immutable string

README.md

@@ -163,6 +163,7 @@ Usage: `jsonlint [options] [--] [<file, directory, pattern> ...]`
     --enforce-single-quotes      surrounds all strings with single quotes
     --trim-trailing-commas       omit trailing commas from objects and arrays
     --succeed-with-no-files      succeed (exit code 0) if no files were found
+    --immutable-string           use immutable strings in parsing
     -v, --version                output the version number
     -h, --help                   display help for command
 

lib/cli.js

@@ -60,6 +60,7 @@ Options:
   --enforce-single-quotes      surrounds all strings with single quotes
   --trim-trailing-commas       omit trailing commas from objects and arrays
   --succeed-with-no-files      succeed (exit code 0) if no files were found
+  --immutable-string           use immutable strings in parsing
   -v, --version                output the version number
   -h, --help                   display help for command
 
@@ -220,6 +221,9 @@ for (let i = 2, l = argv.length; i < l; ++i) {
         case 'succeed-with-no-files':
           params.succeedWithNoFiles = flag
           return
+        case 'immutable-string':
+          params.immutableString = flag;
+          return;
         case 'v': case 'version':
           console.log(require('../package.json').version)
           process.exit(0)

src/custom-parser.js

@@ -57,6 +57,7 @@ function parseInternal (input, options) {
   const rawTokens = options.rawTokens
   const tokenLocations = options.tokenLocations
   const tokenPaths = options.tokenPaths
+  const immutableString = options.immutableString
 
   const isLineTerminator = json5 ? Uni.isLineTerminator : Uni.isLineTerminatorJSON
   const isWhiteSpace = json5 ? Uni.isWhiteSpace : Uni.isWhiteSpaceJSON
@@ -573,10 +574,14 @@ function parseInternal (input, options) {
   function parseString (endChar) {
     // 7.8.4 of ES262 spec
     let result = ''
+    const startPosition = position
     while (position < inputLength) {
       let char = input[position++]
       if (char === endChar) {
-        return result
+        if (immutableString)
+          return input.substr(startPosition, position - 1)
+        else
+          return result
       }if (char === '\\') {
         if (position >= inputLength) {
           fail()