Current File : //lib/node_modules/npm/node_modules/signal-exit/index.js
// Note: since nyc uses this module to output coverage, any lines
// that are in the direct sync flow of nyc's outputCoverage are
// ignored, since we can never get coverage for them.
var assert = require('assert')
var signals = require('./signals.js')
var EE = require('events')
/* istanbul ignore if */
if (typeof EE !== 'function') {
EE = EE.EventEmitter
}
var emitter
if (process.__signal_exit_emitter__) {
emitter = process.__signal_exit_emitter__
} else {
emitter = process.__signal_exit_emitter__ = new EE()
emitter.count = 0
emitter.emitted = {}
}
// Because this emitter is a global, we have to check to see if a
// previous version of this library failed to enable infinite listeners.
// I know what you're about to say. But literally everything about
// signal-exit is a compromise with evil. Get used to it.
if (!emitter.infinite) {
emitter.setMaxListeners(Infinity)
emitter.infinite = true
}
module.exports = function (cb, opts) {
assert.equal(typeof cb, 'function', 'a callback must be provided for exit handler')
if (loaded === false) {
load()
}
var ev = 'exit'
if (opts && opts.alwaysLast) {
ev = 'afterexit'
}
var remove = function () {
emitter.removeListener(ev, cb)
if (emitter.listeners('exit').length === 0 &&
emitter.listeners('afterexit').length === 0) {
unload()
}
}
emitter.on(ev, cb)
return remove
}
module.exports.unload = unload
function unload () {
if (!loaded) {
return
}
loaded = false
signals.forEach(function (sig) {
try {
process.removeListener(sig, sigListeners[sig])
} catch (er) {}
})
process.emit = originalProcessEmit
process.reallyExit = originalProcessReallyExit
emitter.count -= 1
}
function emit (event, code, signal) {
if (emitter.emitted[event]) {
return
}
emitter.emitted[event] = true
emitter.emit(event, code, signal)
}
// { <signal>: <listener fn>, ... }
var sigListeners = {}
signals.forEach(function (sig) {
sigListeners[sig] = function listener () {
// If there are no other listeners, an exit is coming!
// Simplest way: remove us and then re-send the signal.
// We know that this will kill the process, so we can
// safely emit now.
var listeners = process.listeners(sig)
if (listeners.length === emitter.count) {
unload()
emit('exit', null, sig)
/* istanbul ignore next */
emit('afterexit', null, sig)
/* istanbul ignore next */
process.kill(process.pid, sig)
}
}
})
module.exports.signals = function () {
return signals
}
module.exports.load = load
var loaded = false
function load () {
if (loaded) {
return
}
loaded = true
// This is the number of onSignalExit's that are in play.
// It's important so that we can count the correct number of
// listeners on signals, and don't wait for the other one to
// handle it instead of us.
emitter.count += 1
signals = signals.filter(function (sig) {
try {
process.on(sig, sigListeners[sig])
return true
} catch (er) {
return false
}
})
process.emit = processEmit
process.reallyExit = processReallyExit
}
var originalProcessReallyExit = process.reallyExit
function processReallyExit (code) {
process.exitCode = code || 0
emit('exit', process.exitCode, null)
/* istanbul ignore next */
emit('afterexit', process.exitCode, null)
/* istanbul ignore next */
originalProcessReallyExit.call(process, process.exitCode)
}
var originalProcessEmit = process.emit
function processEmit (ev, arg) {
if (ev === 'exit') {
if (arg !== undefined) {
process.exitCode = arg
}
var ret = originalProcessEmit.apply(this, arguments)
emit('exit', process.exitCode, null)
/* istanbul ignore next */
emit('afterexit', process.exitCode, null)
return ret
} else {
return originalProcessEmit.apply(this, arguments)
}
}
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