Add more rules

Author: Lakshmi Priya Sekar

src/Microsoft.DotNet.CodeFormatting/Microsoft.DotNet.CodeFormatting.csproj

@@ -79,7 +79,8 @@
     <Compile Include="Filters\IgnoreDesignerGeneratedCodeFilter.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Rules\HasCopyrightHeaderFormattingRule.cs" />
-    <Compile Include="Rules\HasNewLinesAtStartOfDocumentFormattingRule.cs" />
+    <Compile Include="Rules\HasNewLineBeforeFirstNamespaceFormattingRule.cs" />
+    <Compile Include="Rules\HasNewLineBeforeFirstUsingFormattingRule.cs" />
     <Compile Include="Rules\HasNoNewLineAfterOpenBraceFormattingRule.cs" />
     <Compile Include="Rules\HasNoNewLineBeforeEndBraceFormattingRule.cs" />
     <Compile Include="Rules\HasNoXmlBasedCopyrightHeaderFormattingRule.cs" />

src/Microsoft.DotNet.CodeFormatting/Rules/HasNewLineBeforeFirstNamespaceFormattingRule.cs

@@ -0,0 +1,57 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under MIT. See LICENSE in the project root for license information.
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.Composition;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace Microsoft.DotNet.CodeFormatting.Rules
+{
+    [Export(typeof(IFormattingRule))]
+    internal sealed class HasNewLineBeforeFirstNamespaceFormattingRule : IFormattingRule
+    {
+        public async Task<Document> ProcessAsync(Document document, CancellationToken cancellationToken)
+        {
+            var syntaxRoot = await document.GetSyntaxRootAsync(cancellationToken) as CSharpSyntaxNode;
+            if (syntaxRoot == null)
+                return document;
+
+            var firstNamespace = syntaxRoot.DescendantNodesAndSelf().OfType<NamespaceDeclarationSyntax>().FirstOrDefault();
+            IEnumerable<SyntaxTrivia> newTrivia = Enumerable.Empty<SyntaxTrivia>();
+
+            if (firstNamespace == null)
+                return document;
+
+            if (firstNamespace.HasLeadingTrivia)
+            {
+                var trivia = firstNamespace.GetLeadingTrivia();
+                if (trivia.Last().CSharpKind() == SyntaxKind.EndOfLineTrivia)
+                {
+                    int index = trivia.Count - 2;
+                    while (index >= 0)
+                    {
+                        if (trivia.ElementAt(index).CSharpKind() != SyntaxKind.EndOfLineTrivia)
+                            break;
+                        index--;
+                    }
+
+                    newTrivia = trivia.Take(index + 1);
+                }
+                else
+                {
+                    newTrivia = trivia;
+                }
+            }
+
+            newTrivia = newTrivia.Concat(new[] { SyntaxFactory.EndOfLine("\n"), SyntaxFactory.EndOfLine("\n") });
+
+            return document.WithSyntaxRoot(syntaxRoot.ReplaceNode(firstNamespace, firstNamespace.WithLeadingTrivia(newTrivia)));
+        }
+    }
+}

src/Microsoft.DotNet.CodeFormatting/Rules/HasNewLinesAtStartOfDocumentFormattingRule.cs

@@ -24,11 +24,11 @@ public async Task<Document> ProcessAsync(Document document, CancellationToken ca
             var openBraceTokens = syntaxRoot.DescendantTokens().Where((token) => token.CSharpKind() == SyntaxKind.OpenBraceToken);
             Func<SyntaxToken, SyntaxToken, SyntaxToken> replacementForTokens = (token, dummy) =>
             {
-                var triviaItem = token.LeadingTrivia.First();
                 int elementsToRemove = 1;
                 if (token.LeadingTrivia.Count > 1)
                 {
-                    while (triviaItem == token.LeadingTrivia.ElementAt(elementsToRemove))
+                    while (elementsToRemove < token.LeadingTrivia.Count &&
+                            token.LeadingTrivia.ElementAt(elementsToRemove).CSharpKind() == SyntaxKind.EndOfLineTrivia)
                         elementsToRemove++;
                 }
 

src/Microsoft.DotNet.CodeFormatting/Rules/HasNoNewLineAfterOpenBraceFormattingRule.cs

@@ -24,11 +24,11 @@ public async Task<Document> ProcessAsync(Document document, CancellationToken ca
             var closeBraceTokens = syntaxRoot.DescendantTokens().Where((token) => token.CSharpKind() == SyntaxKind.CloseBraceToken);
             Func<SyntaxToken, SyntaxToken, SyntaxToken> replacementForTokens = (token, dummy) =>
             {
-                var triviaItem = token.LeadingTrivia.First();
                 int elementsToRemove = 1;
                 if (token.LeadingTrivia.Count > 1)
                 {
-                    while (triviaItem == token.LeadingTrivia.ElementAt(elementsToRemove))
+                    while (elementsToRemove < token.LeadingTrivia.Count && 
+                            token.LeadingTrivia.ElementAt(elementsToRemove).CSharpKind() == SyntaxKind.EndOfLineTrivia)
                         elementsToRemove++;
                 }