core-js
Version:
Standard library
313 lines (307 loc) • 10.3 kB
JavaScript
;
var LIBRARY = require('./_library')
, global = require('./_global')
, ctx = require('./_ctx')
, classof = require('./_classof')
, $export = require('./_export')
, isObject = require('./_is-object')
, anObject = require('./_an-object')
, aFunction = require('./_a-function')
, anInstance = require('./_an-instance')
, forOf = require('./_for-of')
, from = require('./_array-from-iterable')
, setProto = require('./_set-proto').set
, speciesConstructor = require('./_species-constructor')
, task = require('./_task').set
, microtask = require('./_microtask')
, PROMISE = 'Promise'
, TypeError = global.TypeError
, process = global.process
, $Promise = global[PROMISE]
, isNode = classof(process) == 'process'
, empty = function(){ /* empty */ }
, Internal, GenericPromiseCapability, Wrapper;
var testResolve = function(sub){
var test = new $Promise(empty), promise;
if(sub)test.constructor = function(exec){
exec(empty, empty);
};
(promise = $Promise.resolve(test))['catch'](empty);
return promise === test;
};
var USE_NATIVE = function(){
var works = false;
var SubPromise = function(x){
var self = new $Promise(x);
setProto(self, SubPromise.prototype);
return self;
};
try {
works = $Promise && $Promise.resolve && testResolve();
setProto(SubPromise, $Promise);
SubPromise.prototype = require('./_object-create')($Promise.prototype, {constructor: {value: SubPromise}});
// actual Firefox has broken subclass support, test that
if(!(SubPromise.resolve(5).then(empty) instanceof SubPromise)){
works = false;
}
// V8 4.8- bug, https://code.google.com/p/v8/issues/detail?id=4162
if(works && require('./_descriptors')){
var thenableThenGotten = false;
$Promise.resolve(require('./_object-dp').f({}, 'then', {
get: function(){ thenableThenGotten = true; }
}));
works = thenableThenGotten;
}
} catch(e){ works = false; }
return !!works;
}();
// helpers
var sameConstructor = function(a, b){
// with library wrapper special case
return a === b || a === $Promise && b === Wrapper;
};
var isThenable = function(it){
var then;
return isObject(it) && typeof (then = it.then) == 'function' ? then : false;
};
var newPromiseCapability = function(C){
return sameConstructor($Promise, C)
? new PromiseCapability(C)
: new GenericPromiseCapability(C);
};
var PromiseCapability = GenericPromiseCapability = function(C){
var resolve, reject;
this.promise = new C(function($$resolve, $$reject){
if(resolve !== undefined || reject !== undefined)throw TypeError('Bad Promise constructor');
resolve = $$resolve;
reject = $$reject;
});
this.resolve = aFunction(resolve);
this.reject = aFunction(reject);
};
var perform = function(exec){
try {
exec();
} catch(e){
return {error: e};
}
};
var notify = function(promise, isReject){
if(promise._n)return;
promise._n = true;
var chain = promise._c;
microtask(function(){
var value = promise._v
, ok = promise._s == 1
, i = 0;
var run = function(reaction){
var handler = ok ? reaction.ok : reaction.fail
, resolve = reaction.resolve
, reject = reaction.reject
, result, then;
try {
if(handler){
if(!ok){
if(promise._h == 2)onHandleUnhandled(promise);
promise._h = 1;
}
result = handler === true ? value : handler(value);
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){
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(){
if(isUnhandled(promise)){
var value = promise._v
, handler, console;
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);
} promise._h = 2;
} promise._a = undefined;
});
};
var isUnhandled = function(promise){
var chain = promise._a || promise._c
, i = 0
, reaction;
if(promise._h == 1)return false;
while(chain.length > i){
reaction = chain[i++];
if(reaction.fail || !isUnhandled(reaction.promise))return false;
} return true;
};
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 $resolve = function(value){
var promise = this
, then;
if(promise._d)return;
promise._d = true;
promise = promise._w || promise; // unwrap
try {
if(promise === value)throw TypeError("Promise can't be resolved itself");
if(then = isThenable(value)){
microtask(function(){
var wrapper = {_w: promise, _d: false}; // wrap
try {
then.call(value, ctx($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){
$reject.call(this, err);
}
};
Internal = function Promise(executor){
this._c = []; // <- awaiting reactions
this._a = undefined; // <- checked in isUnhandled reactions
this._s = 0; // <- state
this._d = false; // <- done
this._v = undefined; // <- value
this._h = 0; // <- rejection state, 0 - default, 1 - handled, 2 - unhandled
this._n = false; // <- notify
};
Internal.prototype = require('./_redefine-all')($Promise.prototype, {
// 25.4.5.3 Promise.prototype.then(onFulfilled, onRejected)
then: function then(onFulfilled, onRejected){
var reaction = newPromiseCapability(speciesConstructor(this, $Promise));
reaction.ok = typeof onFulfilled == 'function' ? onFulfilled : true;
reaction.fail = typeof onRejected == 'function' && onRejected;
this._c.push(reaction);
if(this._a)this._a.push(reaction);
if(this._s)notify(this, false);
return reaction.promise;
},
// 25.4.5.1 Promise.prototype.catch(onRejected)
'catch': function(onRejected){
return this.then(undefined, onRejected);
}
});
PromiseCapability = function(){
var promise = new Internal;
this.promise = promise;
this.resolve = ctx($resolve, promise, 1);
this.reject = ctx($reject, promise, 1);
};
}
$export($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)
, $$reject = capability.reject;
$$reject(r);
return capability.promise;
}
});
$export($export.S + $export.F * (LIBRARY || !USE_NATIVE || testResolve(true)), PROMISE, {
// 25.4.4.6 Promise.resolve(x)
resolve: function resolve(x){
// instanceof instead of internal slot check because we should fix it without replacement native Promise core
if(x instanceof $Promise && sameConstructor(x.constructor, this))return x;
var capability = newPromiseCapability(this)
, $$resolve = capability.resolve;
$$resolve(x);
return capability.promise;
}
});
$export($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
, capability = newPromiseCapability(C)
, resolve = capability.resolve
, reject = capability.reject;
var abrupt = perform(function(){
var values = from(iterable)
, remaining = values.length
, results = Array(remaining);
var f = function(promise, index){
var alreadyCalled = false;
C.resolve(promise).then(function(value){
if(alreadyCalled)return;
alreadyCalled = true;
results[index] = value;
--remaining || resolve(results);
}, reject);
};
if(remaining)for(var i = 0, l = values.length; l > i; i++)f(values[i], i);
else resolve(results);
});
if(abrupt)reject(abrupt.error);
return capability.promise;
},
// 25.4.4.4 Promise.race(iterable)
race: function race(iterable){
var C = this
, capability = newPromiseCapability(C)
, reject = capability.reject;
var abrupt = perform(function(){
forOf(iterable, false, function(promise){
C.resolve(promise).then(capability.resolve, reject);
});
});
if(abrupt)reject(abrupt.error);
return capability.promise;
}
});