Added command-line tests for SharedCompilationId (no changes expected)

src/Compilers/Core/MSBuildTask/ManagedCompiler.cs

@@ -469,7 +469,7 @@ protected override int ExecuteTool(string pathToTool, string responseFileCommand
 
                     var responseTask = BuildServerConnection.RunServerCompilation(
                         Language,
-                        SharedCompilationId == "" ? null : SharedCompilationId,
+                        string.IsNullOrEmpty(SharedCompilationId) ? null : SharedCompilationId,
                         GetArguments(commandLineCommands, responseFileCommands).ToList(),
                         buildPaths,
                         keepAlive: null,

src/Compilers/Core/MSBuildTaskTests/CscTests.cs

@@ -313,5 +313,26 @@ public void RefOnly()
             csc.RefOnly = true;
             Assert.Equal("/out:test.exe /refonly test.cs", csc.GenerateResponseFileContents());
         }
+
+        [Fact]
+        public void SharedCompilationId()
+        {
+            var csc = new Csc();
+            csc.Sources = MSBuildUtil.CreateTaskItems("test.cs");
+            csc.UseSharedCompilation = true;
+            csc.SharedCompilationId = "testPipeName";
+            Assert.Equal("/out:test.exe test.cs", csc.GenerateResponseFileContents());
+
+            csc = new Csc();
+            csc.Sources = MSBuildUtil.CreateTaskItems("test.cs");
+            csc.UseSharedCompilation = false;
+            csc.SharedCompilationId = "testPipeName";
+            Assert.Equal("/out:test.exe test.cs", csc.GenerateResponseFileContents());
+
+            csc = new Csc();
+            csc.Sources = MSBuildUtil.CreateTaskItems("test.cs");
+            csc.SharedCompilationId = "testPipeName";
+            Assert.Equal("/out:test.exe test.cs", csc.GenerateResponseFileContents());
+        }
     }
 }

src/Compilers/Core/MSBuildTaskTests/VbcTests.cs

@@ -310,5 +310,26 @@ public void RefOnly()
             vbc.RefOnly = true;
             Assert.Equal("/optionstrict:custom /out:test.exe /refonly test.vb", vbc.GenerateResponseFileContents());
         }
+
+        [Fact]
+        public void SharedCompilationId()
+        {
+            var vbc = new Vbc();
+            vbc.Sources = MSBuildUtil.CreateTaskItems("test.vb");
+            vbc.UseSharedCompilation = true;
+            vbc.SharedCompilationId = "testPipeName";
+            Assert.Equal("/optionstrict:custom /out:test.exe test.vb", vbc.GenerateResponseFileContents());
+
+            vbc = new Vbc();
+            vbc.Sources = MSBuildUtil.CreateTaskItems("test.vb");
+            vbc.UseSharedCompilation = false;
+            vbc.SharedCompilationId = "testPipeName";
+            Assert.Equal("/optionstrict:custom /out:test.exe test.vb", vbc.GenerateResponseFileContents());
+
+            vbc = new Vbc();
+            vbc.Sources = MSBuildUtil.CreateTaskItems("test.vb");
+            vbc.SharedCompilationId = "testPipeName";
+            Assert.Equal("/optionstrict:custom /out:test.exe test.vb", vbc.GenerateResponseFileContents());
+        }
     }
 }