convert non-printable char to unicode point

Author: itn3000

Cs2Mermaid.Lib/ConvertCsToMermaid.cs

@@ -128,7 +128,19 @@ static void ConvertInternal(TextWriter tw, string currentNodeName, SyntaxNode no
             }
             else
             {
-                tw.WriteLine($"{indent}{currentNodeName} --> {childNodeName}[\"{child.Kind()} {child.ToString()}\"]");
+                var tokenString = child.ToString().Aggregate(new StringBuilder(), (sb, c) => 
+                {
+                    if(char.IsWhiteSpace(c) || c == '"' || char.IsControl(c))
+                    {
+                        sb.Append("\\u" + ((int)c).ToString("x04"));
+                    }
+                    else
+                    {
+                        sb.Append(c);
+                    }
+                    return sb;
+                }).ToString();
+                tw.WriteLine($"{indent}{currentNodeName} --> {childNodeName}[\"{child.Kind()} {tokenString}\"]");
             }
         }
         if (!hasChild)

Cs2Mermaid.Test/ConvertTest.cs

@@ -99,5 +99,6 @@ public void LangVersionTest()
         options.LangVersion = "CSharp10";
         var cs10_0 = ConvertCsToMermaid.Convert(code, options);
         _OutputHelper.WriteLine("cs10 = " + cs10_0);
+        Assert.NotEqual(cs10_0, cs7_3);
     }
 }

Cs2Mermaid.Test/TestClasses/DoubleQuote.cs

@@ -0,0 +1,7 @@
+class CDoubleQuote
+{
+    string x = "yyyyy";
+    string y = @"
+    abcde
+    ";
+}