Fix #1385 (#1390)

* Fix #1385

Fix for issue #1385
Ignore whitespace inside the quote
Ignore quotes if seeking == Boundary.WordEnd
Handle edge cases

* Update CommandLineStringSplitter.cs

Optimizing string operations

Author: krsahab

src/System.CommandLine.Tests/Parsing/CommandLineStringSplitterTests.cs

@@ -75,5 +75,25 @@ public void It_handles_multiple_options_with_quoted_arguments()
                          destination,
                          "--verbose");
         }
+
+        [Fact]
+        public void Internal_quotes_do_not_cause_string_to_be_split()
+        {
+            var commandLine = @"POST --raw='{""Id"":1,""Name"":""Alice""}'";
+
+            _splitter.Split(commandLine)
+                     .Should()
+                     .BeEquivalentTo("POST", "--raw='{Id:1,Name:Alice}'");
+        }
+
+        [Fact]
+        public void Internal_whitespaces_are_preserved_and_do_not_cause_string_to_be_split()
+        {
+            var commandLine = @"command --raw='{""Id"":1,""Movie Name"":""The Three Musketeers""}'";
+
+            _splitter.Split(commandLine)
+                     .Should()
+                     .BeEquivalentTo("command", "--raw='{Id:1,Movie Name:The Three Musketeers}'");
+        }
     }
 }

src/System.CommandLine/Parsing/CommandLineStringSplitter.cs

@@ -13,6 +13,7 @@ private enum Boundary
         {
             TokenStart,
             WordEnd,
+            QuoteStart,
             QuoteEnd
         }
 
@@ -25,52 +26,63 @@ public IEnumerable<string> Split(string commandLine)
             var pos = 0;
 
             var seeking = Boundary.TokenStart;
-            int? skipQuoteAtIndex = null;
+            var seekingQuote = Boundary.QuoteStart;
 
             while (pos < memory.Length)
             {
                 var c = memory.Span[pos];
 
                 if (char.IsWhiteSpace(c))
                 {
-                    switch (seeking)
+                    if (seekingQuote == Boundary.QuoteStart)
                     {
-                        case Boundary.WordEnd:
-                            yield return CurrentToken();
-                            startTokenIndex = pos;
-                            seeking = Boundary.TokenStart;
-                            break;
-
-                        case Boundary.TokenStart:
-                            startTokenIndex = pos;
-                            break;
-
-                        case Boundary.QuoteEnd:
-                            break;
+                        switch (seeking)
+                        {
+                            case Boundary.WordEnd:
+                                yield return CurrentToken();
+                                startTokenIndex = pos;
+                                seeking = Boundary.TokenStart;
+                                break;
+
+                            case Boundary.TokenStart:
+                                startTokenIndex = pos;
+                                break;
+                        }
                     }
                 }
                 else if (c == '\"')
                 {
-                    switch (seeking)
+                    if (seeking == Boundary.TokenStart)
                     {
-                        case Boundary.QuoteEnd:
-                            yield return CurrentToken();
-                            startTokenIndex = pos;
-                            seeking = Boundary.TokenStart;
-                            break;
-
-                        case Boundary.TokenStart:
-                            startTokenIndex = pos + 1;
-                            seeking = Boundary.QuoteEnd;
-                            break;
-
-                        case Boundary.WordEnd:
-                            seeking = Boundary.QuoteEnd;
-                            skipQuoteAtIndex = pos;
-                            break;
+                        switch (seekingQuote)
+                        {
+                            case Boundary.QuoteEnd:
+                                yield return CurrentToken();
+                                startTokenIndex = pos;
+                                seekingQuote = Boundary.QuoteStart;
+                                break;
+
+                            case Boundary.QuoteStart:
+                                startTokenIndex = pos + 1;
+                                seekingQuote = Boundary.QuoteEnd;
+                                break;
+                        }
+                    }
+                    else
+                    {
+                        switch (seekingQuote)
+                        {
+                            case Boundary.QuoteEnd:
+                                seekingQuote = Boundary.QuoteStart;
+                                break;
+
+                            case Boundary.QuoteStart:
+                                seekingQuote = Boundary.QuoteEnd;
+                                break;
+                        }
                     }
                 }
-                else if (seeking == Boundary.TokenStart)
+                else if (seeking == Boundary.TokenStart && seekingQuote == Boundary.QuoteStart)
                 {
                     seeking = Boundary.WordEnd;
                     startTokenIndex = pos;
@@ -95,29 +107,7 @@ public IEnumerable<string> Split(string commandLine)
 
             string CurrentToken()
             {
-                if (skipQuoteAtIndex is null)
-                {
-                    return memory.Slice(
-                                     startTokenIndex,
-                                     IndexOfEndOfToken())
-                                 .ToString();
-                }
-                else
-                {
-                    var beforeQuote = memory.Slice(
-                        startTokenIndex,
-                        skipQuoteAtIndex.Value - startTokenIndex);
-
-                    var indexOfCharAfterQuote = skipQuoteAtIndex.Value + 1;
-
-                    var afterQuote = memory.Slice(
-                        indexOfCharAfterQuote,
-                        pos - skipQuoteAtIndex.Value - 1);
-
-                    skipQuoteAtIndex = null;
-
-                    return $"{beforeQuote}{afterQuote}";
-                }
+                return memory.Slice(startTokenIndex, IndexOfEndOfToken()).ToString().Replace("\"", "");
             }
 
             int IndexOfEndOfToken() => pos - startTokenIndex;