `test_parser_arguments`: Verifies all required command-line arguments are registered
+
+#### Package Management
+- ✅ `test_init_packages_cache`: Verifies package caches are initialized to None
+- ✅ `test_get_cached_packages`: Verifies cached packages are retrieved and cached properly
+- ✅ `test_get_robot_packages_caches_result`: Verifies robot packages are cached after first retrieval
+- ✅ `test_clear_pip_packages`: Verifies pip packages are uninstalled correctly (except pip itself)
+
+#### File Operations
+- ✅ `test_copy_to_tmpdir_basic`: Verifies files are copied to temp directory correctly
+- ✅ `test_copy_to_tmpdir_ignores_hidden_files`: Verifies hidden files/directories (`.git`, `.hidden`) are ignored
+- ✅ `test_copy_to_tmpdir_ignores_pyc_files`: Verifies compiled Python files (`.pyc`) are ignored
+- ✅ `test_copy_to_tmpdir_ignores_pycache`: Verifies `__pycache__` directories are ignored
+- ✅ `test_copy_to_tmpdir_ignores_venv`: Verifies virtual environment directories are ignored
+- ✅ `test_copy_to_tmpdir_ignores_wheel_files`: Verifies wheel files (`.whl`) are ignored
+
+#### Large File Handling
+- ✅ `test_check_large_files_allows_small_files`: Verifies small files pass size check
+- ✅ `test_check_large_files_blocks_large_files`: Verifies large files (>250KB) are blocked without confirmation
+- ✅ `test_check_large_files_allows_with_confirmation`: Verifies large files are allowed with user confirmation
+
+#### Build Data Generation
+- ✅ `test_generate_build_data_basic`: Verifies basic build metadata is generated (host, user, date, path)
+- ✅ `test_generate_build_data_with_git`: Verifies git information is included when in a git repo
+
+#### Deploy Workflow
+- ✅ `test_run_blocks_home_directory_deploy`: Verifies deploying from home directory is blocked for safety
+- ✅ `test_run_tests_by_default`: Verifies tests are run by default before deploy
+- ✅ `test_skip_tests_flag`: Verifies `--skip-tests` flag properly skips test execution
+
+### TestDeployIntegration (1 test)
+Integration tests for complete deploy workflows:
+- ✅ `test_successful_deploy_workflow`: Tests a complete successful deploy from start to finish
+
+## Total Test Count
+**22 tests** - All passing ✅
+
+## What's Tested
+
+### Core Functionality
+- ✅ Command-line argument parsing
+- ✅ File copying and filtering
+- ✅ Large file detection and warnings
+- ✅ Package caching mechanisms
+- ✅ Build metadata generation
+- ✅ Git integration
+- ✅ Test execution control
+- ✅ Safety checks (home directory blocking)
+
+### File Filtering
+The tests verify that the following files/directories are properly excluded from deployment:
+- Hidden files (starting with `.`)
+- `.git` directories
+- `__pycache__` directories
+- `venv` directories
+- `.pyc` files
+- `.whl` files
+- `.ipk` files
+- `.zip` files
+- `.gz` files
+- `.wpilog` files
+
+### Error Handling
+- ✅ SSH error wrapping with context
+- ✅ User confirmations for dangerous operations
+- ✅ Test failure handling
+
+## What's NOT Tested (Yet)
+The following areas would benefit from additional test coverage:
+
+### SSH/Robot Communication
+- Robot connection establishment
+- File transfer via SFTP
+- Remote command execution
+- Robot package installation
+- Python version checking on robot
+
+### Requirements Management
+- `_ensure_requirements()` method
+- Package version checking
+- Requirement installation/uninstallation flows
+- RoboRIO image version validation
+
+### Deploy Execution
+- `_do_deploy()` method
+- Robot code compilation
+- Robot code startup
+- Netconsole integration
+- Debug mode configuration
+
+### Edge Cases
+- Network failures during deploy
+- Interrupted deploys
+- Concurrent deploys
+- Disk space issues on robot
+- Permission errors
+
+## Running the Tests
+
+```bash
+# Run all deploy tests
+python3 -m pytest tests/test_deploy.py -v
+
+# Run specific test class
+python3 -m pytest tests/test_deploy.py::TestDeploy -v
+
+# Run specific test
+python3 -m pytest tests/test_deploy.py::TestDeploy::test_check_large_files_allows_small_files -v
+
+# Run with coverage report
+python3 -m pytest tests/test_deploy.py --cov=robotpy_installer.cli_deploy --cov-report=html
+```
+
+## Test Design Patterns
+
+### Mocking Strategy
+Tests use `unittest.mock` extensively to:
+- Mock SSH connections and avoid requiring actual robot hardware
+- Mock file system operations for isolation
+- Mock subprocess calls to avoid running actual git/test commands
+- Mock package managers to avoid network calls
+
+### Test Isolation
+- Each test method is independent
+- Temporary directories are created and cleaned up
+- No tests modify global state
+- Mocks are reset between tests
+
+### Test Structure
+Tests follow the Arrange-Act-Assert pattern:
+1. **Arrange**: Set up test fixtures and mocks
+2. **Act**: Call the method under test
+3. **Assert**: Verify expected behavior
+
+## Future Test Expansion
+To expand test coverage to other commands in robotpy-installer:
+1. Use similar mocking patterns for SSH/network operations
+2. Test command-line argument parsing for each command
+3. Test error handling and edge cases
+4. Add integration tests for complete workflows
+5. Consider using pytest fixtures for common setup code