Merge pull request #4771 from diryboy/FixBinaryOperatorFormatting2

Fix binary expression formatting

src/Workspaces/CSharp/Portable/Formatting/Rules/SpacingFormattingRule.cs

@@ -253,7 +253,18 @@ public override AdjustSpacesOperation GetAdjustSpacesOperation(SyntaxToken previ
                     case BinaryOperatorSpacingOptions.Single:
                         return CreateAdjustSpacesOperation(1, AdjustSpacesOption.ForceSpacesIfOnSingleLine);
                     case BinaryOperatorSpacingOptions.Remove:
-                        return CreateAdjustSpacesOperation(0, AdjustSpacesOption.ForceSpacesIfOnSingleLine);
+                        if (currentKind == SyntaxKind.IsKeyword ||
+                            currentKind == SyntaxKind.AsKeyword ||
+                            previousKind == SyntaxKind.IsKeyword ||
+                            previousKind == SyntaxKind.AsKeyword)
+                        {
+                            // User want spaces removed but at least one is required for the "as" & "is" keyword
+                            return CreateAdjustSpacesOperation(1, AdjustSpacesOption.ForceSpacesIfOnSingleLine);
+                        }
+                        else
+                        {
+                            return CreateAdjustSpacesOperation(0, AdjustSpacesOption.ForceSpacesIfOnSingleLine);
+                        }
                     case BinaryOperatorSpacingOptions.Ignore:
                         return CreateAdjustSpacesOperation(0, AdjustSpacesOption.PreserveSpaces);
                     default:

src/Workspaces/CSharpTest/Formatting/FormattingTests.cs

@@ -988,6 +988,34 @@ class D
 }", false, changingOptions);
         }
 
+        [Fact, Trait(Traits.Feature, Traits.Features.Formatting)]
+        public void RemoveSpacingAroundBinaryOperatorsShouldMakeAtLeastOneSpaceForIsAndAsKeywords()
+        {
+            var changingOptions = new Dictionary<OptionKey, object>();
+            changingOptions.Add(CSharpFormattingOptions.SpacingAroundBinaryOperator, BinaryOperatorSpacingOptions.Remove);
+            AssertFormat(@"class Class2
+{
+    public void nothing()
+    {
+        var a = 1*2+3-4/5;
+        a+=1;
+        object o = null;
+        string s = o as string;
+        bool b = o is string;
+    }
+}", @"class Class2
+    {
+    public void nothing()
+        {
+            var a = 1   *   2  +   3   -  4  /  5;
+            a    += 1;
+            object o = null;
+            string s = o        as       string;
+            bool b   = o        is       string;
+        }
+    }",  false, changingOptions);
+        }
+
         [WorkItem(772298, "DevDiv")]
         [Fact, Trait(Traits.Feature, Traits.Features.Formatting)]
         public void IndentUserSettingNonDefaultTest_OpenBracesOfLambdaWithNoNewLine()