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Co-authored-by: Sukka <isukkaw@gmail.com>
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Original file line number | Diff line number | Diff line change |
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'use strict'; | ||
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const through2 = require('through2'); | ||
const Parser = require('jsonparse'); | ||
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/** | ||
* Check whether a x and y are equal, or x matches y, or x(y) is truthy. | ||
* @param {boolean | string | RegExp | (args: any[]) => boolean} x | ||
* @param {*} y | ||
* @returns {boolean} | ||
*/ | ||
const check = (x, y) => { | ||
if (typeof x === 'string') { | ||
return y === x; | ||
} | ||
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if (x && typeof x.exec === 'function') { | ||
return x.exec(y); | ||
} | ||
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if (typeof x === 'boolean' || typeof x === 'object') { | ||
return x; | ||
} | ||
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if (typeof x === 'function') { | ||
return x(y); | ||
} | ||
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return false; | ||
}; | ||
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module.exports.parse = function(path, map) { | ||
let header, footer; | ||
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const parser = new Parser(); | ||
const stream = through2.obj( | ||
(chunk, enc, cb) => { | ||
if (typeof chunk === 'string') { | ||
chunk = Buffer.from(chunk); | ||
} | ||
parser.write(chunk); | ||
cb(); | ||
}, | ||
cb => { | ||
if (header) { | ||
stream.emit('header', header); | ||
} | ||
if (footer) { | ||
stream.emit('footer', footer); | ||
} | ||
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if (parser.tState !== Parser.C.START || parser.stack.length > 0) { | ||
cb(new Error('Incomplete JSON')); | ||
return; | ||
} | ||
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cb(); | ||
} | ||
); | ||
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if (typeof path === 'string') { | ||
path = path.split('.').map(e => { | ||
if (e === '$*') { | ||
return { emitKey: true }; | ||
} | ||
if (e === '*') { | ||
return true; | ||
} | ||
if (e === '') { | ||
// '..'.split('.') returns an empty string | ||
return { recurse: true }; | ||
} | ||
return e; | ||
}); | ||
} | ||
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if (!path || !path.length) { | ||
path = null; | ||
} | ||
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parser.onValue = function(value) { | ||
if (!this.root) { stream.root = value; } | ||
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if (!path) return; | ||
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let i = 0; // iterates on path | ||
let j = 0; // iterates on stack | ||
let emitKey = false; | ||
let emitPath = false; | ||
while (i < path.length) { | ||
const key = path[i]; | ||
let c; | ||
j++; | ||
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if (key && !key.recurse) { | ||
c = j === this.stack.length ? this : this.stack[j]; | ||
if (!c) return; | ||
if (!check(key, c.key)) { | ||
setHeaderFooter(c.key, value); | ||
return; | ||
} | ||
emitKey = !!key.emitKey; | ||
emitPath = !!key.emitPath; | ||
i++; | ||
} else { | ||
i++; | ||
const nextKey = path[i]; | ||
if (!nextKey) return; | ||
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// eslint-disable-next-line no-constant-condition | ||
while (true) { | ||
c = j === this.stack.length ? this : this.stack[j]; | ||
if (!c) return; | ||
if (check(nextKey, c.key)) { | ||
i++; | ||
if (!Object.isFrozen(this.stack[j])) { | ||
this.stack[j].value = null; | ||
} | ||
break; | ||
} else { | ||
setHeaderFooter(c.key, value); | ||
} | ||
j++; | ||
} | ||
} | ||
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} | ||
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// emit header | ||
if (header) { | ||
stream.emit('header', header); | ||
header = false; | ||
} | ||
if (j !== this.stack.length) return; | ||
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const actualPath = this.stack.slice(1).map(element => element.key); | ||
actualPath.push(this.key); | ||
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let data = this.value[this.key]; | ||
if (data != null) { | ||
if ((data = map ? map(data, actualPath) : data) != null) { | ||
if (emitKey || emitPath) { | ||
data = { | ||
value: data | ||
}; | ||
if (emitKey) { | ||
data.key = this.key; | ||
} | ||
if (emitPath) { | ||
data.path = actualPath; | ||
} | ||
} | ||
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stream.push(data); | ||
} | ||
} | ||
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delete this.value[this.key]; | ||
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for (const k in this.stack) { | ||
if (!Object.isFrozen(this.stack[k])) { | ||
this.stack[k].value = null; | ||
} | ||
} | ||
}; | ||
parser._onToken = parser.onToken; | ||
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parser.onToken = function(token, value) { | ||
parser._onToken(token, value); | ||
if (this.stack.length === 0) { | ||
if (stream.root) { | ||
if (!path) { stream.push(stream.root); } | ||
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stream.root = null; | ||
} | ||
} | ||
}; | ||
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parser.onError = function(err) { | ||
if (err.message.includes('at position')) { | ||
err.message = 'Invalid JSON (' + err.message + ')'; | ||
} | ||
stream.destroy(err); | ||
}; | ||
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return stream; | ||
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function setHeaderFooter(key, value) { | ||
// header has not been emitted yet | ||
if (header !== false) { | ||
header = header || {}; | ||
header[key] = value; | ||
} | ||
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// footer has not been emitted yet but header has | ||
if (footer !== false && header === false) { | ||
footer = footer || {}; | ||
footer[key] = value; | ||
} | ||
} | ||
}; |
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