1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
'use strict';
const util = require('util');
function Console(stdout, stderr, ignoreErrors = true) {
if (!(this instanceof Console)) {
return new Console(stdout, stderr, ignoreErrors);
}
if (!stdout || typeof stdout.write !== 'function') {
throw new TypeError('Console expects a writable stream instance');
}
if (!stderr) {
stderr = stdout;
} else if (typeof stderr.write !== 'function') {
throw new TypeError('Console expects writable stream instances');
}
var prop = {
writable: true,
enumerable: false,
configurable: true
};
prop.value = stdout;
Object.defineProperty(this, '_stdout', prop);
prop.value = stderr;
Object.defineProperty(this, '_stderr', prop);
prop.value = ignoreErrors;
Object.defineProperty(this, '_ignoreErrors', prop);
prop.value = new Map();
Object.defineProperty(this, '_times', prop);
prop.value = createWriteErrorHandler(stdout);
Object.defineProperty(this, '_stdoutErrorHandler', prop);
prop.value = createWriteErrorHandler(stderr);
Object.defineProperty(this, '_stderrErrorHandler', prop);
// bind the prototype functions to this Console instance
var keys = Object.keys(Console.prototype);
for (var v = 0; v < keys.length; v++) {
var k = keys[v];
this[k] = this[k].bind(this);
}
}
// Make a function that can serve as the callback passed to `stream.write()`.
function createWriteErrorHandler(stream) {
return (err) => {
// This conditional evaluates to true if and only if there was an error
// that was not already emitted (which happens when the _write callback
// is invoked asynchronously).
if (err && !stream._writableState.errorEmitted) {
// If there was an error, it will be emitted on `stream` as
// an `error` event. Adding a `once` listener will keep that error
// from becoming an uncaught exception, but since the handler is
// removed after the event, non-console.* writes won’t be affected.
stream.once('error', noop);
}
};
}
function write(ignoreErrors, stream, string, errorhandler) {
if (!ignoreErrors) return stream.write(string);
// There may be an error occurring synchronously (e.g. for files or TTYs
// on POSIX systems) or asynchronously (e.g. pipes on POSIX systems), so
// handle both situations.
try {
// Add and later remove a noop error handler to catch synchronous errors.
stream.once('error', noop);
stream.write(string, errorhandler);
} catch (e) {
// Sorry, there’s no proper way to pass along the error here.
} finally {
stream.removeListener('error', noop);
}
}
// As of v8 5.0.71.32, the combination of rest param, template string
// and .apply(null, args) benchmarks consistently faster than using
// the spread operator when calling util.format.
Console.prototype.log = function log(...args) {
write(this._ignoreErrors,
this._stdout,
`${util.format.apply(null, args)}\n`,
this._stdoutErrorHandler);
};
Console.prototype.info = Console.prototype.log;
Console.prototype.warn = function warn(...args) {
write(this._ignoreErrors,
this._stderr,
`${util.format.apply(null, args)}\n`,
this._stderrErrorHandler);
};
Console.prototype.error = Console.prototype.warn;
Console.prototype.dir = function dir(object, options) {
options = Object.assign({customInspect: false}, options);
write(this._ignoreErrors, this._stdout, `${util.inspect(object, options)}\n`);
};
Console.prototype.time = function time(label) {
this._times.set(label, process.hrtime());
};
Console.prototype.timeEnd = function timeEnd(label) {
const time = this._times.get(label);
if (!time) {
process.emitWarning(`No such label '${label}' for console.timeEnd()`);
return;
}
const duration = process.hrtime(time);
const ms = duration[0] * 1000 + duration[1] / 1e6;
this.log('%s: %sms', label, ms.toFixed(3));
this._times.delete(label);
};
Console.prototype.trace = function trace(...args) {
// TODO probably can to do this better with V8's debug object once that is
// exposed.
var err = new Error();
err.name = 'Trace';
err.message = util.format.apply(null, args);
Error.captureStackTrace(err, trace);
this.error(err.stack);
};
Console.prototype.assert = function assert(expression, ...args) {
if (!expression) {
require('assert').ok(false, util.format.apply(null, args));
}
};
module.exports = new Console(process.stdout, process.stderr);
module.exports.Console = Console;
function noop() {}
|
