Added header handler tests

tests/PinguApps.Appwrite.Client.Tests/Handlers/HeaderHandlerTests.cs

@@ -0,0 +1,42 @@
+using Moq;
+using Moq.Protected;
+using PinguApps.Appwrite.Client.Handlers;
+using PinguApps.Appwrite.Shared.Tests;
+
+namespace PinguApps.Appwrite.Client.Tests.Handlers;
+public class HeaderHandlerTests
+{
+    [Fact]
+    public async Task SendAsync_AddsRequiredHeaders()
+    {
+        // Arrange
+        var mockInnerHandler = new Mock<HttpMessageHandler>();
+        mockInnerHandler.Protected()
+            .Setup<Task<HttpResponseMessage>>(
+                "SendAsync",
+                ItExpr.IsAny<HttpRequestMessage>(),
+                ItExpr.IsAny<CancellationToken>()
+            )
+            .ReturnsAsync(new HttpResponseMessage())
+            .Verifiable();
+
+        var headerHandler = new HeaderHandler(Constants.ProjectId)
+        {
+            InnerHandler = mockInnerHandler.Object
+        };
+        var httpClient = new HttpClient(headerHandler);
+
+        // Act
+        await httpClient.SendAsync(new HttpRequestMessage(HttpMethod.Get, "http://test.com"));
+
+        // Assert
+        mockInnerHandler.Protected().Verify(
+            "SendAsync",
+            Times.Once(),
+            ItExpr.Is<HttpRequestMessage>(req =>
+                req.Headers.Contains("x-appwrite-project") &&
+                req.Headers.GetValues("x-appwrite-project").Contains(Constants.ProjectId)),
+            ItExpr.IsAny<CancellationToken>()
+        );
+    }
+}