yak shaving (code analysis fixes)

Author: mgravell

src/protobuf-net.Grpc/Internal/ContractOperation.cs

@@ -316,18 +316,11 @@ where method.IsGenericMethodDefinition
             {(MethodType.Unary, ResultKind.Sync, VoidKind.Response), nameof(Reshape.UnarySyncVoid) },
         };
 #pragma warning restore CS0618
-        private string? GetClientHelperName()
+        private string? GetClientHelperName() => Context switch
         {
-            switch (Context)
-            {
-                case ContextKind.CallContext:
-                case ContextKind.NoContext:
-                case ContextKind.CancellationToken:
-                    return _clientResponseMap.TryGetValue((MethodType, Result, Void & VoidKind.Response), out var helper) ? helper : null;
-                default:
-                    return null;
-            }
-        }
+            ContextKind.CallContext or ContextKind.NoContext or ContextKind.CancellationToken => _clientResponseMap.TryGetValue((MethodType, Result, Void & VoidKind.Response), out var helper) ? helper : null,
+            _ => null,
+        };
 
 
         internal bool IsSyncT()

tests/protobuf-net.Grpc.Test.Integration/StreamTests.cs

@@ -780,8 +780,10 @@ public async Task FullDuplexAsync(int send, int produce, int stopReadingAfter =
         {
             await using var svc = CreateClient(out var client);
 
-            var reqHeaders = new Metadata();
-            reqHeaders.Add("produce", produce);
+            var reqHeaders = new Metadata
+            {
+                { "produce", produce }
+            };
             if (byItem) reqHeaders.Add("mode", "byitem");
             if (stopReadingAfter >= 0) reqHeaders.Add("stop", stopReadingAfter);
 

tests/protobuf-net.Grpc.Test/Issues/Issue87.cs

@@ -17,9 +17,9 @@ protected override bool TryBind<TService, TRequest, TResponse>(ServiceBindContex
             return true;
         }
         protected internal override void OnWarn(string message, object?[]? args = null)
-            => Warnings.Add(string.Format(message, args));
+            => Warnings.Add(string.Format(message, args ?? Array.Empty<object>()));
         protected internal override void OnError(string message, object?[]? args = null)
-            => Errors.Add(string.Format(message, args));
+            => Errors.Add(string.Format(message, args ?? Array.Empty<object>()));
     }
 
     public class Issue87