Add tests for omitted message in connect error

internal/app/connectconformance/testsuites/data/connect_client_error_endstream.yaml

@@ -83,6 +83,26 @@ testCases:
       error:
         code: CODE_UNAVAILABLE
         message: oops
+  - request:
+      # The message property is optional - it can be omitted or be an empty string
+      testName: error/missing-message
+      service: connectrpc.conformance.v1.ConformanceService
+      method: Unary
+      streamType: STREAM_TYPE_UNARY
+      requestMessages:
+        - "@type": type.googleapis.com/connectrpc.conformance.v1.UnaryRequest
+          responseDefinition:
+            rawResponse:
+              statusCode: 401
+              headers:
+                - name: content-type
+                  value: [ "application/json" ]
+              unary:
+                text: |
+                  { "code": "unauthenticated" }
+    expectedResponse:
+      error:
+        code: CODE_UNAUTHENTICATED
   - request:
       testName: error/allow-unrecognized-fields
       service: connectrpc.conformance.v1.ConformanceService
@@ -273,6 +293,31 @@ testCases:
       error:
         code: CODE_UNKNOWN
         message: oops
+  - request:
+      # The message property is optional - it can be omitted or be an empty string
+      testName: end-stream/missing-message
+      service: connectrpc.conformance.v1.ConformanceService
+      method: ServerStream
+      streamType: STREAM_TYPE_SERVER_STREAM
+      requestMessages:
+        - "@type": type.googleapis.com/connectrpc.conformance.v1.ServerStreamRequest
+          responseDefinition:
+            rawResponse:
+              statusCode: 200
+              headers:
+                - name: content-type
+                  value: [ "application/connect+proto" ]
+              stream:
+                items:
+                  - flags: 2
+                    payload:
+                      text: |
+                        {
+                          "error": { "code": "unauthenticated" }
+                        }
+    expectedResponse:
+      error:
+        code: CODE_UNAUTHENTICATED
   - request:
       testName: end-stream/allow-unrecognized-fields
       service: connectrpc.conformance.v1.ConformanceService