/**
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* stream.js: Transport for outputting to any arbitrary stream.
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*
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* (C) 2010 Charlie Robbins
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* MIT LICENCE
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*/
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'use strict';
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const isStream = require('is-stream');
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const { MESSAGE } = require('triple-beam');
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const os = require('os');
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const TransportStream = require('winston-transport');
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/**
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* Transport for outputting to any arbitrary stream.
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* @type {Stream}
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* @extends {TransportStream}
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*/
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module.exports = class Stream extends TransportStream {
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/**
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* Constructor function for the Console transport object responsible for
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* persisting log messages and metadata to a terminal or TTY.
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* @param {!Object} [options={}] - Options for this instance.
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*/
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constructor(options = {}) {
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super(options);
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if (!options.stream || !isStream(options.stream)) {
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throw new Error('options.stream is required.');
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}
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// We need to listen for drain events when write() returns false. This can
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// make node mad at times.
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this._stream = options.stream;
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this._stream.setMaxListeners(Infinity);
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this.isObjectMode = options.stream._writableState.objectMode;
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this.eol = (typeof options.eol === 'string') ? options.eol : os.EOL;
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}
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/**
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* Core logging method exposed to Winston.
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* @param {Object} info - TODO: add param description.
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* @param {Function} callback - TODO: add param description.
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* @returns {undefined}
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*/
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log(info, callback) {
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setImmediate(() => this.emit('logged', info));
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if (this.isObjectMode) {
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this._stream.write(info);
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if (callback) {
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callback(); // eslint-disable-line callback-return
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}
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return;
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}
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this._stream.write(`${info[MESSAGE]}${this.eol}`);
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if (callback) {
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callback(); // eslint-disable-line callback-return
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}
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return;
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}
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};
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