UT Skill - Professional Unit Test Workflow

A comprehensive unit test generation skill for iOS, Android, and C++ platforms.

Quick Start

Simply type one of these commands in the chat:

# Generate UT for all changed files (compared to develop branch)
ut_changed

# Generate UT for changed files compared to specific branch
ut_changed --base=main

# Generate UT for all files in a directory
ut_path --path=phone/ios/Phone/Service

# Generate UT for specific files
ut_files --files="PhoneService.swift,CallManager.swift"

Commands

ut_changed

Analyzes git changes and generates unit tests for modified files.

ut_changed [--base=<branch>] [--platform=<ios|android|cpp|all>]

| Parameter | Default | Description | |-----------|---------|-------------| | --base | origin/dev | Base branch for comparison (uses remote to avoid stale local) | | --platform | all | Filter by platform |

Examples:

ut_changed
ut_changed --base=origin/dev
ut_changed --base=origin/main --platform=ios

ut_path

Generates unit tests for all source files in a directory.

ut_path --path=<directory> [--platform=<ios|android|cpp|all>]

| Parameter | Required | Description | |-----------|----------|-------------| | --path | Yes | Directory path to scan | | --platform | No | Filter by platform |

Examples:

ut_path --path=phone/ios/Phone/Service
ut_path --path=video/android/module-video/src/main/java/com/glip/video
ut_path --path=phone/cpp/core-phone/src --platform=cpp

ut_files

Generates unit tests for specific files.

ut_files --files="<file1,file2,...>" [--platform=<ios|android|cpp|all>]

| Parameter | Required | Description | |-----------|----------|-------------| | --files | Yes | Comma-separated file list | | --platform | No | Filter by platform |

Examples:

ut_files --files="UserService.swift,AuthManager.swift"
ut_files --files="PhoneService.kt" --platform=android

Workflow

The skill executes the following workflow:

1. File Analysis

• Detects changed files (local + branch diff)
• Filters by platform
• Excludes test files and non-testable files

2. Path Mapping

• Maps source files to test file locations
• Checks if test file already exists

3. Pre-Implementation

• Reads source file for analysis
• Finds similar tests for reference
• Identifies existing test coverage

4. Test Generation

• Generates tests following platform rules
• Achieves 100% branch coverage
• Achieves 100% code coverage
• Updates existing tests (no duplicates)

5. Build (iOS only)

• Prompts user to choose:
  • make ios_install_with_source
  • make ios_install_with_binary_cache

6. Test Execution

• Runs generated tests
• Collects coverage data

7. Coverage Report

• Displays line coverage
• Displays branch coverage
• Identifies missing coverage

Coverage Requirements

All generated tests must achieve:

• ✅ 100% Line Coverage
• ✅ 100% Branch Coverage

Platform Rules

The skill follows platform-specific testing rules:

| Platform | Rule File | |----------|-----------| | iOS | .cursor/rules/unit-test/ios-unit-test.mdc | | Android | .cursor/rules/unit-test/android-unit-test.mdc | | C++ | .cursor/rules/unit-test/cpp-unit-test.mdc | | Common | .cursor/rules/unit-test/unit-testing-principles.mdc |

Test Path Conventions

iOS

Source: phone/ios/Phone/Service/PhoneService.swift
Test:   phone/ios/Phone/Tests/PhoneServiceTests.swift

Android

Source: phone/android/module-phone/src/main/java/.../PhoneService.kt
Test:   phone/android/module-phone/src/test/java/.../PhoneServiceTest.kt

C++

Source: phone/cpp/core-phone/src/cc_lt/live_transcript_service.cpp
Test:   phone/cpp/core-phone/tests/src/cc_lt/live_transcript_service_test.cpp

Base Test Classes

| Platform | Base Class | Location | |----------|------------|----------| | iOS | XCBaseTestCase | common/ios/Common/UnitTestCommon/ | | Android | BaseRobolectricTest | Module test directories | | C++ | InitGlipCoreTest | */tests/ut_base/ |

Templates

Reference templates are available in:

• templates/ios-test-template.swift
• templates/android-test-template.kt
• templates/cpp-test-template.cpp

File Structure

.cursor/skills/ut-skill/
├── README.md           # This file
├── skill.md            # Skill overview
├── workflow.md         # Detailed workflow steps
├── trigger.mdc         # Command trigger rule
├── prompts/
│   ├── ut_changed.md   # ut_changed command prompt
│   ├── ut_path.md      # ut_path command prompt
│   └── ut_files.md     # ut_files command prompt
└── templates/
    ├── ios-test-template.swift
    ├── android-test-template.kt
    └── cpp-test-template.cpp

Key Principles

1. No Duplicates: Never create duplicate test files or methods
2. Update Mode: Modify existing tests rather than recreating
3. Reference Patterns: Use similar tests in the module as reference
4. Follow Standards: Strictly follow platform testing guidelines
5. Complete Coverage: Test all branches and code paths