TSQL Formatter Service (#229)

- TSqlFormatterService with support for formatting document and text range inside document
- Settings support for all formatting options.
- Extensibility support so that the service can be initialized using MEF extensibility, and can find all necessary TSqlFormatters using the same process

Fix Initialize request error on startup
- Messages were being read from the input channel before all request handlers were registered
- In particular, the Initialize request which is key for any server to talk to the client was getting lost because the message reader thread begins consuming, and we take an extra few hundred milliseconds due to MEF startup before we register the handler
- The solution is to initialize the message handler so request handlers can register, but not actually start processing incoming messages until all handers are ready. This is a safer way to go and should improve reliability overall

Improvements from internal prototype:
- Normalizing baselines to handle the line ending differences on Mac & Linux vs. Windows
- Significantly shortened most lines by implementing base class methods to wrap common objects from Visitor.Context and removing unnecessary "this." syntax
- Refactored the SqlCommonTableExpressionFormatter and related classes to reduce code count significantly. This provides a pattern to follow when refactoring other classes for similar clarity. It's likely a lot of common logic could be found and reused across these.
- Reduced overall code size by adding utility methods

test/Microsoft.SqlTools.ServiceLayer.Test/Credentials/CredentialServiceTests.cs

@@ -81,7 +81,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
             var contextMock = RequestContextMocks.Create<bool>(null).AddErrorHandling(obj => errorResponse = obj);
 
             await service.HandleSaveCredentialRequest(new Credential(null), contextMock.Object);
-            VerifyErrorSent(contextMock);
+            TestUtils.VerifyErrorSent(contextMock);
             Assert.True(((string)errorResponse).Contains("ArgumentException"));
         }
 
@@ -92,14 +92,14 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
             var contextMock = RequestContextMocks.Create<bool>(null).AddErrorHandling(obj => errorResponse = obj);
             
             await service.HandleSaveCredentialRequest(new Credential(credentialId), contextMock.Object);
-            VerifyErrorSent(contextMock);
+            TestUtils.VerifyErrorSent(contextMock);
             Assert.True(((string)errorResponse).Contains("ArgumentException"));
         }
         
         [Fact]
         public async Task SaveCredentialWorksForSingleCredential()
         {
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password1), requestContext),
                 verify: (actual => Assert.True(actual)));
         }
@@ -107,11 +107,11 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         [Fact]
         public async Task SaveCredentialSupportsSavingCredentialMultipleTimes()
         {
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password1), requestContext),
                 verify: (actual => Assert.True(actual)));
 
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password1), requestContext),
                 verify: (actual => Assert.True(actual)));
         }
@@ -120,13 +120,13 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         public async Task ReadCredentialWorksForSingleCredential()
         {
             // Given we have saved the credential
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password1), requestContext),
                 verify: (actual => Assert.True(actual, "Expect Credential to be saved successfully")));
 
 
             // Expect read of the credential to return the password
-            await RunAndVerify<Credential>(
+            await TestUtils.RunAndVerify<Credential>(
                 test: (requestContext) => service.HandleReadCredentialRequest(new Credential(credentialId, null), requestContext),
                 verify: (actual =>
                 {
@@ -139,22 +139,22 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         {
 
             // Given we have saved multiple credentials
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password1), requestContext),
                 verify: (actual => Assert.True(actual, "Expect Credential to be saved successfully")));
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(otherCredId, otherPassword), requestContext),
                 verify: (actual => Assert.True(actual, "Expect Credential to be saved successfully")));
 
 
             // Expect read of the credentials to return the right password
-            await RunAndVerify<Credential>(
+            await TestUtils.RunAndVerify<Credential>(
                 test: (requestContext) => service.HandleReadCredentialRequest(new Credential(credentialId, null), requestContext),
                 verify: (actual =>
                 {
                     Assert.Equal(password1, actual.Password);
                 }));
-            await RunAndVerify<Credential>(
+            await TestUtils.RunAndVerify<Credential>(
                 test: (requestContext) => service.HandleReadCredentialRequest(new Credential(otherCredId, null), requestContext),
                 verify: (actual =>
                 {
@@ -166,17 +166,17 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         public async Task ReadCredentialHandlesPasswordUpdate()
         {
             // Given we have saved twice with a different password
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password1), requestContext),
                 verify: (actual => Assert.True(actual)));
 
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password2), requestContext),
                verify: (actual => Assert.True(actual)));
 
             // When we read the value for this credential
             // Then we expect only the last saved password to be found
-            await RunAndVerify<Credential>(
+            await TestUtils.RunAndVerify<Credential>(
                 test: (requestContext) => service.HandleReadCredentialRequest(new Credential(credentialId), requestContext),
                 verify: (actual =>
                 {
@@ -192,7 +192,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
 
             // Verify throws on null, and this is sent as an error
             await service.HandleReadCredentialRequest(null, contextMock.Object);
-            VerifyErrorSent(contextMock);
+            TestUtils.VerifyErrorSent(contextMock);
             Assert.True(((string)errorResponse).Contains("ArgumentNullException"));            
         }
         
@@ -204,7 +204,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
 
             // Verify throws with no ID
             await service.HandleReadCredentialRequest(new Credential(), contextMock.Object);
-            VerifyErrorSent(contextMock);
+            TestUtils.VerifyErrorSent(contextMock);
             Assert.True(((string)errorResponse).Contains("ArgumentException"));
         }
 
@@ -216,7 +216,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
             
             // When reading the credential
             // Then expect the credential to be returned but password left blank
-            await RunAndVerify<Credential>(
+            await TestUtils.RunAndVerify<Credential>(
                 test: (requestContext) => service.HandleReadCredentialRequest(new Credential(credWithNoPassword, null), requestContext),
                 verify: (actual =>
                 {
@@ -234,7 +234,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
 
             // Verify throws with no ID
             await service.HandleDeleteCredentialRequest(new Credential(), contextMock.Object);
-            VerifyErrorSent(contextMock);
+            TestUtils.VerifyErrorSent(contextMock);
             Assert.True(((string)errorResponse).Contains("ArgumentException"));
         }
 
@@ -242,49 +242,21 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Connection
         public async Task DeleteCredentialReturnsTrueOnlyIfCredentialExisted()
         {
             // Save should be true
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleSaveCredentialRequest(new Credential(credentialId, password1), requestContext),
                 verify: (actual => Assert.True(actual)));
 
             // Then delete - should return true
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                 test: (requestContext) => service.HandleDeleteCredentialRequest(new Credential(credentialId), requestContext),
                 verify: (actual => Assert.True(actual)));
 
             // Then delete - should return false as no longer exists
-            await RunAndVerify<bool>(
+            await TestUtils.RunAndVerify<bool>(
                test: (requestContext) => service.HandleDeleteCredentialRequest(new Credential(credentialId), requestContext),
                verify: (actual => Assert.False(actual)));
         }
 
-        private async Task RunAndVerify<T>(Func<RequestContext<T>, Task> test, Action<T> verify)
-        {
-            T result = default(T);
-            var contextMock = RequestContextMocks.Create<T>(r => result = r).AddErrorHandling(null);
-            await test(contextMock.Object);
-            VerifyResult(contextMock, verify, result);
-        }
-
-        private void VerifyErrorSent<T>(Mock<RequestContext<T>> contextMock)
-        {
-            contextMock.Verify(c => c.SendResult(It.IsAny<T>()), Times.Never);
-            contextMock.Verify(c => c.SendError(It.IsAny<string>()), Times.Once);
-        }
-
-        private void VerifyResult<T, U>(Mock<RequestContext<T>> contextMock, U expected, U actual)
-        {
-            contextMock.Verify(c => c.SendResult(It.IsAny<T>()), Times.Once);
-            Assert.Equal(expected, actual);
-            contextMock.Verify(c => c.SendError(It.IsAny<string>()), Times.Never);
-        }
-
-        private void VerifyResult<T>(Mock<RequestContext<T>> contextMock, Action<T> verify, T actual)
-        {
-            contextMock.Verify(c => c.SendResult(It.IsAny<T>()), Times.Once);
-            contextMock.Verify(c => c.SendError(It.IsAny<string>()), Times.Never);
-            verify(actual);
-        }
-
     }
 }