1  /**
  2   * Module dependencies.
  3   */
  4  
  5  const tty = require('tty');
  6  const util = require('util');
  7  
  8  /**
  9   * This is the Node.js implementation of `debug()`.
 10   */
 11  
 12  exports.init = init;
 13  exports.log = log;
 14  exports.formatArgs = formatArgs;
 15  exports.save = save;
 16  exports.load = load;
 17  exports.useColors = useColors;
 18  exports.destroy = util.deprecate(
 19  	() => {},
 20  	'Instance method `debug.destroy()` is deprecated and no longer does anything. It will be removed in the next major version of `debug`.'
 21  );
 22  
 23  /**
 24   * Colors.
 25   */
 26  
 27  exports.colors = [6, 2, 3, 4, 5, 1];
 28  
 29  try {
 30  	// Optional dependency (as in, doesn't need to be installed, NOT like optionalDependencies in package.json)
 31  	// eslint-disable-next-line import/no-extraneous-dependencies
 32  	const supportsColor = require('supports-color');
 33  
 34  	if (supportsColor && (supportsColor.stderr || supportsColor).level >= 2) {
 35  		exports.colors = [
 36  			20,
 37  			21,
 38  			26,
 39  			27,
 40  			32,
 41  			33,
 42  			38,
 43  			39,
 44  			40,
 45  			41,
 46  			42,
 47  			43,
 48  			44,
 49  			45,
 50  			56,
 51  			57,
 52  			62,
 53  			63,
 54  			68,
 55  			69,
 56  			74,
 57  			75,
 58  			76,
 59  			77,
 60  			78,
 61  			79,
 62  			80,
 63  			81,
 64  			92,
 65  			93,
 66  			98,
 67  			99,
 68  			112,
 69  			113,
 70  			128,
 71  			129,
 72  			134,
 73  			135,
 74  			148,
 75  			149,
 76  			160,
 77  			161,
 78  			162,
 79  			163,
 80  			164,
 81  			165,
 82  			166,
 83  			167,
 84  			168,
 85  			169,
 86  			170,
 87  			171,
 88  			172,
 89  			173,
 90  			178,
 91  			179,
 92  			184,
 93  			185,
 94  			196,
 95  			197,
 96  			198,
 97  			199,
 98  			200,
 99  			201,
100  			202,
101  			203,
102  			204,
103  			205,
104  			206,
105  			207,
106  			208,
107  			209,
108  			214,
109  			215,
110  			220,
111  			221
112  		];
113  	}
114  } catch (error) {
115  	// Swallow - we only care if `supports-color` is available; it doesn't have to be.
116  }
117  
118  /**
119   * Build up the default `inspectOpts` object from the environment variables.
120   *
121   *   $ DEBUG_COLORS=no DEBUG_DEPTH=10 DEBUG_SHOW_HIDDEN=enabled node script.js
122   */
123  
124  exports.inspectOpts = Object.keys(process.env).filter(key => {
125  	return /^debug_/i.test(key);
126  }).reduce((obj, key) => {
127  	// Camel-case
128  	const prop = key
129  		.substring(6)
130  		.toLowerCase()
131  		.replace(/_([a-z])/g, (_, k) => {
132  			return k.toUpperCase();
133  		});
134  
135  	// Coerce string value into JS value
136  	let val = process.env[key];
137  	if (/^(yes|on|true|enabled)$/i.test(val)) {
138  		val = true;
139  	} else if (/^(no|off|false|disabled)$/i.test(val)) {
140  		val = false;
141  	} else if (val === 'null') {
142  		val = null;
143  	} else {
144  		val = Number(val);
145  	}
146  
147  	obj[prop] = val;
148  	return obj;
149  }, {});
150  
151  /**
152   * Is stdout a TTY? Colored output is enabled when `true`.
153   */
154  
155  function useColors() {
156  	return 'colors' in exports.inspectOpts ?
157  		Boolean(exports.inspectOpts.colors) :
158  		tty.isatty(process.stderr.fd);
159  }
160  
161  /**
162   * Adds ANSI color escape codes if enabled.
163   *
164   * @api public
165   */
166  
167  function formatArgs(args) {
168  	const {namespace: name, useColors} = this;
169  
170  	if (useColors) {
171  		const c = this.color;
172  		const colorCode = '\u001B[3' + (c < 8 ? c : '8;5;' + c);
173  		const prefix = `  ${colorCode};1m${name} \u001B[0m`;
174  
175  		args[0] = prefix + args[0].split('\n').join('\n' + prefix);
176  		args.push(colorCode + 'm+' + module.exports.humanize(this.diff) + '\u001B[0m');
177  	} else {
178  		args[0] = getDate() + name + ' ' + args[0];
179  	}
180  }
181  
182  function getDate() {
183  	if (exports.inspectOpts.hideDate) {
184  		return '';
185  	}
186  	return new Date().toISOString() + ' ';
187  }
188  
189  /**
190   * Invokes `util.formatWithOptions()` with the specified arguments and writes to stderr.
191   */
192  
193  function log(...args) {
194  	return process.stderr.write(util.formatWithOptions(exports.inspectOpts, ...args) + '\n');
195  }
196  
197  /**
198   * Save `namespaces`.
199   *
200   * @param {String} namespaces
201   * @api private
202   */
203  function save(namespaces) {
204  	if (namespaces) {
205  		process.env.DEBUG = namespaces;
206  	} else {
207  		// If you set a process.env field to null or undefined, it gets cast to the
208  		// string 'null' or 'undefined'. Just delete instead.
209  		delete process.env.DEBUG;
210  	}
211  }
212  
213  /**
214   * Load `namespaces`.
215   *
216   * @return {String} returns the previously persisted debug modes
217   * @api private
218   */
219  
220  function load() {
221  	return process.env.DEBUG;
222  }
223  
224  /**
225   * Init logic for `debug` instances.
226   *
227   * Create a new `inspectOpts` object in case `useColors` is set
228   * differently for a particular `debug` instance.
229   */
230  
231  function init(debug) {
232  	debug.inspectOpts = {};
233  
234  	const keys = Object.keys(exports.inspectOpts);
235  	for (let i = 0; i < keys.length; i++) {
236  		debug.inspectOpts[keys[i]] = exports.inspectOpts[keys[i]];
237  	}
238  }
239  
240  module.exports = require('./common')(exports);
241  
242  const {formatters} = module.exports;
243  
244  /**
245   * Map %o to `util.inspect()`, all on a single line.
246   */
247  
248  formatters.o = function (v) {
249  	this.inspectOpts.colors = this.useColors;
250  	return util.inspect(v, this.inspectOpts)
251  		.split('\n')
252  		.map(str => str.trim())
253  		.join(' ');
254  };
255  
256  /**
257   * Map %O to `util.inspect()`, allowing multiple lines if needed.
258   */
259  
260  formatters.O = function (v) {
261  	this.inspectOpts.colors = this.useColors;
262  	return util.inspect(v, this.inspectOpts);
263  };