From 58dcb6a0777abc4ab38ae358b79364520b478818 Mon Sep 17 00:00:00 2001
From: "Tomohisa Tanaka (Maroontress)" <Tomohisa.Tanaka@gmail.com>
Date: Fri, 15 Mar 2019 22:54:13 +0900
Subject: [PATCH] Fix EqualsNull code fix to keep EndOfLineTrivia. (#99)

---
 .../Refactoring/EqualsNull/Code.cs            | 10 +++++
 .../Refactoring/EqualsNull/CodeFix.cs         |  9 +++++
 .../Refactoring/IsNull/Code.cs                | 10 +++++
 .../Refactoring/IsNull/CodeFix.cs             |  9 +++++
 .../Refactoring/EqualsNull/CodeFixer.cs       | 38 +++++++++++++------
 5 files changed, 64 insertions(+), 12 deletions(-)

diff --git a/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/Code.cs b/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/Code.cs
index b5e3f4a3..7c1e5950 100644
--- a/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/Code.cs
+++ b/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/Code.cs
@@ -28,5 +28,15 @@ public void NullableValueType(int? value)
                 return;
             }
         }
+
+        public void EndOfLineTrivia(object value)
+        {
+            if (value != null
+            //@ ^!=
+                && value.ToString() == "")
+            {
+                return;
+            }
+        }
     }
 }
diff --git a/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/CodeFix.cs b/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/CodeFix.cs
index 96ebe4be..d3e12456 100644
--- a/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/CodeFix.cs
+++ b/StyleChecker/StyleChecker.Test/Refactoring/EqualsNull/CodeFix.cs
@@ -25,5 +25,14 @@ public void NullableValueType(int? value)
                 return;
             }
         }
+
+        public void EndOfLineTrivia(object value)
+        {
+            if (!(value is null)
+                && value.ToString() == "")
+            {
+                return;
+            }
+        }
     }
 }
diff --git a/StyleChecker/StyleChecker.Test/Refactoring/IsNull/Code.cs b/StyleChecker/StyleChecker.Test/Refactoring/IsNull/Code.cs
index 3972d384..0655b088 100644
--- a/StyleChecker/StyleChecker.Test/Refactoring/IsNull/Code.cs
+++ b/StyleChecker/StyleChecker.Test/Refactoring/IsNull/Code.cs
@@ -37,5 +37,15 @@ public void KeepTrivia(string value)
                 return;
             }
         }
+
+        public void EndOfLineTrivia(object value)
+        {
+            if (!(value is null)
+            //@ ^!=
+                && value.ToString() == "")
+            {
+                return;
+            }
+        }
     }
 }
diff --git a/StyleChecker/StyleChecker.Test/Refactoring/IsNull/CodeFix.cs b/StyleChecker/StyleChecker.Test/Refactoring/IsNull/CodeFix.cs
index 63df366f..a9e27894 100644
--- a/StyleChecker/StyleChecker.Test/Refactoring/IsNull/CodeFix.cs
+++ b/StyleChecker/StyleChecker.Test/Refactoring/IsNull/CodeFix.cs
@@ -33,5 +33,14 @@ public void KeepTrivia(string value)
                 return;
             }
         }
+
+        public void EndOfLineTrivia(object value)
+        {
+            if (value != null
+                && value.ToString() == "")
+            {
+                return;
+            }
+        }
     }
 }
diff --git a/StyleChecker/StyleChecker/Refactoring/EqualsNull/CodeFixer.cs b/StyleChecker/StyleChecker/Refactoring/EqualsNull/CodeFixer.cs
index 5cfa8558..523d71b9 100644
--- a/StyleChecker/StyleChecker/Refactoring/EqualsNull/CodeFixer.cs
+++ b/StyleChecker/StyleChecker/Refactoring/EqualsNull/CodeFixer.cs
@@ -84,23 +84,37 @@ private static async Task<Solution> Replace(
             var root = await document.GetSyntaxRootAsync(cancellationToken)
                 .ConfigureAwait(false);
 
-            var newNode = SyntaxFactory.IsPatternExpression(
-                node.Left,
-                SyntaxFactory.Token(SyntaxKind.IsKeyword)
-                    .WithTriviaFrom(node.OperatorToken),
-                SyntaxFactory.ConstantPattern(
-                    SyntaxFactory.LiteralExpression(
-                        SyntaxKind.NullLiteralExpression))
-                    .WithTriviaFrom(node.Right)) as ExpressionSyntax;
+            var right = node.Right;
+            var @null = SyntaxFactory.ConstantPattern(
+                SyntaxFactory.LiteralExpression(
+                    SyntaxKind.NullLiteralExpression));
+            var @is = SyntaxFactory.Token(SyntaxKind.IsKeyword)
+                .WithTriviaFrom(node.OperatorToken);
 
-            if (node.OperatorToken.Kind()
-                == SyntaxKind.ExclamationEqualsToken)
+            ExpressionSyntax NewEqualNode()
             {
-                newNode = SyntaxFactory.PrefixUnaryExpression(
+                return SyntaxFactory.IsPatternExpression(
+                    node.Left,
+                    @is,
+                    @null.WithTriviaFrom(right));
+            }
+
+            ExpressionSyntax NewNotEqualNode()
+            {
+                var n = SyntaxFactory.IsPatternExpression(
+                    node.Left,
+                    @is,
+                    @null.WithLeadingTrivia(right.GetLeadingTrivia()));
+                return SyntaxFactory.PrefixUnaryExpression(
                     SyntaxKind.LogicalNotExpression,
-                    SyntaxFactory.ParenthesizedExpression(newNode));
+                    SyntaxFactory.ParenthesizedExpression(n)
+                        .WithTrailingTrivia(right.GetTrailingTrivia()));
             }
 
+            var newNode = (node.OperatorToken.Kind()
+                    == SyntaxKind.ExclamationEqualsToken)
+                ? NewNotEqualNode()
+                : NewEqualNode();
             newNode = newNode.WithTriviaFrom(node);
 
             var newRoot = root.ReplaceNode(node, newNode);