Add unit tests and code coverage (78.3% coverage achieved)

Co-authored-by: abeckDev <8720854+abeckDev@users.noreply.github.com>

Author: Copilot

.gitignore

@@ -55,6 +55,9 @@ Generated\ Files/
 [Bb]uild[Ll]og.*
 *.trx
 
+# Code Coverage Results
+TestResults/
+
 # NUnit
 *.VisualState.xml
 TestResult.xml

AbeckDev.DbTimetable.Mcp.Test/AbeckDev.DbTimetable.Mcp.Test.csproj

@@ -0,0 +1,34 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net9.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.4">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.0" />
+    <PackageReference Include="Moq" Version="4.20.72" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\AbeckDev.DbTimetable.Mcp\AbeckDev.DbTimetable.Mcp.csproj" />
+  </ItemGroup>
+
+</Project>

AbeckDev.DbTimetable.Mcp.Test/ConfigurationTests.cs

@@ -0,0 +1,45 @@
+using AbeckDev.DbTimetable.Mcp.Models;
+
+namespace AbeckDev.DbTimetable.Mcp.Test;
+
+public class ConfigurationTests
+{
+    [Fact]
+    public void Configuration_SectionName_HasCorrectValue()
+    {
+        // Arrange & Act & Assert
+        Assert.Equal("DeutscheBahnApi", Configuration.SectionName);
+    }
+
+    [Fact]
+    public void Configuration_DefaultValues_AreCorrect()
+    {
+        // Arrange & Act
+        var config = new Configuration();
+
+        // Assert
+        Assert.Equal("https://apis.deutschebahn.com/db-api-marketplace/apis/timetables/v1/", config.BaseUrl);
+        Assert.Equal(string.Empty, config.ClientId);
+        Assert.Equal(string.Empty, config.ApiKey);
+    }
+
+    [Fact]
+    public void Configuration_Properties_CanBeSet()
+    {
+        // Arrange
+        var config = new Configuration();
+        var expectedBaseUrl = "https://test.api.com/";
+        var expectedClientId = "test-client-id";
+        var expectedApiKey = "test-api-key";
+
+        // Act
+        config.BaseUrl = expectedBaseUrl;
+        config.ClientId = expectedClientId;
+        config.ApiKey = expectedApiKey;
+
+        // Assert
+        Assert.Equal(expectedBaseUrl, config.BaseUrl);
+        Assert.Equal(expectedClientId, config.ClientId);
+        Assert.Equal(expectedApiKey, config.ApiKey);
+    }
+}