Parse the whitespace surrounding equals in attribute correctly

Author: ajaybhargavb

src/Microsoft.AspNet.Razor/Parser/HtmlMarkupParser.Block.cs

@@ -453,6 +453,7 @@ private void BeforeAttribute()
             // http://dev.w3.org/html5/spec/tokenization.html#attribute-name-state
             // Read the 'name' (i.e. read until the '=' or whitespace/newline)
             var name = Enumerable.Empty<HtmlSymbol>();
+            var whitespaceAfterAttributeName = Enumerable.Empty<HtmlSymbol>();
             if (At(HtmlSymbolType.Text))
             {
                 name = ReadWhile(sym =>
@@ -462,6 +463,11 @@ private void BeforeAttribute()
                                  sym.Type != HtmlSymbolType.CloseAngle &&
                                  sym.Type != HtmlSymbolType.OpenAngle &&
                                  (sym.Type != HtmlSymbolType.ForwardSlash || !NextIs(HtmlSymbolType.CloseAngle)));
+
+                // capture whitespace after attribute name (if any)
+                whitespaceAfterAttributeName = ReadWhile(
+                    sym => sym.Type == HtmlSymbolType.WhiteSpace ||
+                    sym.Type == HtmlSymbolType.NewLine);
             }
             else
             {
@@ -484,6 +490,7 @@ private void BeforeAttribute()
                 {
                     Accept(whitespace);
                     Accept(name);
+                    Accept(whitespaceAfterAttributeName);
                     Output(SpanKind.Markup);
                 }
 
@@ -497,11 +504,14 @@ private void BeforeAttribute()
             // Start a new markup block for the attribute
             using (Context.StartBlock(BlockType.Markup))
             {
-                AttributePrefix(whitespace, name);
+                AttributePrefix(whitespace, name, whitespaceAfterAttributeName);
             }
         }
 
-        private void AttributePrefix(IEnumerable<HtmlSymbol> whitespace, IEnumerable<HtmlSymbol> nameSymbols)
+        private void AttributePrefix(
+            IEnumerable<HtmlSymbol> whitespace,
+            IEnumerable<HtmlSymbol> nameSymbols,
+            IEnumerable<HtmlSymbol> whitespaceAfterAttributeName)
         {
             // First, determine if this is a 'data-' attribute (since those can't use conditional attributes)
             var name = nameSymbols.GetContent(Span.Start);
@@ -510,8 +520,13 @@ private void AttributePrefix(IEnumerable<HtmlSymbol> whitespace, IEnumerable<Htm
             // Accept the whitespace and name
             Accept(whitespace);
             Accept(nameSymbols);
+            Accept(whitespaceAfterAttributeName);
             Assert(HtmlSymbolType.Equals); // We should be at "="
             AcceptAndMoveNext();
+
+            // Accept the whitespace after Equals
+            AcceptWhile(sym => sym.Type == HtmlSymbolType.WhiteSpace || sym.Type == HtmlSymbolType.NewLine);
+
             var quote = HtmlSymbolType.Unknown;
             if (At(HtmlSymbolType.SingleQuote) || At(HtmlSymbolType.DoubleQuote))
             {

test/Microsoft.AspNet.Razor.Test/Parser/Html/HtmlAttributeTest.cs

@@ -28,6 +28,20 @@ public void SimpleLiteralAttribute()
                         Factory.Markup(" />").Accepts(AcceptedCharacters.None))));
         }
 
+        [Fact]
+        public void SimpleLiteralAttributeWithWhitespaceSurroundingEquals()
+        {
+            ParseBlockTest($"<a href {Environment.NewLine}= {Environment.NewLine}'Foo' />",
+                new MarkupBlock(
+                    new MarkupTagBlock(
+                        Factory.Markup("<a"),
+                        new MarkupBlock(new AttributeBlockChunkGenerator(name: "href", prefix: new LocationTagged<string>($" href {Environment.NewLine}= {Environment.NewLine}'", 2, 0, 2), suffix: new LocationTagged<string>("'", 18, 2, 4)),
+                            Factory.Markup($" href {Environment.NewLine}= {Environment.NewLine}'").With(SpanChunkGenerator.Null),
+                            Factory.Markup("Foo").With(new LiteralAttributeChunkGenerator(prefix: new LocationTagged<string>(string.Empty, 15, 2, 1), value: new LocationTagged<string>("Foo", 15, 2, 1))),
+                            Factory.Markup("'").With(SpanChunkGenerator.Null)),
+                        Factory.Markup(" />").Accepts(AcceptedCharacters.None))));
+        }
+
         [Fact]
         public void MultiPartLiteralAttribute()
         {