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287 lines
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JavaScript

6 years ago
'use strict';
var LIBRARY = require('./_library');
var global = require('./_global');
var ctx = require('./_ctx');
var classof = require('./_classof');
var $export = require('./_export');
var isObject = require('./_is-object');
var aFunction = require('./_a-function');
var anInstance = require('./_an-instance');
var forOf = require('./_for-of');
var speciesConstructor = require('./_species-constructor');
var task = require('./_task').set;
var microtask = require('./_microtask')();
var newPromiseCapabilityModule = require('./_new-promise-capability');
var perform = require('./_perform');
var userAgent = require('./_user-agent');
var promiseResolve = require('./_promise-resolve');
var PROMISE = 'Promise';
var TypeError = global.TypeError;
var process = global.process;
var versions = process && process.versions;
var v8 = versions && versions.v8 || '';
var $Promise = global[PROMISE];
var isNode = classof(process) == 'process';
var empty = function () { /* empty */ };
var Internal, newGenericPromiseCapability, OwnPromiseCapability, Wrapper;
var newPromiseCapability = newGenericPromiseCapability = newPromiseCapabilityModule.f;
var USE_NATIVE = !!function () {
try {
// correct subclassing with @@species support
var promise = $Promise.resolve(1);
var FakePromise = (promise.constructor = {})[require('./_wks')('species')] = function (exec) {
exec(empty, empty);
};
// unhandled rejections tracking support, NodeJS Promise without it fails @@species test
return (isNode || typeof PromiseRejectionEvent == 'function')
&& promise.then(empty) instanceof FakePromise
// v8 6.6 (Node 10 and Chrome 66) have a bug with resolving custom thenables
// https://bugs.chromium.org/p/chromium/issues/detail?id=830565
// we can't detect it synchronously, so just check versions
&& v8.indexOf('6.6') !== 0
&& userAgent.indexOf('Chrome/66') === -1;
} catch (e) { /* empty */ }
}();
// helpers
var isThenable = function (it) {
var then;
return isObject(it) && typeof (then = it.then) == 'function' ? then : false;
};
var notify = function (promise, isReject) {
if (promise._n) return;
promise._n = true;
var chain = promise._c;
microtask(function () {
var value = promise._v;
var ok = promise._s == 1;
var i = 0;
var run = function (reaction) {
var handler = ok ? reaction.ok : reaction.fail;
var resolve = reaction.resolve;
var reject = reaction.reject;
var domain = reaction.domain;
var result, then, exited;
try {
if (handler) {
if (!ok) {
if (promise._h == 2) onHandleUnhandled(promise);
promise._h = 1;
}
if (handler === true) result = value;
else {
if (domain) domain.enter();
result = handler(value); // may throw
if (domain) {
domain.exit();
exited = true;
}
}
if (result === reaction.promise) {
reject(TypeError('Promise-chain cycle'));
} else if (then = isThenable(result)) {
then.call(result, resolve, reject);
} else resolve(result);
} else reject(value);
} catch (e) {
if (domain && !exited) domain.exit();
reject(e);
}
};
while (chain.length > i) run(chain[i++]); // variable length - can't use forEach
promise._c = [];
promise._n = false;
if (isReject && !promise._h) onUnhandled(promise);
});
};
var onUnhandled = function (promise) {
task.call(global, function () {
var value = promise._v;
var unhandled = isUnhandled(promise);
var result, handler, console;
if (unhandled) {
result = perform(function () {
if (isNode) {
process.emit('unhandledRejection', value, promise);
} else if (handler = global.onunhandledrejection) {
handler({ promise: promise, reason: value });
} else if ((console = global.console) && console.error) {
console.error('Unhandled promise rejection', value);
}
});
// Browsers should not trigger `rejectionHandled` event if it was handled here, NodeJS - should
promise._h = isNode || isUnhandled(promise) ? 2 : 1;
} promise._a = undefined;
if (unhandled && result.e) throw result.v;
});
};
var isUnhandled = function (promise) {
return promise._h !== 1 && (promise._a || promise._c).length === 0;
};
var onHandleUnhandled = function (promise) {
task.call(global, function () {
var handler;
if (isNode) {
process.emit('rejectionHandled', promise);
} else if (handler = global.onrejectionhandled) {
handler({ promise: promise, reason: promise._v });
}
});
};
var $reject = function (value) {
var promise = this;
if (promise._d) return;
promise._d = true;
promise = promise._w || promise; // unwrap
promise._v = value;
promise._s = 2;
if (!promise._a) promise._a = promise._c.slice();
notify(promise, true);
};
var $resolve = function (value) {
var promise = this;
var then;
if (promise._d) return;
promise._d = true;
promise = promise._w || promise; // unwrap
try {
if (promise === value) throw TypeError("Promise can't be resolved itself");
if (then = isThenable(value)) {
microtask(function () {
var wrapper = { _w: promise, _d: false }; // wrap
try {
then.call(value, ctx($resolve, wrapper, 1), ctx($reject, wrapper, 1));
} catch (e) {
$reject.call(wrapper, e);
}
});
} else {
promise._v = value;
promise._s = 1;
notify(promise, false);
}
} catch (e) {
$reject.call({ _w: promise, _d: false }, e); // wrap
}
};
// constructor polyfill
if (!USE_NATIVE) {
// 25.4.3.1 Promise(executor)
$Promise = function Promise(executor) {
anInstance(this, $Promise, PROMISE, '_h');
aFunction(executor);
Internal.call(this);
try {
executor(ctx($resolve, this, 1), ctx($reject, this, 1));
} catch (err) {
$reject.call(this, err);
}
};
// eslint-disable-next-line no-unused-vars
Internal = function Promise(executor) {
this._c = []; // <- awaiting reactions
this._a = undefined; // <- checked in isUnhandled reactions
this._s = 0; // <- state
this._d = false; // <- done
this._v = undefined; // <- value
this._h = 0; // <- rejection state, 0 - default, 1 - handled, 2 - unhandled
this._n = false; // <- notify
};
Internal.prototype = require('./_redefine-all')($Promise.prototype, {
// 25.4.5.3 Promise.prototype.then(onFulfilled, onRejected)
then: function then(onFulfilled, onRejected) {
var reaction = newPromiseCapability(speciesConstructor(this, $Promise));
reaction.ok = typeof onFulfilled == 'function' ? onFulfilled : true;
reaction.fail = typeof onRejected == 'function' && onRejected;
reaction.domain = isNode ? process.domain : undefined;
this._c.push(reaction);
if (this._a) this._a.push(reaction);
if (this._s) notify(this, false);
return reaction.promise;
},
// 25.4.5.1 Promise.prototype.catch(onRejected)
'catch': function (onRejected) {
return this.then(undefined, onRejected);
}
});
OwnPromiseCapability = function () {
var promise = new Internal();
this.promise = promise;
this.resolve = ctx($resolve, promise, 1);
this.reject = ctx($reject, promise, 1);
};
newPromiseCapabilityModule.f = newPromiseCapability = function (C) {
return C === $Promise || C === Wrapper
? new OwnPromiseCapability(C)
: newGenericPromiseCapability(C);
};
}
$export($export.G + $export.W + $export.F * !USE_NATIVE, { Promise: $Promise });
require('./_set-to-string-tag')($Promise, PROMISE);
require('./_set-species')(PROMISE);
Wrapper = require('./_core')[PROMISE];
// statics
$export($export.S + $export.F * !USE_NATIVE, PROMISE, {
// 25.4.4.5 Promise.reject(r)
reject: function reject(r) {
var capability = newPromiseCapability(this);
var $$reject = capability.reject;
$$reject(r);
return capability.promise;
}
});
$export($export.S + $export.F * (LIBRARY || !USE_NATIVE), PROMISE, {
// 25.4.4.6 Promise.resolve(x)
resolve: function resolve(x) {
return promiseResolve(LIBRARY && this === Wrapper ? $Promise : this, x);
}
});
$export($export.S + $export.F * !(USE_NATIVE && require('./_iter-detect')(function (iter) {
$Promise.all(iter)['catch'](empty);
})), PROMISE, {
// 25.4.4.1 Promise.all(iterable)
all: function all(iterable) {
var C = this;
var capability = newPromiseCapability(C);
var resolve = capability.resolve;
var reject = capability.reject;
var result = perform(function () {
var values = [];
var index = 0;
var remaining = 1;
forOf(iterable, false, function (promise) {
var $index = index++;
var alreadyCalled = false;
values.push(undefined);
remaining++;
C.resolve(promise).then(function (value) {
if (alreadyCalled) return;
alreadyCalled = true;
values[$index] = value;
--remaining || resolve(values);
}, reject);
});
--remaining || resolve(values);
});
if (result.e) reject(result.v);
return capability.promise;
},
// 25.4.4.4 Promise.race(iterable)
race: function race(iterable) {
var C = this;
var capability = newPromiseCapability(C);
var reject = capability.reject;
var result = perform(function () {
forOf(iterable, false, function (promise) {
C.resolve(promise).then(capability.resolve, reject);
});
});
if (result.e) reject(result.v);
return capability.promise;
}
});