Add "there and back again" test

ConsoleDemo/Program.cs

@@ -34,19 +34,14 @@ namespace ConsoleDemo
         private static void ProcessFile(string fileName)
         {
             var text = File.ReadAllText(fileName);
-            //Console.Write($"Parsing {fileName}...");
             var window = new TextWindowWithNull(text, fileName);
             var parser = CreateParser(window);
             var tree = parser.Parse();
-            //Console.WriteLine("Done.");
             var actual = tree.FullText;
             if (actual != text)
             {
                 throw new ApplicationException();
             }
-            //var printer = new PrettyPrinter();
-            //printer.Visit(tree);
-            //Console.ReadKey();
         }
 
         static Program()

Parser.Tests/ThereAndBackAgain.cs

@@ -0,0 +1,82 @@
+using System;
+using NUnit.Framework;
+using System.Collections.Generic;
+using System.IO;
+
+namespace Parser.Tests
+{
+    public class ThereAndBackAgain
+    {
+        static ThereAndBackAgain()
+        {
+            switch (Environment.OSVersion.Platform)
+            {
+                case PlatformID.MacOSX:
+                case PlatformID.Unix:
+                    BaseDirectory = BaseDirectoryMacOs;
+                    break;
+                default:
+                    BaseDirectory = BaseDirectoryWindows;
+                    break;
+            }
+        }
+
+        private static readonly string BaseDirectory;
+        private const string BaseDirectoryMacOs = @"/Applications/MATLAB_R2017b.app/toolbox/matlab/";
+        private const string BaseDirectoryWindows = @"D:\Program Files\MATLAB\R2018a\toolbox\matlab\";
+
+        private static readonly HashSet<string> SkipFiles = new HashSet<string>
+        {
+            @"codetools\private\template.m", // this is a template, so it contains '$' characters.
+            @"plottools\+matlab\+graphics\+internal\+propertyinspector\+views\CategoricalHistogramPropertyView.m", // this one contains a 0xA0 character (probably it's 'non-breakable space' in Win-1252).
+            @"plottools\+matlab\+graphics\+internal\+propertyinspector\+views\PrimitiveHistogram2PropertyView.m", // same
+            @"plottools\+matlab\+graphics\+internal\+propertyinspector\+views\PrimitiveHistogramPropertyView.m", // same
+            @"codetools/private/template.m", // this is a template, so it contains '$' characters.
+            @"plottools/+matlab/+graphics/+internal/+propertyinspector/+views/CategoricalHistogramPropertyView.m", // this one contains a 0xA0 character (probably it's 'non-breakable space' in Win-1252).
+            @"plottools/+matlab/+graphics/+internal/+propertyinspector/+views/PrimitiveHistogram2PropertyView.m", // same
+            @"plottools/+matlab/+graphics/+internal/+propertyinspector/+views/PrimitiveHistogramPropertyView.m", // same
+        };
+
+        private static MParser CreateParser(ITextWindow window)
+        {
+            return new MParser(window);
+        }
+
+        private static void ProcessFile(string fileName)
+        {
+            var text = File.ReadAllText(fileName);
+            var window = new TextWindowWithNull(text, fileName);
+            var parser = CreateParser(window);
+            var tree = parser.Parse();
+            var actual = tree.FullText;
+            Assert.That(actual == text);
+        }
+
+        private static void ProcessDirectory(string directory)
+        {
+            var files = Directory.GetFiles(directory, "*.m");
+            foreach (var file in files)
+            {
+                var relativePath = Path.GetRelativePath(BaseDirectory, file);
+                if (SkipFiles.Contains(relativePath))
+                {
+                    continue;
+                }
+                ProcessFile(file);
+            }
+
+            var subDirectories = Directory.GetDirectories(directory);
+            foreach (var subDirectory in subDirectories)
+            {
+                ProcessDirectory(subDirectory);
+            }
+        }
+
+        [Category("Slow")]
+        [Test]
+        public void TestEverything()
+        {
+            ProcessDirectory(BaseDirectory);
+        }
+    }
+}

Parser/Internal/MParserGreen.cs

@@ -143,7 +143,7 @@ namespace Parser.Internal
             }
             else
             {
-                throw new ParsingException($"Unexpected token {CurrentToken} during parsing function output descritpion at {CurrentPosition}.");
+                throw new ParsingException($"Unexpected token {CurrentToken} during parsing function output description at {CurrentPosition}.");
             }
 
             return Factory.FunctionOutputDescriptionSyntax(builder.ToList(), assignmentSign);