Merge pull request #38 from joadan/copilot/add-tests-for-singleton

Add tests for SingletonBuilder

Author: joadan

test/Linq2OData.Tests/SingletonBuilderTests.cs

@@ -0,0 +1,290 @@
+using Linq2OData.Core;
+using Linq2OData.Core.Builders;
+using System.Net;
+
+namespace Linq2OData.Tests;
+
+/// <summary>
+/// Tests for the SingletonBuilder class, which builds requests for OData singleton entities.
+/// </summary>
+public class SingletonBuilderTests
+{
+	[ODataEntitySet("Persons")]
+	public class TestPerson : IODataEntitySet
+	{
+		[ODataMember("ID")]
+		public int ID { get; set; }
+
+		[ODataMember("Name")]
+		public string? Name { get; set; }
+
+		[ODataMember("Email")]
+		public string? Email { get; set; }
+
+		[ODataMember("Address", isComplex: true)]
+		public TestAddress? Address { get; set; }
+
+		public string __Key => $"ID={ID}";
+	}
+
+	[ODataEntitySet("Addresses")]
+	public class TestAddress : IODataEntitySet
+	{
+		[ODataMember("City")]
+		public string? City { get; set; }
+
+		public string __Key => "";
+	}
+
+	private (SingletonBuilder<TestPerson> builder, MockHttpHandler handler) CreateBuilder(
+		ODataVersion version = ODataVersion.V4,
+		string responseBody = "{}",
+		HttpStatusCode statusCode = HttpStatusCode.OK)
+	{
+		var handler = new MockHttpHandler(responseBody, statusCode);
+		var httpClient = new HttpClient(handler) { BaseAddress = new Uri("https://example.com/odata/") };
+		var odataClient = new ODataClient(httpClient, version);
+		return (new SingletonBuilder<TestPerson>(odataClient, "Me"), handler);
+	}
+
+	#region Builder State Tests
+
+	[Fact]
+	public void SingletonBuilder_Select_SetsSelectField()
+	{
+		// Arrange
+		var (builder, _) = CreateBuilder();
+
+		// Act
+		var result = builder.Select("Name,Email");
+
+		// Assert
+		Assert.Equal("Name,Email", builder.select);
+		Assert.Same(builder, result);
+	}
+
+	[Fact]
+	public void SingletonBuilder_Expand_SetsExpandField()
+	{
+		// Arrange
+		var (builder, _) = CreateBuilder();
+
+		// Act
+		var result = builder.Expand("Address");
+
+		// Assert
+		Assert.Equal("Address", builder.expand);
+		Assert.Same(builder, result);
+	}
+
+	[Fact]
+	public void SingletonBuilder_SelectNull_SetsSelectFieldToNull()
+	{
+		// Arrange
+		var (builder, _) = CreateBuilder();
+		builder.Select("Name");
+
+		// Act
+		builder.Select(null);
+
+		// Assert
+		Assert.Null(builder.select);
+	}
+
+	[Fact]
+	public void SingletonBuilder_ExpandNull_SetsExpandFieldToNull()
+	{
+		// Arrange
+		var (builder, _) = CreateBuilder();
+		builder.Expand("Address");
+
+		// Act
+		builder.Expand(null);
+
+		// Assert
+		Assert.Null(builder.expand);
+	}
+
+	[Fact]
+	public void SingletonBuilder_ChainSelectAndExpand_SetsBothFields()
+	{
+		// Arrange
+		var (builder, _) = CreateBuilder();
+
+		// Act
+		builder.Select("Name").Expand("Address");
+
+		// Assert
+		Assert.Equal("Name", builder.select);
+		Assert.Equal("Address", builder.expand);
+	}
+
+	[Fact]
+	public void SingletonBuilder_DefaultState_HasNullSelectAndExpand()
+	{
+		// Arrange / Act
+		var (builder, _) = CreateBuilder();
+
+		// Assert
+		Assert.Null(builder.select);
+		Assert.Null(builder.expand);
+	}
+
+	#endregion
+
+	#region URL Generation Tests
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_NoSelectOrExpand_RequestsCorrectUrl()
+	{
+		// Arrange
+		var json = """{"@odata.context":"https://example.com/odata/$metadata#Me","ID":1,"Name":"John"}""";
+		var (builder, handler) = CreateBuilder(ODataVersion.V4, json);
+
+		// Act
+		await builder.ExecuteAsync();
+
+		// Assert - singleton path with no query string (no key expression)
+		Assert.Equal("/odata/Me", handler.LastRequestPath);
+		Assert.Empty(handler.LastRequestQuery);
+	}
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_WithSelect_IncludesSelectInUrl()
+	{
+		// Arrange
+		var json = """{"@odata.context":"https://example.com/odata/$metadata#Me","Name":"John"}""";
+		var (builder, handler) = CreateBuilder(ODataVersion.V4, json);
+		builder.Select("Name,Email");
+
+		// Act
+		await builder.ExecuteAsync();
+
+		// Assert
+		Assert.Equal("/odata/Me", handler.LastRequestPath);
+		Assert.Contains("$select=Name,Email", handler.LastRequestQuery);
+	}
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_WithExpand_IncludesExpandInUrl()
+	{
+		// Arrange
+		var json = """{"@odata.context":"...","Name":"John","Address":{"City":"NYC"}}""";
+		var (builder, handler) = CreateBuilder(ODataVersion.V4, json);
+		builder.Expand("Address");
+
+		// Act
+		await builder.ExecuteAsync();
+
+		// Assert
+		Assert.Equal("/odata/Me", handler.LastRequestPath);
+		Assert.Contains("$expand=", handler.LastRequestQuery);
+		Assert.Contains("Address", handler.LastRequestQuery);
+	}
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_WithSelectAndExpand_IncludesBothInUrl()
+	{
+		// Arrange
+		var json = """{"@odata.context":"...","Name":"John","Address":{"City":"NYC"}}""";
+		var (builder, handler) = CreateBuilder(ODataVersion.V4, json);
+		builder.Select("Name").Expand("Address");
+
+		// Act
+		await builder.ExecuteAsync();
+
+		// Assert
+		Assert.Equal("/odata/Me", handler.LastRequestPath);
+		Assert.Contains("$select=Name", handler.LastRequestQuery);
+		Assert.Contains("$expand=", handler.LastRequestQuery);
+	}
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_DoesNotAppendKeyExpression()
+	{
+		// Arrange - singletons have no key, so the URL must NOT contain "(..."
+		var json = """{"@odata.context":"...","ID":1,"Name":"John"}""";
+		var (builder, handler) = CreateBuilder(ODataVersion.V4, json);
+
+		// Act
+		await builder.ExecuteAsync();
+
+		// Assert - no parentheses for key
+		Assert.DoesNotContain("(", handler.LastRequestPath);
+	}
+
+	#endregion
+
+	#region Deserialization Tests
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_V4Response_DeserializesCorrectly()
+	{
+		// Arrange - OData V4 singleton response (entity at root, no "value" wrapper)
+		var json = """{"@odata.context":"https://example.com/odata/$metadata#Me","ID":42,"Name":"Jane Doe","Email":"jane@example.com"}""";
+		var (builder, _) = CreateBuilder(ODataVersion.V4, json);
+
+		// Act
+		var result = await builder.ExecuteAsync();
+
+		// Assert
+		Assert.NotNull(result);
+		Assert.Equal(42, result.ID);
+		Assert.Equal("Jane Doe", result.Name);
+		Assert.Equal("jane@example.com", result.Email);
+	}
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_V4ResponseWithExpand_DeserializesNestedEntity()
+	{
+		// Arrange
+		var json = """{"@odata.context":"...","ID":1,"Name":"John","Address":{"City":"Seattle"}}""";
+		var (builder, _) = CreateBuilder(ODataVersion.V4, json);
+		builder.Expand("Address");
+
+		// Act
+		var result = await builder.ExecuteAsync();
+
+		// Assert
+		Assert.NotNull(result);
+		Assert.Equal(1, result.ID);
+		Assert.Equal("John", result.Name);
+		Assert.NotNull(result.Address);
+		Assert.Equal("Seattle", result.Address.City);
+	}
+
+	[Fact]
+	public async Task SingletonBuilder_ExecuteAsync_NotFound_ReturnsNull()
+	{
+		// Arrange
+		var (builder, _) = CreateBuilder(ODataVersion.V4, "", HttpStatusCode.NotFound);
+
+		// Act
+		var result = await builder.ExecuteAsync();
+
+		// Assert
+		Assert.Null(result);
+	}
+
+	#endregion
+
+	/// <summary>
+	/// A simple HTTP handler that captures request details and returns a fixed response.
+	/// </summary>
+	private class MockHttpHandler(string responseBody, HttpStatusCode statusCode = HttpStatusCode.OK) : HttpMessageHandler
+	{
+		public string LastRequestPath { get; private set; } = "";
+		public string LastRequestQuery { get; private set; } = "";
+
+		protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+		{
+			LastRequestPath = request.RequestUri?.AbsolutePath ?? "";
+			LastRequestQuery = request.RequestUri?.Query ?? "";
+
+			return Task.FromResult(new HttpResponseMessage(statusCode)
+			{
+				Content = new StringContent(responseBody, System.Text.Encoding.UTF8, "application/json")
+			});
+		}
+	}
+}