wishthis/node_modules/append-buffer/index.js

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2022-01-21 08:28:41 +00:00
'use strict';
var os = require('os');
var equals = require('buffer-equal');
var cr = new Buffer('\r\n');
var nl = new Buffer('\n');
/**
* Append a buffer to another buffer ensuring to preserve line ending characters.
*
* ```js
* console.log([appendBuffer(new Buffer('abc\r\n'), new Buffer('def')).toString()]);
* //=> [ 'abc\r\ndef\r\n' ]
*
* console.log([appendBuffer(new Buffer('abc\n'), new Buffer('def')).toString()]);
* //=> [ 'abc\ndef\n' ]
*
* // uses os.EOL when a line ending is not found
* console.log([appendBuffer(new Buffer('abc'), new Buffer('def')).toString()]);
* //=> [ 'abc\ndef' ]
* * ```
* @param {Buffer} `buf` Buffer that will be used to check for an existing line ending. The suffix is appended to this.
* @param {Buffer} `suffix` Buffer that will be appended to the buf.
* @return {Buffer} Final Buffer
* @api public
*/
module.exports = function appendBuffer(buf, suffix) {
if (!suffix || !suffix.length) {
return buf;
}
var eol;
if (equals(buf.slice(-2), cr)) {
eol = cr;
} else if (equals(buf.slice(-1), nl)) {
eol = nl;
} else {
return Buffer.concat([buf, new Buffer(os.EOL), new Buffer(suffix)]);
}
return Buffer.concat([buf, new Buffer(suffix), eol]);
};