tests: add tests for sad path in new files methods

tests/AnthropicClient.Tests/Integration/AnthropicApiClientTests.cs

@@ -1966,6 +1966,33 @@ public class AnthropicApiClientTests : IntegrationTest
     });
   }
 
+  [Fact]
+  public async Task CreateFileAsync_WhenCalledAndRequestFails_ItShouldReturnError()
+  {
+    _mockHttpMessageHandler
+      .WhenCreateFileRequest()
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{
+            ""type"": ""error"",
+            ""error"": {
+              ""type"": ""invalid_request_error"",
+              ""message"": ""file: file size exceeds limit""
+            }
+          }"
+      );
+
+    var fileContent = new MemoryStream(Encoding.UTF8.GetBytes("Example file content"));
+    var request = new CreateFileRequest(fileContent, "example.txt", "text/plain");
+
+    var result = await Client.CreateFileAsync(request);
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<InvalidRequestError>();
+  }
+
   [Fact]
   public async Task ListFilesAsync_WhenCalled_ItShouldReturnPageOfFiles()
   {
@@ -2014,6 +2041,30 @@ public class AnthropicApiClientTests : IntegrationTest
     });
   }
 
+  [Fact]
+  public async Task ListFilesAsync_WhenCalledAndRequestFails_ItShouldReturnError()
+  {
+    _mockHttpMessageHandler
+      .WhenListFilesRequest()
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{
+            ""type"": ""error"",
+            ""error"": {
+              ""type"": ""invalid_request_error"",
+              ""message"": ""files: file not found""
+            }
+          }"
+      );
+
+    var result = await Client.ListFilesAsync();
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<InvalidRequestError>();
+  }
+
   [Fact]
   public async Task ListFilesAsync_WhenCalledWithPagingRequest_ItShouldReturnPageOfFiles()
   {
@@ -2204,6 +2255,32 @@ public class AnthropicApiClientTests : IntegrationTest
     });
   }
 
+  [Fact]
+  public async Task GetFileInfoAsync_WhenCalledAndRequestFails_ItShouldReturnError()
+  {
+    var fileId = "file_013Zva2CMHLNnXjNJJKqJ2EF";
+
+    _mockHttpMessageHandler
+      .WhenGetFileRequest(fileId)
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{
+            ""type"": ""error"",
+            ""error"": {
+              ""type"": ""invalid_request_error"",
+              ""message"": ""file: file not found""
+            }
+          }"
+      );
+
+    var result = await Client.GetFileInfoAsync(fileId);
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<InvalidRequestError>();
+  }
+
   [Fact]
   public async Task GetFileAsync_WhenCalled_ItShouldReturnFileContent()
   {
@@ -2228,6 +2305,32 @@ public class AnthropicApiClientTests : IntegrationTest
     content.Should().Be("Example file content");
   }
 
+  [Fact]
+  public async Task GetFileAsync_WhenCalledAndRequestFails_ItShouldReturnError()
+  {
+    var fileId = "file_013Zva2CMHLNnXjNJJKqJ2EF";
+
+    _mockHttpMessageHandler
+      .WhenGetFileContentRequest(fileId)
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{
+            ""type"": ""error"",
+            ""error"": {
+              ""type"": ""invalid_request_error"",
+              ""message"": ""file: file not found""
+            }
+          }"
+      );
+
+    var result = await Client.GetFileAsync(fileId);
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<InvalidRequestError>();
+  }
+
   [Fact]
   public async Task DeleteFileAsync_WhenCalled_ItShouldReturnDeletionResponse()
   {
@@ -2251,4 +2354,30 @@ public class AnthropicApiClientTests : IntegrationTest
     result.Value.Id.Should().Be(fileId);
     result.Value.Type.Should().Be("file_deleted");
   }
+
+  [Fact]
+  public async Task DeleteFileAsync_WhenCalledAndRequestFails_ItShouldReturnError()
+  {
+    var fileId = "file_013Zva2CMHLNnXjNJJKqJ2EF";
+
+    _mockHttpMessageHandler
+      .WhenDeleteFileRequest(fileId)
+      .Respond(
+        HttpStatusCode.BadRequest,
+        "application/json",
+        @"{
+            ""type"": ""error"",
+            ""error"": {
+              ""type"": ""invalid_request_error"",
+              ""message"": ""file: file not found""
+            }
+          }"
+      );
+
+    var result = await Client.DeleteFileAsync(fileId);
+
+    result.IsSuccess.Should().BeFalse();
+    result.Error.Should().BeOfType<AnthropicError>();
+    result.Error.Error.Should().BeOfType<InvalidRequestError>();
+  }
 }