Unity Test Runner

Overview

This skill enables automated execution and analysis of Unity Test Framework tests directly from the command line. It handles the complete test workflow: detecting Unity Editor installations across platforms (Windows/macOS/Linux), configuring test parameters, executing tests in EditMode or PlayMode, parsing NUnit XML results, and generating detailed failure reports with actionable insights.

When to Use This Skill

Use this skill when:

• Executing Unity Test Framework tests from command line
• Running PlayMode or EditMode tests for game logic validation
• Analyzing test failures and generating failure reports
• Integrating Unity tests into CI/CD pipelines
• Debugging test failures with detailed stack traces and file locations
• Validating Unity project changes before commits

Example user requests:

• "Run all Unity tests in my project"
• "Execute PlayMode tests and show me the results"
• "Run tests in the Combat category"
• "Check if my Unity tests are passing"
• "Run EditMode tests only"

Workflow

Follow this workflow when the skill is invoked:

1. Detect Unity Editor Installation

Use the find-unity-editor.js script to automatically locate the Unity Editor:

node scripts/find-unity-editor.js --json

Script behavior:

• Scans platform-specific default installation paths
• Detects all installed Unity versions
• Returns the latest version by default
• Can target specific version with --version <version> flag

Output:

{
  "found": true,
  "editorPath": "C:\\Program Files\\Unity\\Hub\\Editor\\2021.3.15f1\\Editor\\Unity.exe",
  "version": "2021.3.15f1",
  "platform": "win32",
  "allVersions": ["2021.3.15f1", "2020.3.30f1"]
}

If multiple versions are found:

1. Present all available versions to the user
2. Ask user to confirm which version to use
3. Or use the latest version by default

If no Unity Editor is found:

• Report error with searched paths
• Ask user to provide Unity Editor path manually
• Store the path for future use

2. Verify Unity Project Path

Confirm the current directory contains a valid Unity project using cross-platform checks:

// Use Read tool to check for Unity project indicators
Read({ file_path: "ProjectSettings/ProjectVersion.txt" })

// Use Glob to verify Assets directory exists
Glob({ pattern: "Assets/*", path: "." })

Validation steps:

1. Verify Assets/ directory exists
2. Verify ProjectSettings/ProjectVersion.txt exists
3. Read ProjectVersion.txt to get Unity version
4. Warn if Editor version doesn't match project version

Example ProjectVersion.txt:

m_EditorVersion: 2021.3.15f1
m_EditorVersionWithRevision: 2021.3.15f1 (e8e88743f9e5)

3. Configure Test Settings

Determine test execution parameters. Use AskUserQuestion tool if parameters are not specified:

Required settings:

• Test Mode: EditMode, PlayMode, or Both
• Test Platform: EditMode tests use "EditMode", PlayMode can specify platform (e.g., "StandaloneWindows64", "Android", "iOS")

Optional settings:

• Test Categories: Semicolon-separated list (e.g., "Combat;AI;Physics")
• Test Filter: Regex pattern or semicolon-separated test names
• Results Output Path: Default to TestResults.xml in project root

Configuration example:

AskUserQuestion({
  questions: [{
    question: "Which test mode should be executed?",
    header: "Test Mode",
    multiSelect: false,
    options: [
      { label: "EditMode Only", description: "Fast unit tests without Play Mode" },
      { label: "PlayMode Only", description: "Full Unity engine tests" },
      { label: "Both Modes", description: "Run all tests (slower)" }
    ]
  }]
})

4. Execute Tests via Command Line

Build and execute the Unity command line test command:

Command structure:

<UnityEditorPath> -runTests -batchmode -projectPath <ProjectPath> \
  -testPlatform <EditMode|PlayMode> \
  -testResults <OutputPath> \
  [-testCategory <Categories>] \
  [-testFilter <Filter>] \
  -logFile -

Example commands:

EditMode tests:

"C:\Program Files\Unity\Hub\Editor\2021.3.15f1\Editor\Unity.exe" \
  -runTests -batchmode \
  -projectPath "D:\Projects\MyGame" \
  -testPlatform EditMode \
  -testResults "TestResults-EditMode.xml" \
  -logFile -

PlayMode tests with category filter:

"C:\Program Files\Unity\Hub\Editor\2021.3.15f1\Editor\Unity.exe" \
  -runTests -batchmode \
  -projectPath "D:\Projects\MyGame" \
  -testPlatform PlayMode \
  -testResults "TestResults-PlayMode.xml" \
  -testCategory "Combat;AI" \
  -logFile -

Execution notes:

• Use Bash tool with run_in_background: true for long-running tests
• Set timeout appropriately (default: 5-10 minutes, adjust based on test count)
• Monitor output for progress indicators
• Capture both stdout and stderr

Example execution:

Bash({
  command: `"${unityPath}" -runTests -batchmode -projectPath "${projectPath}" -testPlatform EditMode -testResults "TestResults.xml" -logFile -`,
  description: "Execute Unity EditMode tests",
  timeout: 300000, // 5 minutes
  run_in_background: true
})

5. Parse Test Results

After tests complete, parse the NUnit XML results using parse-test-results.js:

node scripts/parse-test-results.js TestResults.xml --json

Script output:

{
  "summary": {
    "total": 10,
    "passed": 7,
    "failed": 2,
    "skipped": 1,
    "duration": 12.345
  },
  "failures": [
    {
      "name": "TestPlayerTakeDamage",
      "fullName": "Tests.Combat.PlayerTests.TestPlayerTakeDamage",
      "message": "Expected: 90\n  But was: 100",
      "stackTrace": "at Tests.Combat.PlayerTests.TestPlayerTakeDamage () [0x00001] in Assets/Tests/Combat/PlayerTests.cs:42",
      "file": "Assets/Tests/Combat/PlayerTests.cs",
      "line": 42
    }
  ],
  "allTests": [...]
}

Result analysis:

1. Extract test summary statistics
2. Identify all failed tests
3. Extract file paths and line numbers from stack traces
4. Categorize failures by type (assertion, exception, timeout)

6. Analyze Test Failures

For each failed test, analyze the failure using references/test-patterns.json:

Analysis steps:

1. Load test patterns database:

Read({ file_path: "references/test-patterns.json" })

2. Match failure message against patterns:

   • Assertion failures: Expected: <X> But was: <Y>
   • Null reference failures: Expected: not null But was: <null>
   • Timeout failures: TimeoutException|Test exceeded time limit
   • Threading errors: Can't be called from.*main thread
   • Object lifetime issues: has been destroyed|MissingReferenceException

3. Determine failure category:

   • ValueMismatch: Incorrect assertion value
   • NullValue: Unexpected null reference
   • Performance: Timeout or slow execution
   • TestSetup: Setup/TearDown failure
   • ObjectLifetime: Destroyed object access
   • Threading: Wrong thread execution

4. Generate fix suggestions:

   • Load common solutions from test-patterns.json
   • Match solutions to failure pattern
   • Provide concrete code examples

Example failure analysis:

**Test**: Tests.Combat.PlayerTests.TestPlayerTakeDamage
**Location**: Assets/Tests/Combat/PlayerTests.cs:42
**Result**: FAILED

**Failure Message**:
Expected: 90
  But was: 100

**Analysis**:
- Category: ValueMismatch (Assertion Failure)
- Pattern: Expected/actual value mismatch
- Root Cause: Player health not decreasing after TakeDamage() call

**Possible Causes**:
1. TakeDamage() method not implemented correctly
2. Player health not initialized properly
3. Damage value passed incorrectly

**Suggested Solutions**:
1. Verify TakeDamage() implementation:
   ```csharp
   public void TakeDamage(int damage) {
       health -= damage; // Ensure this line exists
   }

2. Check test setup:

   [SetUp]
   public void SetUp() {
       player = new Player();
       player.Health = 100; // Ensure proper initialization
   }
   

3. Verify test assertion:

   player.TakeDamage(10);
   Assert.AreEqual(90, player.Health); // Expected: 90
   

### 7. Generate Test Report

Create a comprehensive test report for the user:

**Report structure:**

```markdown
# Unity Test Results

## Summary
- **Total Tests**: 10
- **✓ Passed**: 7 (70%)
- **✗ Failed**: 2 (20%)
- **⊘ Skipped**: 1 (10%)
- **Duration**: 12.35s

## Test Breakdown
- **EditMode Tests**: 5 passed, 1 failed
- **PlayMode Tests**: 2 passed, 1 failed

## Failed Tests

### 1. Tests.Combat.PlayerTests.TestPlayerTakeDamage
**Location**: Assets/Tests/Combat/PlayerTests.cs:42

**Failure**: Expected: 90, But was: 100

**Analysis**: Player health not decreasing after TakeDamage() call.

**Suggested Fix**: Verify TakeDamage() implementation decreases health correctly.

---

### 2. Tests.AI.EnemyTests.TestEnemyChasePlayer
**Location**: Assets/Tests/AI/EnemyTests.cs:67

**Failure**: TimeoutException - Test exceeded time limit (5s)

**Analysis**: Infinite loop or missing yield in coroutine test.

**Suggested Fix**: Add `[UnityTest]` attribute and use `yield return null` in test loop.

---

## Next Steps
1. Review failed test locations and fix implementation
2. Re-run tests after fixes by re-invoking the skill
3. Consider adding more assertions for edge cases

Report delivery:

• Present report in formatted Markdown
• Highlight critical failures
• Provide file:line references for quick navigation
• Offer to help fix specific failures if user requests

Best Practices

When using this skill:

1. Run EditMode tests first - They're faster and catch basic logic errors

   • Reserve PlayMode tests for Unity-specific features
   • Use EditMode for pure C# logic and data structures

2. Use test categories - Filter tests for faster iteration

   • -testCategory "Combat" runs only Combat tests
   • Helpful during active development of specific features

3. Monitor test duration - Set appropriate timeouts

   • EditMode: 1-3 minutes typical
   • PlayMode: 5-15 minutes typical
   • Adjust timeout based on test count

4. Check Unity version compatibility - Ensure Editor matches project version

   • Mismatched versions may cause test failures
   • Test results may be inconsistent across versions

5. Parse results immediately - Don't wait for manual review

   • Automated parsing catches issues faster
   • Provides actionable file:line information

6. Analyze failure patterns - Look for common causes

   • Similar failures often indicate systemic issues
   • Fix root cause instead of individual symptoms

7. Preserve test results - Keep XML files for debugging

   • Results contain full stack traces
   • Useful for comparing test runs

8. Handle long-running tests - Use background execution

   • Monitor progress with BashOutput tool
   • Provide status updates to user

Resources

scripts/find-unity-editor.js

Cross-platform Unity Editor path detection script. Automatically scans default installation directories for Windows, macOS, and Linux, detects all installed Unity versions, and returns the latest version or a specific requested version.

Usage:

# Find latest Unity version
node scripts/find-unity-editor.js --json

# Find specific version
node scripts/find-unity-editor.js --version 2021.3.15f1 --json

Output: JSON with Unity Editor path, version, platform, and all available versions.

scripts/parse-test-results.js

NUnit XML results parser for Unity Test Framework output. Extracts test statistics, failure details, stack traces, and file locations from XML results.

Usage:

# Parse test results with JSON output
node scripts/parse-test-results.js TestResults.xml --json

# Parse with formatted console output
node scripts/parse-test-results.js TestResults.xml

Output: JSON with test summary, failure details including file paths and line numbers, and full test list.

references/test-patterns.json

Comprehensive database of Unity testing patterns, NUnit assertions, common failure patterns, and best practices. Includes:

• NUnit assertion reference (equality, collections, exceptions, Unity-specific)
• Common failure patterns with regex matching
• Failure categories and root cause analysis
• Solution templates with code examples
• EditMode vs PlayMode guidance
• Unity-specific testing patterns (coroutines, scenes, prefabs, physics)
• Testing best practices

Usage: Load this file when analyzing test failures to match failure messages against patterns and generate fix suggestions.