Unity Testing

Unity Testing

Expert knowledge of Unity testing patterns, EditMode/PlayMode tests, and test-driven development for the Zero-Day Attack project.

Test Types

EditMode Tests

Run without entering Play mode - fast iteration:

PlayMode Tests

Run in simulated Play mode - test runtime behavior:

Project Test Structure

Assets/Tests/
├── Editor/
│   ├── BoardLayoutConfigTests.cs    # LayoutConfig validation
│   └── TileDatabaseTests.cs         # Database integrity
└── Runtime/
    ├── CoordinateConversionTests.cs # Grid-to-world conversion
    └── GameInitializationTests.cs   # Startup and state

Writing EditMode Tests

EditMode Test Basic Structure

using NUnit.Framework;
using ZeroDayAttack.Config;

namespace ZeroDayAttack.Tests.Editor
{
    [TestFixture]
    public class LayoutConfigTests
    {
        [Test]
        public void GridSize_ShouldBeFive()
        {
            Assert.AreEqual(5, LayoutConfig.GridSize);
        }

        [Test]
        public void ScreenDimensions_ShouldMatch1920x1080()
        {
            // At 100 PPU: 1920/100 = 19.2, 1080/100 = 10.8
            Assert.AreEqual(19.2f, LayoutConfig.ScreenWidth, 0.001f);
            Assert.AreEqual(10.8f, LayoutConfig.ScreenHeight, 0.001f);
        }

        [Test]
        public void CameraOrthoSize_ShouldBeHalfHeight()
        {
            float expectedOrtho = LayoutConfig.ScreenHeight / 2f;
            Assert.AreEqual(expectedOrtho, LayoutConfig.CameraOrthoSize, 0.001f);
        }
    }
}

Testing ScriptableObjects

using NUnit.Framework;
using UnityEngine;
using ZeroDayAttack.Core.Data;

namespace ZeroDayAttack.Tests.Editor
{
    [TestFixture]
    public class TileDatabaseTests
    {
        private TileDatabase database;

        [OneTimeSetUp]
        public void LoadDatabase()
        {
            database = Resources.Load<TileDatabase>("TileDatabase");
        }

        [Test]
        public void Database_ShouldLoad()
        {
            Assert.IsNotNull(database, "TileDatabase not found in Resources");
        }

        [Test]
        public void Database_ShouldHave25Tiles()
        {
            Assert.AreEqual(25, database.Tiles.Count);
        }

        [Test]
        public void AllTiles_ShouldHaveSprites()
        {
            foreach (var tile in database.Tiles)
            {
                Assert.IsNotNull(tile.TileSprite,
                    $"Tile {tile.TileId} missing sprite");
            }
        }
    }
}

Writing PlayMode Tests

PlayMode Test Basic Structure

using System.Collections;
using NUnit.Framework;
using UnityEngine;
using UnityEngine.TestTools;
using ZeroDayAttack.View;

namespace ZeroDayAttack.Tests.Runtime
{
    [TestFixture]
    public class TileManagerTests
    {
        private TileManager tileManager;

        [UnitySetUp]
        public IEnumerator SetUp()
        {
            // Create test object
            var go = new GameObject("TileManager");
            tileManager = go.AddComponent<TileManager>();
            yield return null;  // Wait one frame
        }

        [UnityTearDown]
        public IEnumerator TearDown()
        {
            if (tileManager != null)
            {
                Object.Destroy(tileManager.gameObject);
            }
            yield return null;
        }

        [UnityTest]
        public IEnumerator Instance_ShouldBeSet()
        {
            yield return null;
            Assert.IsNotNull(TileManager.Instance);
        }

        [UnityTest]
        public IEnumerator GridToWorld_CenterTile_ShouldBeAtOrigin()
        {
            yield return null;
            var worldPos = tileManager.GetWorldPosition(2, 2);
            Assert.AreEqual(0f, worldPos.x, 0.001f);
            Assert.AreEqual(0f, worldPos.y, 0.001f);
        }
    }
}

Testing with Scenes

using UnityEngine.SceneManagement;

[UnityTest]
public IEnumerator GameplayScene_ShouldLoad()
{
    SceneManager.LoadScene("GameplayScene");
    yield return null;  // Wait for load

    var gameManager = GameObject.FindObjectOfType<GameManager>();
    Assert.IsNotNull(gameManager);
}

Common Assertions

Value Assertions

Assert.AreEqual(expected, actual);
Assert.AreEqual(expected, actual, delta);  // For floats
Assert.AreNotEqual(notExpected, actual);
Assert.IsTrue(condition);
Assert.IsFalse(condition);

Null Assertions

Assert.IsNull(obj);
Assert.IsNotNull(obj);

Collection Assertions

Assert.Contains(item, collection);
Assert.IsEmpty(collection);
Assert.IsNotEmpty(collection);
CollectionAssert.AreEqual(expected, actual);
CollectionAssert.AreEquivalent(expected, actual);  // Order-independent

Exception Assertions

Assert.Throws<ArgumentException>(() => {
    SomeMethod(invalidArg);
});

Assert.DoesNotThrow(() => {
    SomeMethod(validArg);
});

Running Tests via MCP

Run All EditMode Tests

{
  "testMode": "EditMode"
}

Run Specific Test Class

{
  "testMode": "EditMode",
  "testClass": "LayoutConfigTests"
}

Run Specific Test Method

{
  "testMode": "EditMode",
  "testMethod": "ZeroDayAttack.Tests.Editor.LayoutConfigTests.GridSize_ShouldBeFive"
}

Useful Options

{
  "testMode": "EditMode",
  "includePassingTests": false, // Only show failures
  "includeMessages": true, // Include assertion messages
  "includeStacktrace": true, // Include stack traces
  "includeLogs": true // Include console logs
}

Test Naming Conventions

Pattern: Method_Scenario_ExpectedResult

[Test] public void GridToWorld_CenterTile_ReturnsOrigin() { }
[Test] public void PlaceTile_InvalidPosition_ThrowsException() { }
[Test] public void MoveToken_ValidPath_UpdatesPosition() { }

Test Class Naming

public class GameManagerTests { }      // Tests for GameManager
public class TileValidationTests { }   // Tests for tile validation logic
public class PathFindingTests { }      // Tests for path algorithms

Test Categories

Organize tests with categories:

[Test]
[Category("FastTests")]
public void QuickCalculation_Test() { }

[Test]
[Category("Integration")]
public void SceneSetup_Test() { }

Run by category:

{
  "testMode": "EditMode",
  "testCategory": "FastTests"
}

Testing Best Practices

Arrange-Act-Assert Pattern

[Test]
public void PathSegment_RotateBy90_UpdatesNodes()
{
    // Arrange
    var segment = new PathSegment(EdgeNode.Left, EdgeNode.Top, PathColor.Blue);

    // Act
    var rotated = segment.Rotate(90);

    // Assert
    Assert.AreEqual(EdgeNode.Top, rotated.From);
    Assert.AreEqual(EdgeNode.Right, rotated.To);
}

One Assertion Per Test (When Practical)

// Good: Focused tests
[Test] public void Tile_HasCorrectWidth() { }
[Test] public void Tile_HasCorrectHeight() { }

// OK for related properties
[Test]
public void Tile_HasCorrectDimensions()
{
    Assert.AreEqual(2.0f, tile.Width);
    Assert.AreEqual(2.0f, tile.Height);
}

Test Independence

Each test should be independent:

• Use [SetUp] for common initialization
• Use [TearDown] for cleanup
• Don't rely on test execution order

Fast Tests

Prefer EditMode tests when possible:

• No scene loading overhead
• Pure logic tests run instantly
• Use PlayMode only when necessary

Existing Tests

BoardLayoutConfigTests

Tests LayoutConfig constants:

• Grid dimensions
• Screen dimensions
• Camera settings
• Zone coordinates

TileDatabaseTests

Tests TileDatabase integrity:

• Database loads from Resources
• Correct tile count (25)
• All tiles have sprites
• All tiles have valid path data

CoordinateConversionTests

Tests TileManager coordinate conversion:

• Grid-to-world mapping
• Center tile at origin
• Corner positions correct

GameInitializationTests

Tests game startup:

• Managers initialize correctly
• Scene hierarchy valid
• Initial state correct

Mocking & Isolation

For Unity testing without external dependencies:

Common Mistakes

When to Use EditMode vs PlayMode

Reference Files

This skill's references/ folder contains:

Running Tests

In Unity Editor

Window > General > Test Runner

• EditMode tab for editor tests
• PlayMode tab for runtime tests

Via MCP

Enable testing group: /unity-mcp-enable testing

Then use tests-run tool with filter options.