Paul Lewis | 911c1b8 | 2019-12-02 12:46:15 +0000 | [diff] [blame] | 1 | 'use strict' |
| 2 | |
| 3 | module.exports = parseJson |
| 4 | function parseJson (txt, reviver, context) { |
| 5 | context = context || 20 |
| 6 | try { |
| 7 | return JSON.parse(txt, reviver) |
| 8 | } catch (e) { |
| 9 | if (typeof txt !== 'string') { |
| 10 | const isEmptyArray = Array.isArray(txt) && txt.length === 0 |
| 11 | const errorMessage = 'Cannot parse ' + |
| 12 | (isEmptyArray ? 'an empty array' : String(txt)) |
| 13 | throw new TypeError(errorMessage) |
| 14 | } |
| 15 | const syntaxErr = e.message.match(/^Unexpected token.*position\s+(\d+)/i) |
| 16 | const errIdx = syntaxErr |
| 17 | ? +syntaxErr[1] |
| 18 | : e.message.match(/^Unexpected end of JSON.*/i) |
| 19 | ? txt.length - 1 |
| 20 | : null |
| 21 | if (errIdx != null) { |
| 22 | const start = errIdx <= context |
| 23 | ? 0 |
| 24 | : errIdx - context |
| 25 | const end = errIdx + context >= txt.length |
| 26 | ? txt.length |
| 27 | : errIdx + context |
| 28 | e.message += ` while parsing near '${ |
| 29 | start === 0 ? '' : '...' |
| 30 | }${txt.slice(start, end)}${ |
| 31 | end === txt.length ? '' : '...' |
| 32 | }'` |
| 33 | } else { |
| 34 | e.message += ` while parsing '${txt.slice(0, context * 2)}'` |
| 35 | } |
| 36 | throw e |
| 37 | } |
| 38 | } |