feat: Add BadRequest and UnprocessableEntity exception handling in ExceptionHelper

Author: mpartipilo

src/Weaviate.Client.Tests/Unit/ExceptionHelperTests.cs

@@ -273,4 +273,46 @@ public void MapGrpcException_VectorizationError_ReturnsExternalModuleProblemExce
         // Assert
         Assert.IsType<WeaviateExternalModuleProblemException>(result);
     }
+
+    [Fact]
+    public void MapHttpException_BadRequest_ReturnsBadRequestException()
+    {
+        // Arrange
+        var innerEx = new Weaviate.Client.Rest.WeaviateUnexpectedStatusCodeException(
+            HttpStatusCode.BadRequest,
+            new HashSet<HttpStatusCode> { HttpStatusCode.OK },
+            "Bad request"
+        );
+
+        // Act
+        var result = ExceptionHelper.MapHttpException(
+            HttpStatusCode.BadRequest,
+            "Bad request",
+            innerEx
+        );
+
+        // Assert
+        Assert.IsType<WeaviateBadRequestException>(result);
+    }
+
+    [Fact]
+    public void MapHttpException_UnprocessableEntity_ReturnsUnprocessableEntityException()
+    {
+        // Arrange
+        var innerEx = new Weaviate.Client.Rest.WeaviateUnexpectedStatusCodeException(
+            HttpStatusCode.UnprocessableEntity,
+            new HashSet<HttpStatusCode> { HttpStatusCode.OK },
+            "Unprocessable entity"
+        );
+
+        // Act
+        var result = ExceptionHelper.MapHttpException(
+            HttpStatusCode.UnprocessableEntity,
+            "Unprocessable entity",
+            innerEx
+        );
+
+        // Assert
+        Assert.IsType<WeaviateUnprocessableEntityException>(result);
+    }
 }

src/Weaviate.Client/Errors.cs

@@ -206,13 +206,42 @@ public WeaviateAuthorizationException(string? message = null, Exception? innerEx
         : base(message ?? DefaultMessage, innerException) { }
 }
 
+/// <summary>
+/// Exception thrown when the server cannot process the request due to a client error (HTTP 400 Bad Request).
+/// This can be caused by a malformed request, invalid parameters, or a schema validation error.
+/// </summary>
+public class WeaviateBadRequestException : WeaviateServerException
+{
+    public const string DefaultMessage =
+        "The request is invalid. Please check the request parameters and schema.";
+
+    public WeaviateBadRequestException(string? message = null, Exception? innerException = null)
+        : base(message ?? DefaultMessage, innerException) { }
+}
+
+/// <summary>
+/// Exception thrown when the server understands the content type and syntax of the request,
+/// but it is unable to process the contained instructions (HTTP 422 Unprocessable Entity).
+/// </summary>
+public class WeaviateUnprocessableEntityException : WeaviateServerException
+{
+    public const string DefaultMessage =
+        "The server is unable to process the request. Please check the request content.";
+
+    public WeaviateUnprocessableEntityException(
+        string? message = null,
+        Exception? innerException = null
+    )
+        : base(message ?? DefaultMessage, innerException) { }
+}
+
 /// <summary>
 /// Exception thrown when a collection limit has been reached (HTTP 422 Unprocessable Entity).
 /// This typically occurs when trying to create more collections than allowed by the server configuration.
 /// </summary>
-public class WeaviateCollectionLimitReachedException : WeaviateServerException
+public class WeaviateCollectionLimitReachedException : WeaviateUnprocessableEntityException
 {
-    public const string DefaultMessage =
+    public new const string DefaultMessage =
         "Collection limit reached. Cannot create more collections than allowed by the server configuration.";
 
     public WeaviateCollectionLimitReachedException(
@@ -226,9 +255,9 @@ public WeaviateCollectionLimitReachedException(
 /// Exception thrown when a required module is not available or enabled (HTTP 422 Unprocessable Entity).
 /// This occurs when attempting to use a feature that requires a module that is not configured on the server.
 /// </summary>
-public class WeaviateModuleNotAvailableException : WeaviateServerException
+public class WeaviateModuleNotAvailableException : WeaviateUnprocessableEntityException
 {
-    public const string DefaultMessage =
+    public new const string DefaultMessage =
         "Required module is not available or enabled on the Weaviate server. Please check the server's module configuration.";
 
     public WeaviateModuleNotAvailableException(
@@ -253,5 +282,3 @@ public WeaviateExternalModuleProblemException(
     )
         : base(message ?? DefaultMessage, innerException) { }
 }
-
-// TODO WeaviateBadRequestException

src/Weaviate.Client/ExceptionHelper.cs

@@ -34,6 +34,7 @@ public static WeaviateException MapHttpException(
         // Check status code first
         WeaviateException? exception = statusCode switch
         {
+            HttpStatusCode.BadRequest => new WeaviateBadRequestException(null, innerException),
             HttpStatusCode.Unauthorized => new WeaviateAuthenticationException(
                 null,
                 innerException
@@ -68,6 +69,11 @@ public static WeaviateException MapHttpException(
             }
         }
 
+        if (statusCode == HttpStatusCode.UnprocessableEntity)
+        {
+            return new WeaviateUnprocessableEntityException(null, innerException);
+        }
+
         // Re-throw the original exception if we can't map it
         throw innerException;
     }

src/Weaviate.Client/Rest/Http.cs

@@ -61,9 +61,6 @@ await response.EnsureExpectedStatusCodeAsync(
                 new SortedSet<HttpStatusCode>(expectedCodes),
                 error
             );
-
-            // TODO
-            // HttpStatusCode.BadRequest
         }
         catch (WeaviateUnexpectedStatusCodeException ex)
         {