Simplify condition checks

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers/LayoutRules/SA1516ElementsMustBeSeparatedByBlankLine.cs

@@ -345,19 +345,25 @@ private static void HandleMemberList(SyntaxNodeAnalysisContext context, SyntaxLi
 
                 if (!members[i - 1].ContainsDiagnostics && !members[i].ContainsDiagnostics)
                 {
-                    // Don't report if
-                    // the previous declaration is of the same type
-                    // AND it is either
-                    // - a single line field declaration where the previous field is single line
-                    // or
-                    // - a single line property declaration where the previous property is single line
-                    if (members[i - 1].IsKind(members[i].Kind())
-                        && ((members[i].IsKind(SyntaxKind.FieldDeclaration)
-                             && !IsMultiline((FieldDeclarationSyntax)members[i])
-                             && !IsMultiline((FieldDeclarationSyntax)members[i - 1]))
-                            || (members[i].IsKind(SyntaxKind.PropertyDeclaration)
-                                && !IsMultiline((PropertyDeclarationSyntax)members[i])
-                                && !IsMultiline((PropertyDeclarationSyntax)members[i - 1]))))
+                    // Report if
+                    // the current declaration is not a field declaration or property declaration
+                    // or the previous declaration is of different type
+                    // or the previous declaration spans across multiple lines
+                    //
+                    // Note that the order of checking is important, as the call to IsMultiLine requires a
+                    // FieldDeclarationSyntax or PropertyDeclarationSyntax, something that can only be guaranteed if the
+                    // first two checks fail.
+                    if (members[i].IsKind(SyntaxKind.FieldDeclaration)
+                        && members[i - 1].IsKind(members[i].Kind())
+                        && !IsMultiline((FieldDeclarationSyntax)members[i - 1]))
+                    {
+                        continue;
+                    }
+
+                    if (members[i].IsKind(SyntaxKind.PropertyDeclaration)
+                        && members[i - 1].IsKind(members[i].Kind())
+                        && !IsMultiline((PropertyDeclarationSyntax)members[i])
+                        && !IsMultiline((PropertyDeclarationSyntax)members[i - 1]))
                     {
                         continue;
                     }