Add Header test

src/HUDMergerTests/Extensions/KeyValuesExtensionsTests.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Linq;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using VDF.Models;
+
+namespace HUDMerger.Extensions.Tests;
+
+[TestClass()]
+public class KeyValuesExtensionsTests
+{
+	[TestMethod()]
+	public void HeaderTest()
+	{
+		// Header
+		Assert.AreEqual([], new KeyValues([new KeyValue { Key = "Resource/HudLayout.res", Value = new KeyValues(), Conditional = null }]).Header());
+
+		// Ignore conditional
+		Assert.AreEqual([], new KeyValues([new KeyValue { Key = "Resource/HudLayout.res", Value = new KeyValues(), Conditional = "[$WIN32]" }]).Header());
+
+		// Replace string
+		Assert.AreEqual([], new KeyValues([new KeyValue { Key = "Resource/HudLayout.res", Value = "", Conditional = null }]).Header());
+
+		// Return KeyValues
+		Assert.AreEqual([], new KeyValues().Header());
+
+		// Append Header
+		KeyValues keyValues = [];
+		Assert.AreEqual([], keyValues.Header("Resource/HudLayout.res"));
+		Assert.IsTrue(keyValues.Any((kv) => kv.Key == "Resource/HudLayout.res" && kv.Value is KeyValues));
+
+		// hudanimations_manifest (https://github.com/cooolbros/hud-merger/issues/3)
+		Assert.AreEqual([], new KeyValues().Header("hudanimations_manifest"));
+	}
+}