SLVS-1600 Move html encoding inside DiffTranslator to have more contr…

…ol on the received html content and for better testability (e.g. html encoding and XML writer encoding sometimes lead to invalid characters, when XmlWriter encodes special characters from html escape characters)

src/Education.UnitTests/XamlGenerator/RuleHelpXamlTranslatorTests.cs

@@ -354,9 +354,7 @@ same 1</Paragraph>
         [TestMethod]
         public void TranslateHtmlToXaml_DataDiffWithAngleBracket_XMLParsable()
         {
-            var diffTranslator = new Mock<IDiffTranslator>();
-
-            IRuleHelpXamlTranslator testSubject = CreateTestSubject(diffTranslator: diffTranslator.Object);
+            IRuleHelpXamlTranslator testSubject = CreateTestSubject();
 
             var compliantText = "#include &lt;vector&gt;";
             var nonCompliantText = "#include &lt;vector&gt;";
@@ -365,8 +363,6 @@ public void TranslateHtmlToXaml_DataDiffWithAngleBracket_XMLParsable()
 
             var noncompliantXaml = @"#include &lt;vector&gt;";
 
-            diffTranslator.Setup(d => d.GetDiffXaml(compliantText, nonCompliantText)).Returns((noncompliantXaml, compliantXaml));
-
             var htmlText = $"<pre data-diff-type=\"compliant\" data-diff-id=\"1\">{compliantText}</pre>\n<pre data-diff-type =\"noncompliant\" data-diff-id=\"1\">{nonCompliantText}</pre>";
 
             var expectedText = @"<Section xml:space=""preserve"" Style=""{DynamicResource Pre_Section}"">
@@ -386,7 +382,7 @@ public void TranslateHtmlToXaml_SingleQuotesPresentInDiffCode_AreEscapedCorrectl
 
             var htmlText = @"
 <pre data-diff-id=""1"" data-diff-type=""noncompliant"">
-    function f(a, g){} // Noncompliant: 'f' returns 'b' on two different return statements
+function f(a, g){} // Noncompliant: 'f' returns 'b' on two different return statements
 </pre>
 <pre data-diff-id=""1"" data-diff-type=""compliant"">
 function f(a, g){}

src/Education/XamlGenerator/DiffTranslator.cs

@@ -20,6 +20,7 @@
 
 using System.ComponentModel.Composition;
 using System.Text;
+using System.Web;
 using System.Xml;
 using DiffPlex.DiffBuilder;
 using DiffPlex.DiffBuilder.Model;
@@ -51,7 +52,9 @@ public DiffTranslator(IXamlWriterFactory xamlWriterFactory)
 
         public (string noncompliantXaml, string compliantXaml) GetDiffXaml(string noncompliantHtml, string compliantHtml)
         {
-            var resultDiff = SideBySideDiffBuilder.Diff(oldText: noncompliantHtml, newText: compliantHtml, ignoreWhiteSpace: false);
+            var encodedNonCompliantHtml = HttpUtility.HtmlEncode(noncompliantHtml);
+            var encodedCompliantHtml = HttpUtility.HtmlEncode(compliantHtml);
+            var resultDiff = SideBySideDiffBuilder.Diff(oldText: encodedNonCompliantHtml, newText: encodedCompliantHtml, ignoreWhiteSpace: false);
 
             var highlightedNonCompliant = HighlightLines(resultDiff.OldText.Lines, StyleResourceNames.NonCompliant_Diff, StyleResourceNames.Sub_NonCompliant_Diff);
             var highlightedCompliant = HighlightLines(resultDiff.NewText.Lines, StyleResourceNames.Compliant_Diff, StyleResourceNames.Sub_Compliant_Diff);

src/Education/XamlGenerator/RuleHelpXamlTranslator.cs

@@ -601,7 +601,7 @@ private void ReplaceDiffs(StringBuilder sb)
                         continue;
                     }
 
-                    var diffXaml = diffTranslator.GetDiffXaml(HttpUtility.HtmlEncode(diffCodes[noncompliantKey]), HttpUtility.HtmlEncode(diffCodes[compliantKey]));
+                    var diffXaml = diffTranslator.GetDiffXaml(diffCodes[noncompliantKey], diffCodes[compliantKey]);
 
                     sb.Replace(noncompliantKey, diffXaml.noncompliantXaml);
                     sb.Replace(compliantKey, diffXaml.compliantXaml);