kaguranana-birthday-project/node_modules/json-parse-even-better-errors/index.js
2021-12-12 18:49:32 -08:00

122 lines
3.8 KiB
JavaScript

'use strict'
const hexify = char => {
const h = char.charCodeAt(0).toString(16).toUpperCase()
return '0x' + (h.length % 2 ? '0' : '') + h
}
const parseError = (e, txt, context) => {
if (!txt) {
return {
message: e.message + ' while parsing empty string',
position: 0,
}
}
const badToken = e.message.match(/^Unexpected token (.) .*position\s+(\d+)/i)
const errIdx = badToken ? +badToken[2]
: e.message.match(/^Unexpected end of JSON.*/i) ? txt.length - 1
: null
const msg = badToken ? e.message.replace(/^Unexpected token ./, `Unexpected token ${
JSON.stringify(badToken[1])
} (${hexify(badToken[1])})`)
: e.message
if (errIdx !== null && errIdx !== undefined) {
const start = errIdx <= context ? 0
: errIdx - context
const end = errIdx + context >= txt.length ? txt.length
: errIdx + context
const slice = (start === 0 ? '' : '...') +
txt.slice(start, end) +
(end === txt.length ? '' : '...')
const near = txt === slice ? '' : 'near '
return {
message: msg + ` while parsing ${near}${JSON.stringify(slice)}`,
position: errIdx,
}
} else {
return {
message: msg + ` while parsing '${txt.slice(0, context * 2)}'`,
position: 0,
}
}
}
class JSONParseError extends SyntaxError {
constructor (er, txt, context, caller) {
context = context || 20
const metadata = parseError(er, txt, context)
super(metadata.message)
Object.assign(this, metadata)
this.code = 'EJSONPARSE'
this.systemError = er
Error.captureStackTrace(this, caller || this.constructor)
}
get name () { return this.constructor.name }
set name (n) {}
get [Symbol.toStringTag] () { return this.constructor.name }
}
const kIndent = Symbol.for('indent')
const kNewline = Symbol.for('newline')
// only respect indentation if we got a line break, otherwise squash it
// things other than objects and arrays aren't indented, so ignore those
// Important: in both of these regexps, the $1 capture group is the newline
// or undefined, and the $2 capture group is the indent, or undefined.
const formatRE = /^\s*[{\[]((?:\r?\n)+)([\s\t]*)/
const emptyRE = /^(?:\{\}|\[\])((?:\r?\n)+)?$/
const parseJson = (txt, reviver, context) => {
const parseText = stripBOM(txt)
context = context || 20
try {
// get the indentation so that we can save it back nicely
// if the file starts with {" then we have an indent of '', ie, none
// otherwise, pick the indentation of the next line after the first \n
// If the pattern doesn't match, then it means no indentation.
// JSON.stringify ignores symbols, so this is reasonably safe.
// if the string is '{}' or '[]', then use the default 2-space indent.
const [, newline = '\n', indent = ' '] = parseText.match(emptyRE) ||
parseText.match(formatRE) ||
[, '', '']
const result = JSON.parse(parseText, reviver)
if (result && typeof result === 'object') {
result[kNewline] = newline
result[kIndent] = indent
}
return result
} catch (e) {
if (typeof txt !== 'string' && !Buffer.isBuffer(txt)) {
const isEmptyArray = Array.isArray(txt) && txt.length === 0
throw Object.assign(new TypeError(
`Cannot parse ${isEmptyArray ? 'an empty array' : String(txt)}`
), {
code: 'EJSONPARSE',
systemError: e,
})
}
throw new JSONParseError(e, parseText, context, parseJson)
}
}
// Remove byte order marker. This catches EF BB BF (the UTF-8 BOM)
// because the buffer-to-string conversion in `fs.readFileSync()`
// translates it to FEFF, the UTF-16 BOM.
const stripBOM = txt => String(txt).replace(/^\uFEFF/, '')
module.exports = parseJson
parseJson.JSONParseError = JSONParseError
parseJson.noExceptions = (txt, reviver) => {
try {
return JSON.parse(stripBOM(txt), reviver)
} catch (e) {}
}