fix: Ensure, that tokens and keys in error messages are enclosed in quotation marks

Author: prantlf

README.md

@@ -45,7 +45,7 @@ Example of an error message:
     Parse error on line 1, column 14:
     {"creative": ?}
     -------------^
-    Unexpected token ?
+    Unexpected token "?"
 
 ## Command-line Interface
 
@@ -198,7 +198,7 @@ The following code logs twice the following message:
     Parse error on line 1, column 14:
     {"creative": ?}
     -------------^
-    Unexpected token ?
+    Unexpected token "?"
 
 ```js
 const { parse } = require('@prantlf/jsonlint')

src/custom-parser.js

@@ -61,13 +61,7 @@ function parseCustom (input, options) { // eslint-disable-line no-unused-vars
   function generateMessage () {
     var message
     if (position < inputLength) {
-      var token = '\'' +
-        JSON
-          .stringify(input[position])
-          .replace(/^"|"$/g, '')
-          .replace(/'/g, "\\'")
-          .replace(/\\"/g, '"') +
-        '\''
+      var token = JSON.stringify(input[position])
       message = 'Unexpected token ' + token
     } else {
       message = 'Unexpected end of input'
@@ -229,7 +223,7 @@ function parseCustom (input, options) { // eslint-disable-line no-unused-vars
       skipWhiteSpace()
       var key = parseKey()
       if (allowDuplicateObjectKeys === false && result[key]) {
-        fail('Duplicate key: ' + key)
+        fail('Duplicate key: "' + key + '"')
       }
       skipWhiteSpace()
 
@@ -246,10 +240,10 @@ function parseCustom (input, options) { // eslint-disable-line no-unused-vars
         var value = parseGeneric()
         stack.pop()
 
-        if (value === undefined) fail('No value found for key ' + key)
+        if (value === undefined) fail('No value found for key "' + key + '"')
         if (typeof key !== 'string') {
           if (!json5 || typeof key !== 'number') {
-            fail('Wrong key type: ' + key)
+            fail('Wrong key type: "' + key + '"')
           }
         }
 

test/parse3.js

@@ -11,7 +11,13 @@ function addTest (arg, row, col, errRegExp) {
     } catch (err) {
       if (row !== undefined) assert.equal(err.location.start.line, row, 'wrong row: ' + err.location.start.line)
       if (col !== undefined) assert.equal(err.location.start.column, col, 'wrong column: ' + err.location.start.column)
-      if (errRegExp) assert(errRegExp.exec(err.message))
+      try {
+        if (errRegExp) assert(errRegExp.exec(err.message))
+      } catch (error) {
+        console.log('Message:', err.message)
+        console.log('RegExp: ', errRegExp)
+        throw error
+      }
       return
     }
     throw Error('no error')
@@ -47,7 +53,7 @@ addTest('nulz', 1, 1)
 
 // no data
 addTest('  ', 1, 3, /No data.*whitespace/)
-addTest('blah', 1, 1, /Unexpected token 'b'/)
+addTest('blah', 1, 1, /Unexpected token "b"/)
 addTest('', 1, 1, /No data.*empty input/)
 
 try {