source: trip-planner-front/node_modules/json-parse-even-better-errors/index.js@ e29cc2e

Last change on this file since e29cc2e was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

initial commit

  • Property mode set to 100644
File size: 3.8 KB
Line 
1'use strict'
2
3const hexify = char => {
4 const h = char.charCodeAt(0).toString(16).toUpperCase()
5 return '0x' + (h.length % 2 ? '0' : '') + h
6}
7
8const parseError = (e, txt, context) => {
9 if (!txt) {
10 return {
11 message: e.message + ' while parsing empty string',
12 position: 0,
13 }
14 }
15 const badToken = e.message.match(/^Unexpected token (.) .*position\s+(\d+)/i)
16 const errIdx = badToken ? +badToken[2]
17 : e.message.match(/^Unexpected end of JSON.*/i) ? txt.length - 1
18 : null
19
20 const msg = badToken ? e.message.replace(/^Unexpected token ./, `Unexpected token ${
21 JSON.stringify(badToken[1])
22 } (${hexify(badToken[1])})`)
23 : e.message
24
25 if (errIdx !== null && errIdx !== undefined) {
26 const start = errIdx <= context ? 0
27 : errIdx - context
28
29 const end = errIdx + context >= txt.length ? txt.length
30 : errIdx + context
31
32 const slice = (start === 0 ? '' : '...') +
33 txt.slice(start, end) +
34 (end === txt.length ? '' : '...')
35
36 const near = txt === slice ? '' : 'near '
37
38 return {
39 message: msg + ` while parsing ${near}${JSON.stringify(slice)}`,
40 position: errIdx,
41 }
42 } else {
43 return {
44 message: msg + ` while parsing '${txt.slice(0, context * 2)}'`,
45 position: 0,
46 }
47 }
48}
49
50class JSONParseError extends SyntaxError {
51 constructor (er, txt, context, caller) {
52 context = context || 20
53 const metadata = parseError(er, txt, context)
54 super(metadata.message)
55 Object.assign(this, metadata)
56 this.code = 'EJSONPARSE'
57 this.systemError = er
58 Error.captureStackTrace(this, caller || this.constructor)
59 }
60 get name () { return this.constructor.name }
61 set name (n) {}
62 get [Symbol.toStringTag] () { return this.constructor.name }
63}
64
65const kIndent = Symbol.for('indent')
66const kNewline = Symbol.for('newline')
67// only respect indentation if we got a line break, otherwise squash it
68// things other than objects and arrays aren't indented, so ignore those
69// Important: in both of these regexps, the $1 capture group is the newline
70// or undefined, and the $2 capture group is the indent, or undefined.
71const formatRE = /^\s*[{\[]((?:\r?\n)+)([\s\t]*)/
72const emptyRE = /^(?:\{\}|\[\])((?:\r?\n)+)?$/
73
74const parseJson = (txt, reviver, context) => {
75 const parseText = stripBOM(txt)
76 context = context || 20
77 try {
78 // get the indentation so that we can save it back nicely
79 // if the file starts with {" then we have an indent of '', ie, none
80 // otherwise, pick the indentation of the next line after the first \n
81 // If the pattern doesn't match, then it means no indentation.
82 // JSON.stringify ignores symbols, so this is reasonably safe.
83 // if the string is '{}' or '[]', then use the default 2-space indent.
84 const [, newline = '\n', indent = ' '] = parseText.match(emptyRE) ||
85 parseText.match(formatRE) ||
86 [, '', '']
87
88 const result = JSON.parse(parseText, reviver)
89 if (result && typeof result === 'object') {
90 result[kNewline] = newline
91 result[kIndent] = indent
92 }
93 return result
94 } catch (e) {
95 if (typeof txt !== 'string' && !Buffer.isBuffer(txt)) {
96 const isEmptyArray = Array.isArray(txt) && txt.length === 0
97 throw Object.assign(new TypeError(
98 `Cannot parse ${isEmptyArray ? 'an empty array' : String(txt)}`
99 ), {
100 code: 'EJSONPARSE',
101 systemError: e,
102 })
103 }
104
105 throw new JSONParseError(e, parseText, context, parseJson)
106 }
107}
108
109// Remove byte order marker. This catches EF BB BF (the UTF-8 BOM)
110// because the buffer-to-string conversion in `fs.readFileSync()`
111// translates it to FEFF, the UTF-16 BOM.
112const stripBOM = txt => String(txt).replace(/^\uFEFF/, '')
113
114module.exports = parseJson
115parseJson.JSONParseError = JSONParseError
116
117parseJson.noExceptions = (txt, reviver) => {
118 try {
119 return JSON.parse(stripBOM(txt), reviver)
120 } catch (e) {}
121}
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