New commit using TS scanner.

This commit uses TS scanner and replaces comments token text
by whitespaces to preserve orginal positions.

src/compiler/commandLineParser.ts

@@ -421,91 +421,49 @@ namespace ts {
      * This method replace comment content by whitespace rather than completely remove them to keep positions in json parsing error reporting accurate.
      */
     function removeComments(jsonText: string): string {
-        let result = "";
-        let processingString = false;
-        let processingSingleLineComment = false;
-        let processingMultiLineComment = false;
-        for (let i = 0; i < jsonText.length; i++) {
-            let currentCharCode = jsonText.charCodeAt(i);
-            let currentChar = jsonText.charAt(i);
-            let nextCharCode = (i + 1 < jsonText.length) ? jsonText.charCodeAt(i + 1) : undefined;
-            if (processingString) {
-                if (currentCharCode === CharacterCodes.backslash
-                    && nextCharCode !== undefined) {
-                    // Found an escaped character 
-                    // consume the \ and the escaped char
-                    result += currentChar;
-                    result += jsonText.charAt(i + 1);
-                    i += 1;
-                }
-                else if (currentCharCode === CharacterCodes.doubleQuote) {
-                    // End of string
-                    result += currentChar;
-                    processingString = false;
-                }
-                else {
-                   // String content
-                   result += currentChar;
-                }
-            }
-            else if (processingSingleLineComment) {
-                if (isLineBreak(currentCharCode)) {
-                    // End of single line comment
-                    processingSingleLineComment = false;
-                    // Keep the line breaks to keep line numbers aligned
-                    result += currentChar;
-                }
-                else {
-                   // replace comment content by whitespaces
-                   result += " ";
-                }
-            }
-            else if (processingMultiLineComment) {
-                if (currentCharCode === CharacterCodes.asterisk && nextCharCode === CharacterCodes.slash) {
-                    // End of comment */
-                    result += "  ";
-                    i += 1;
-                    processingMultiLineComment = false;
-                }
-                else if (isLineBreak(currentCharCode)) {
-                    // Keep the line breaks to Keep line aligned
-                    result += currentChar;
-                }
-                else {
-                   // replace comment content by whitespaces
-                   result += " ";
-                }
-            }
-            else if (currentCharCode === CharacterCodes.doubleQuote) {
-                // String start
-                result += currentChar;
-                processingString = true;
-            }
-            else if (currentCharCode === CharacterCodes.hash) {
-                // Start of # comment
-                result += " ";
-                processingSingleLineComment = true;
-            }
-            else if (currentCharCode === CharacterCodes.slash && nextCharCode === CharacterCodes.slash) {
-                // Start of // comment
-                result += "  ";
-                i += 1;
-                processingSingleLineComment = true;
-            }
-            else if (currentCharCode === CharacterCodes.slash && nextCharCode === CharacterCodes.asterisk) {
-                // Start of /**/ comment
-                result += "  ";
-                i += 1;
-                processingMultiLineComment = true;
-            }
-            else {
-                // Keep other characters
-                result += currentChar;
+        let output = "";
+        let scanner = createScanner(ScriptTarget.ES5, /* skipTrivia */ false, LanguageVariant.Standard, jsonText);
+        let token: SyntaxKind;
+        while ((token = scanner.scan()) !== SyntaxKind.EndOfFileToken) {
+            switch (token) {
+                case SyntaxKind.SingleLineCommentTrivia:
+                case SyntaxKind.MultiLineCommentTrivia:
+                    // replace comments with whitespaces to preserve original characters position
+                    output += replaceWithWhitespaces(scanner.getTokenText());
+                    break;
+                default:
+                    output += scanner.getTokenText();
+                    break;
             }
         }
-        return result;
+        return output;
+
+        function replaceWithWhitespaces(commentTokenText: string): string {
+            let result = "";
+            let pos = 0;
+            let start = 0;
+            while (pos < commentTokenText.length) {
+                if (isLineBreak(commentTokenText.charCodeAt(pos))) {
+                    let nbCharToReplace = pos - start;
+                    result += nSpaces(nbCharToReplace);
+                    result += commentTokenText.charAt(pos);
+                    pos += 1;
+                    start = pos;
+                }
+                else {
+                    pos += 1;
+                }
+            }
+            result += nSpaces(pos - start);
+            return result;
+
+            function nSpaces(n: number): string {
+                return new Array(n + 1).join(" ");
+            };
+        }
     }
 
+
     /**
       * Parse the contents of a config file (tsconfig.json).
       * @param json The contents of the config file to parse

tests/cases/unittests/tsconfigParsing.ts

@@ -21,7 +21,6 @@ module ts {
     
     it("returns empty config for file with comments only", () => {
       assertParseResult("// Comment", { config: {} });
-      assertParseResult("# Comment", { config: {} });
       assertParseResult("/* Comment*/", { config: {} });
     });
 
@@ -37,19 +36,12 @@ module ts {
   					"file.d.ts"
   				]
       	}`, { config: { exclude: ["file.d.ts"] } });
-      assertParseResult(
-        `{
-      		# Excluded files
-      		"exclude": [
-  					# Exclude d.ts
-  					"file.d.ts"
-  				]
-      	}`, { config: { exclude: ["file.d.ts"] } });
+    
       assertParseResult(
         `{
       		/* Excluded
-      			 Files
-      		*/
+             Files
+          */
       		"exclude": [  		
   					/* multiline comments can be in the middle of a line */"file.d.ts"
   				]
@@ -60,16 +52,10 @@ module ts {
       assertParseResult(
         `{
       		"exclude": [
-  					"xx//file.d.ts"
+            "xx//file.d.ts"
   				]
       	}`, { config: { exclude: ["xx//file.d.ts"] } });
-      assertParseResult(
-        `{
-      		"exclude": [
-  					"xx#file.d.ts"
-  				]
-      	}`, { config: { exclude: ["xx#file.d.ts"] } });
-      assertParseResult(
+     assertParseResult(
         `{
       		"exclude": [
   					"xx/*file.d.ts*/"