Unity TestRunner - Automated Testing for Unity

Overview

Unity Test Framework provides NUnit-based testing with CLI automation for batch execution, CI/CD pipelines, and TDD workflows.

Core Topics:

• CLI batchmode test execution (EditMode/PlayMode)
• NUnit assertions and test attributes
• Test assembly configuration (asmdef)
• Result parsing and reporting
• CI/CD pipeline integration

Foundation Required: csharp-plugin:csharp-code-style (naming conventions, code organization)

Optional Integrations:

• unity-vcontainer: DI-based test mocking
• unity-unitask: Async test patterns
• unity-async: Coroutine testing utilities

Learning Path: Test basics → CLI automation → Advanced patterns → CI/CD integration

Quick Start

Basic Test Structure

using NUnit.Framework;

[TestFixture]
public class PlayerServiceTests
{
    private PlayerService mPlayerService;

    [SetUp]
    public void SetUp()
    {
        mPlayerService = new PlayerService();
    }

    [Test]
    public void Initialize_WhenCalled_SetsHealthToMax()
    {
        // Arrange
        int expected = 100;

        // Act
        mPlayerService.Initialize();

        // Assert
        Assert.AreEqual(expected, mPlayerService.Health);
    }

    [TearDown]
    public void TearDown()
    {
        mPlayerService = null;
    }
}

CLI Execution (EditMode)

& "C:\Program Files\Unity\Hub\Editor\{VERSION}\Editor\Unity.exe" `
  -batchmode `
  -nographics `
  -projectPath "{PROJECT_PATH}" `
  -runTests `
  -testPlatform editmode `
  -testResults "{TEMP}\results.xml" `
  -logFile "{TEMP}\test.log" `
  -quit

CLI Execution (PlayMode)

& "C:\Program Files\Unity\Hub\Editor\{VERSION}\Editor\Unity.exe" `
  -batchmode `
  -projectPath "{PROJECT_PATH}" `
  -runTests `
  -testPlatform playmode `
  -testResults "{TEMP}\results.xml" `
  -logFile "{TEMP}\test.log" `
  -quit

Note: PlayMode cannot use -nographics (requires scene rendering)

When to Use

Trigger Conditions (Proactive)

• Test code (Tests path .cs files) created or modified
• TDD workflow in progress (test-first development)
• User explicitly requests "run tests", "execute tests"
• CI/CD pipeline configuration needed
• Test failure debugging required

Non-Trigger Conditions

• General .cs file modifications without test context
• Configuration or asset file changes only
• Build or deployment tasks without test requirements

Reference Documentation

CLI Automation

Complete CLI reference and automation:

• Full CLI option reference table
• Unity Hub path detection (Windows/macOS)
• ProjectVersion.txt parsing
• Environment variable configuration
• CI/CD pipeline templates (GitHub Actions)
• Timeout and log management

Test Patterns

NUnit patterns and best practices:

• NUnit attribute reference ([Test], [SetUp], [TestCase], etc.)
• EditMode test patterns (pure C#, ScriptableObject)
• PlayMode test patterns (MonoBehaviour, Scene loading)
• Async test patterns (UniTask, IEnumerator)
• Test fixture configuration (asmdef-based)
• Mocking strategies (interface-based)

Result Parsing

Test result processing:

• NUnit XML result format structure
• PowerShell XML parsing snippets
• Result summary extraction
• Failed test detail extraction
• CI/CD reporting integration

Key Principles

1. EditMode First: Use EditMode for pure logic tests (faster, no scene required)
2. PlayMode for Integration: Reserve PlayMode for MonoBehaviour and scene tests
3. Isolate Dependencies: Use interfaces for testable architecture
4. Fast Feedback Loop: Filter tests during development for quick iteration
5. Automate in CI/CD: Configure batchmode execution for continuous testing

Common Patterns

Test Filtering

# Filter by test name (semicolon-separated)
-testFilter "LoginTest;AuthTest"

# Filter by regex pattern
-testFilter ".*Service.*"

# Filter by category
-testCategory "Unit;Integration"

# Filter by assembly
-assemblyNames "Game.Domain.Tests;Game.Service.Tests"

Unity Version Detection

# Parse ProjectVersion.txt
$versionFile = Get-Content "{PROJECT_PATH}/ProjectSettings/ProjectVersion.txt"
$version = ($versionFile | Select-String "m_EditorVersion: (.+)").Matches.Groups[1].Value

# Construct Unity Editor path
$unityExe = "C:\Program Files\Unity\Hub\Editor\$version\Editor\Unity.exe"

Test Assembly Identification

Priority pattern for finding test assemblies:
1. {AssemblyName}.Tests.asmdef (same folder or Tests subfolder)
2. Tests/{AssemblyName}/*.asmdef
3. Assets/Tests/EditMode/*.asmdef (fallback)

Example:
  Changed: Assets/Scripts/Domain/LoginService.cs
    -> asmdef: Game.Domain.asmdef
    -> Tests: Game.Domain.Tests.asmdef
    -> Filter: -assemblyNames "Game.Domain.Tests"

Exit Codes

Exit Code	Meaning	Action
0	All tests passed	Display summary
2	Test failures	Display failed test details
1	Other errors	Check log file for details

Result Summary Format

Unity Test Results (EditMode)
-----------------------------------
Passed: 15
Failed: 2
Skipped: 1
Duration: 3.45s

Failed Tests:
  1. LoginServiceTests.LoginWithInvalidCredentials_ThrowsException
     -> Expected: ArgumentException
     -> Actual: No exception thrown

  2. AuthTests.TokenExpiry_ShouldInvalidateSession
     -> Assert.AreEqual failed
     -> Expected: False, Actual: True

Platform Considerations

Windows

$unityExe = "C:\Program Files\Unity\Hub\Editor\{VERSION}\Editor\Unity.exe"

macOS

unityExe="/Applications/Unity/Hub/Editor/{VERSION}/Unity.app/Contents/MacOS/Unity"

CI/CD Environment

# Use environment variable for flexibility
$unityExe = $env:UNITY_EDITOR_PATH
if (-not $unityExe) {
    # Fallback to Unity Hub path
}

Error Handling

Error	Resolution
Unity Editor path not found	Set UNITY_EDITOR_PATH environment variable
ProjectVersion.txt missing	Verify Unity project root location
Test timeout	Use -playerHeartbeatTimeout option (default: 600s)
License error	Verify Unity license activation

Integration with Other Skills

• unity-vcontainer: Configure DI mocks in test fixtures
• unity-unitask: Write async tests with UniTask assertions
• unity-async: Test coroutine-based logic
• unity-performance: Profile test execution performance