Issue #1665: added null validation (#1666)

Co-authored-by: James Newton-King <[email protected]>

Author: brunomartinspro

src/dotnet-grpc/Commands/CommandBase.cs

@@ -174,7 +174,13 @@ public void AddProtobufReference(Services services, string additionalImportDirs,
             }
 
             var normalizedFile = NormalizePath(file);
-            var normalizedAdditionalImportDirs = string.Join(';', additionalImportDirs.Split(';', StringSplitOptions.RemoveEmptyEntries).Select(NormalizePath));
+            
+            var normalizedAdditionalImportDirs = string.Empty;
+
+            if (!string.IsNullOrWhiteSpace(additionalImportDirs))
+            {
+                normalizedAdditionalImportDirs = string.Join(';', additionalImportDirs.Split(';', StringSplitOptions.RemoveEmptyEntries).Select(NormalizePath));
+            }
 
             if (!Project.GetItems(ProtobufElement).Any(i => string.Equals(NormalizePath(i.UnevaluatedInclude), normalizedFile, StringComparison.OrdinalIgnoreCase)))
             {

test/dotnet-grpc.Tests/CommandBaseTests.cs

@@ -267,6 +267,32 @@ public void AddProtobufReference_AdditionalImportDirs(string additionalImportDir
             Assert.False(protoRef.HasMetadata(CommandBase.LinkElement));
         }
 
+
+        [Test]
+        public void AddProtobufReference_Without_AdditionalImportDirs()
+        {
+            // Arrange
+            var commandBase = new CommandBase(
+                new TestConsole(),
+                CreateIsolatedProject(Path.Combine(Directory.GetCurrentDirectory(), "TestAssets", "EmptyProject", "test.csproj")));
+
+            const string proto = "Proto/a.proto";
+            
+            // Act
+            commandBase.AddProtobufReference(Services.Server, null!, Access.Internal, proto, SourceUrl);
+            commandBase.Project.ReevaluateIfNecessary();
+
+            // Assert
+            var protoRefs = commandBase.Project.GetItems(CommandBase.ProtobufElement);
+            Assert.AreEqual(1, protoRefs.Count);
+            var protoRef = protoRefs.Single();
+            Assert.AreEqual(proto.Replace('/', '\\'), protoRef.UnevaluatedInclude);
+            Assert.AreEqual("Server", protoRef.GetMetadataValue(CommandBase.GrpcServicesElement));
+            Assert.AreEqual("Internal", protoRef.GetMetadataValue(CommandBase.AccessElement));
+            Assert.AreEqual(SourceUrl, protoRef.GetMetadataValue(CommandBase.SourceUrlElement));
+            Assert.False(protoRef.HasMetadata(CommandBase.LinkElement));
+        }
+
         static object[] DoesNotOverwriteCases()
         {
             var cases = new List<object>