fix: Do not modify input options in the tokenize method

These options can be reused for parse, tokenize or validator methods. Calling tokenize flips the output from the parsed object to token arraym, which would break the following usage of the same options.

Author: prantlf

.vscode/settings.json

@@ -9,6 +9,7 @@
   "search.exclude": {
     "**/benchmarks": true,
     "**/coverage": true,
+    "**/lib/jsonlint.js": true,
     "**/test/fails": true,
     "**/test/passes": true,
     "**/test/recursive": true,

src/custom-parser.js

@@ -651,6 +651,11 @@ function tokenize (input, options) { // eslint-disable-line no-unused-vars
   if (!options) {
     options = {}
   }
+  // As long as this is the single modification, this is easier than cloning.
+  // (Once Node.js 6 is dropped, this can be replaced by object destructuring.)
+  var oldTokenize = options.tokenize
   options.tokenize = true
-  return parseInternal(input, options)
+  var tokens = parseInternal(input, options)
+  options.tokenize = oldTokenize
+  return tokens
 }

test/tokenize.js

@@ -127,4 +127,10 @@ addTest('without raw input, location and path properties', function () {
   })
 })
 
+addTest('does not enforce tokenization in the input options', function () {
+  var options = {}
+  tokenize('{}', options)
+  assert.equal(options.tokenize, undefined)
+})
+
 if (require.main === module) { require('test').run(exports) }