Musique/node_modules/when/lib/makePromise.js
2021-12-04 20:00:33 +01:00

955 lines
23 KiB
JavaScript

/** @license MIT License (c) copyright 2010-2014 original author or authors */
/** @author Brian Cavalier */
/** @author John Hann */
(function(define) { 'use strict';
define(function() {
return function makePromise(environment) {
var tasks = environment.scheduler;
var emitRejection = initEmitRejection();
var objectCreate = Object.create ||
function(proto) {
function Child() {}
Child.prototype = proto;
return new Child();
};
/**
* Create a promise whose fate is determined by resolver
* @constructor
* @returns {Promise} promise
* @name Promise
*/
function Promise(resolver, handler) {
this._handler = resolver === Handler ? handler : init(resolver);
}
/**
* Run the supplied resolver
* @param resolver
* @returns {Pending}
*/
function init(resolver) {
var handler = new Pending();
try {
resolver(promiseResolve, promiseReject, promiseNotify);
} catch (e) {
promiseReject(e);
}
return handler;
/**
* Transition from pre-resolution state to post-resolution state, notifying
* all listeners of the ultimate fulfillment or rejection
* @param {*} x resolution value
*/
function promiseResolve (x) {
handler.resolve(x);
}
/**
* Reject this promise with reason, which will be used verbatim
* @param {Error|*} reason rejection reason, strongly suggested
* to be an Error type
*/
function promiseReject (reason) {
handler.reject(reason);
}
/**
* @deprecated
* Issue a progress event, notifying all progress listeners
* @param {*} x progress event payload to pass to all listeners
*/
function promiseNotify (x) {
handler.notify(x);
}
}
// Creation
Promise.resolve = resolve;
Promise.reject = reject;
Promise.never = never;
Promise._defer = defer;
Promise._handler = getHandler;
/**
* Returns a trusted promise. If x is already a trusted promise, it is
* returned, otherwise returns a new trusted Promise which follows x.
* @param {*} x
* @return {Promise} promise
*/
function resolve(x) {
return isPromise(x) ? x
: new Promise(Handler, new Async(getHandler(x)));
}
/**
* Return a reject promise with x as its reason (x is used verbatim)
* @param {*} x
* @returns {Promise} rejected promise
*/
function reject(x) {
return new Promise(Handler, new Async(new Rejected(x)));
}
/**
* Return a promise that remains pending forever
* @returns {Promise} forever-pending promise.
*/
function never() {
return foreverPendingPromise; // Should be frozen
}
/**
* Creates an internal {promise, resolver} pair
* @private
* @returns {Promise}
*/
function defer() {
return new Promise(Handler, new Pending());
}
// Transformation and flow control
/**
* Transform this promise's fulfillment value, returning a new Promise
* for the transformed result. If the promise cannot be fulfilled, onRejected
* is called with the reason. onProgress *may* be called with updates toward
* this promise's fulfillment.
* @param {function=} onFulfilled fulfillment handler
* @param {function=} onRejected rejection handler
* @param {function=} onProgress @deprecated progress handler
* @return {Promise} new promise
*/
Promise.prototype.then = function(onFulfilled, onRejected, onProgress) {
var parent = this._handler;
var state = parent.join().state();
if ((typeof onFulfilled !== 'function' && state > 0) ||
(typeof onRejected !== 'function' && state < 0)) {
// Short circuit: value will not change, simply share handler
return new this.constructor(Handler, parent);
}
var p = this._beget();
var child = p._handler;
parent.chain(child, parent.receiver, onFulfilled, onRejected, onProgress);
return p;
};
/**
* If this promise cannot be fulfilled due to an error, call onRejected to
* handle the error. Shortcut for .then(undefined, onRejected)
* @param {function?} onRejected
* @return {Promise}
*/
Promise.prototype['catch'] = function(onRejected) {
return this.then(void 0, onRejected);
};
/**
* Creates a new, pending promise of the same type as this promise
* @private
* @returns {Promise}
*/
Promise.prototype._beget = function() {
return begetFrom(this._handler, this.constructor);
};
function begetFrom(parent, Promise) {
var child = new Pending(parent.receiver, parent.join().context);
return new Promise(Handler, child);
}
// Array combinators
Promise.all = all;
Promise.race = race;
Promise._traverse = traverse;
/**
* Return a promise that will fulfill when all promises in the
* input array have fulfilled, or will reject when one of the
* promises rejects.
* @param {array} promises array of promises
* @returns {Promise} promise for array of fulfillment values
*/
function all(promises) {
return traverseWith(snd, null, promises);
}
/**
* Array<Promise<X>> -> Promise<Array<f(X)>>
* @private
* @param {function} f function to apply to each promise's value
* @param {Array} promises array of promises
* @returns {Promise} promise for transformed values
*/
function traverse(f, promises) {
return traverseWith(tryCatch2, f, promises);
}
function traverseWith(tryMap, f, promises) {
var handler = typeof f === 'function' ? mapAt : settleAt;
var resolver = new Pending();
var pending = promises.length >>> 0;
var results = new Array(pending);
for (var i = 0, x; i < promises.length && !resolver.resolved; ++i) {
x = promises[i];
if (x === void 0 && !(i in promises)) {
--pending;
continue;
}
traverseAt(promises, handler, i, x, resolver);
}
if(pending === 0) {
resolver.become(new Fulfilled(results));
}
return new Promise(Handler, resolver);
function mapAt(i, x, resolver) {
if(!resolver.resolved) {
traverseAt(promises, settleAt, i, tryMap(f, x, i), resolver);
}
}
function settleAt(i, x, resolver) {
results[i] = x;
if(--pending === 0) {
resolver.become(new Fulfilled(results));
}
}
}
function traverseAt(promises, handler, i, x, resolver) {
if (maybeThenable(x)) {
var h = getHandlerMaybeThenable(x);
var s = h.state();
if (s === 0) {
h.fold(handler, i, void 0, resolver);
} else if (s > 0) {
handler(i, h.value, resolver);
} else {
resolver.become(h);
visitRemaining(promises, i+1, h);
}
} else {
handler(i, x, resolver);
}
}
Promise._visitRemaining = visitRemaining;
function visitRemaining(promises, start, handler) {
for(var i=start; i<promises.length; ++i) {
markAsHandled(getHandler(promises[i]), handler);
}
}
function markAsHandled(h, handler) {
if(h === handler) {
return;
}
var s = h.state();
if(s === 0) {
h.visit(h, void 0, h._unreport);
} else if(s < 0) {
h._unreport();
}
}
/**
* Fulfill-reject competitive race. Return a promise that will settle
* to the same state as the earliest input promise to settle.
*
* WARNING: The ES6 Promise spec requires that race()ing an empty array
* must return a promise that is pending forever. This implementation
* returns a singleton forever-pending promise, the same singleton that is
* returned by Promise.never(), thus can be checked with ===
*
* @param {array} promises array of promises to race
* @returns {Promise} if input is non-empty, a promise that will settle
* to the same outcome as the earliest input promise to settle. if empty
* is empty, returns a promise that will never settle.
*/
function race(promises) {
if(typeof promises !== 'object' || promises === null) {
return reject(new TypeError('non-iterable passed to race()'));
}
// Sigh, race([]) is untestable unless we return *something*
// that is recognizable without calling .then() on it.
return promises.length === 0 ? never()
: promises.length === 1 ? resolve(promises[0])
: runRace(promises);
}
function runRace(promises) {
var resolver = new Pending();
var i, x, h;
for(i=0; i<promises.length; ++i) {
x = promises[i];
if (x === void 0 && !(i in promises)) {
continue;
}
h = getHandler(x);
if(h.state() !== 0) {
resolver.become(h);
visitRemaining(promises, i+1, h);
break;
} else {
h.visit(resolver, resolver.resolve, resolver.reject);
}
}
return new Promise(Handler, resolver);
}
// Promise internals
// Below this, everything is @private
/**
* Get an appropriate handler for x, without checking for cycles
* @param {*} x
* @returns {object} handler
*/
function getHandler(x) {
if(isPromise(x)) {
return x._handler.join();
}
return maybeThenable(x) ? getHandlerUntrusted(x) : new Fulfilled(x);
}
/**
* Get a handler for thenable x.
* NOTE: You must only call this if maybeThenable(x) == true
* @param {object|function|Promise} x
* @returns {object} handler
*/
function getHandlerMaybeThenable(x) {
return isPromise(x) ? x._handler.join() : getHandlerUntrusted(x);
}
/**
* Get a handler for potentially untrusted thenable x
* @param {*} x
* @returns {object} handler
*/
function getHandlerUntrusted(x) {
try {
var untrustedThen = x.then;
return typeof untrustedThen === 'function'
? new Thenable(untrustedThen, x)
: new Fulfilled(x);
} catch(e) {
return new Rejected(e);
}
}
/**
* Handler for a promise that is pending forever
* @constructor
*/
function Handler() {}
Handler.prototype.when
= Handler.prototype.become
= Handler.prototype.notify // deprecated
= Handler.prototype.fail
= Handler.prototype._unreport
= Handler.prototype._report
= noop;
Handler.prototype._state = 0;
Handler.prototype.state = function() {
return this._state;
};
/**
* Recursively collapse handler chain to find the handler
* nearest to the fully resolved value.
* @returns {object} handler nearest the fully resolved value
*/
Handler.prototype.join = function() {
var h = this;
while(h.handler !== void 0) {
h = h.handler;
}
return h;
};
Handler.prototype.chain = function(to, receiver, fulfilled, rejected, progress) {
this.when({
resolver: to,
receiver: receiver,
fulfilled: fulfilled,
rejected: rejected,
progress: progress
});
};
Handler.prototype.visit = function(receiver, fulfilled, rejected, progress) {
this.chain(failIfRejected, receiver, fulfilled, rejected, progress);
};
Handler.prototype.fold = function(f, z, c, to) {
this.when(new Fold(f, z, c, to));
};
/**
* Handler that invokes fail() on any handler it becomes
* @constructor
*/
function FailIfRejected() {}
inherit(Handler, FailIfRejected);
FailIfRejected.prototype.become = function(h) {
h.fail();
};
var failIfRejected = new FailIfRejected();
/**
* Handler that manages a queue of consumers waiting on a pending promise
* @constructor
*/
function Pending(receiver, inheritedContext) {
Promise.createContext(this, inheritedContext);
this.consumers = void 0;
this.receiver = receiver;
this.handler = void 0;
this.resolved = false;
}
inherit(Handler, Pending);
Pending.prototype._state = 0;
Pending.prototype.resolve = function(x) {
this.become(getHandler(x));
};
Pending.prototype.reject = function(x) {
if(this.resolved) {
return;
}
this.become(new Rejected(x));
};
Pending.prototype.join = function() {
if (!this.resolved) {
return this;
}
var h = this;
while (h.handler !== void 0) {
h = h.handler;
if (h === this) {
return this.handler = cycle();
}
}
return h;
};
Pending.prototype.run = function() {
var q = this.consumers;
var handler = this.handler;
this.handler = this.handler.join();
this.consumers = void 0;
for (var i = 0; i < q.length; ++i) {
handler.when(q[i]);
}
};
Pending.prototype.become = function(handler) {
if(this.resolved) {
return;
}
this.resolved = true;
this.handler = handler;
if(this.consumers !== void 0) {
tasks.enqueue(this);
}
if(this.context !== void 0) {
handler._report(this.context);
}
};
Pending.prototype.when = function(continuation) {
if(this.resolved) {
tasks.enqueue(new ContinuationTask(continuation, this.handler));
} else {
if(this.consumers === void 0) {
this.consumers = [continuation];
} else {
this.consumers.push(continuation);
}
}
};
/**
* @deprecated
*/
Pending.prototype.notify = function(x) {
if(!this.resolved) {
tasks.enqueue(new ProgressTask(x, this));
}
};
Pending.prototype.fail = function(context) {
var c = typeof context === 'undefined' ? this.context : context;
this.resolved && this.handler.join().fail(c);
};
Pending.prototype._report = function(context) {
this.resolved && this.handler.join()._report(context);
};
Pending.prototype._unreport = function() {
this.resolved && this.handler.join()._unreport();
};
/**
* Wrap another handler and force it into a future stack
* @param {object} handler
* @constructor
*/
function Async(handler) {
this.handler = handler;
}
inherit(Handler, Async);
Async.prototype.when = function(continuation) {
tasks.enqueue(new ContinuationTask(continuation, this));
};
Async.prototype._report = function(context) {
this.join()._report(context);
};
Async.prototype._unreport = function() {
this.join()._unreport();
};
/**
* Handler that wraps an untrusted thenable and assimilates it in a future stack
* @param {function} then
* @param {{then: function}} thenable
* @constructor
*/
function Thenable(then, thenable) {
Pending.call(this);
tasks.enqueue(new AssimilateTask(then, thenable, this));
}
inherit(Pending, Thenable);
/**
* Handler for a fulfilled promise
* @param {*} x fulfillment value
* @constructor
*/
function Fulfilled(x) {
Promise.createContext(this);
this.value = x;
}
inherit(Handler, Fulfilled);
Fulfilled.prototype._state = 1;
Fulfilled.prototype.fold = function(f, z, c, to) {
runContinuation3(f, z, this, c, to);
};
Fulfilled.prototype.when = function(cont) {
runContinuation1(cont.fulfilled, this, cont.receiver, cont.resolver);
};
var errorId = 0;
/**
* Handler for a rejected promise
* @param {*} x rejection reason
* @constructor
*/
function Rejected(x) {
Promise.createContext(this);
this.id = ++errorId;
this.value = x;
this.handled = false;
this.reported = false;
this._report();
}
inherit(Handler, Rejected);
Rejected.prototype._state = -1;
Rejected.prototype.fold = function(f, z, c, to) {
to.become(this);
};
Rejected.prototype.when = function(cont) {
if(typeof cont.rejected === 'function') {
this._unreport();
}
runContinuation1(cont.rejected, this, cont.receiver, cont.resolver);
};
Rejected.prototype._report = function(context) {
tasks.afterQueue(new ReportTask(this, context));
};
Rejected.prototype._unreport = function() {
if(this.handled) {
return;
}
this.handled = true;
tasks.afterQueue(new UnreportTask(this));
};
Rejected.prototype.fail = function(context) {
this.reported = true;
emitRejection('unhandledRejection', this);
Promise.onFatalRejection(this, context === void 0 ? this.context : context);
};
function ReportTask(rejection, context) {
this.rejection = rejection;
this.context = context;
}
ReportTask.prototype.run = function() {
if(!this.rejection.handled && !this.rejection.reported) {
this.rejection.reported = true;
emitRejection('unhandledRejection', this.rejection) ||
Promise.onPotentiallyUnhandledRejection(this.rejection, this.context);
}
};
function UnreportTask(rejection) {
this.rejection = rejection;
}
UnreportTask.prototype.run = function() {
if(this.rejection.reported) {
emitRejection('rejectionHandled', this.rejection) ||
Promise.onPotentiallyUnhandledRejectionHandled(this.rejection);
}
};
// Unhandled rejection hooks
// By default, everything is a noop
Promise.createContext
= Promise.enterContext
= Promise.exitContext
= Promise.onPotentiallyUnhandledRejection
= Promise.onPotentiallyUnhandledRejectionHandled
= Promise.onFatalRejection
= noop;
// Errors and singletons
var foreverPendingHandler = new Handler();
var foreverPendingPromise = new Promise(Handler, foreverPendingHandler);
function cycle() {
return new Rejected(new TypeError('Promise cycle'));
}
// Task runners
/**
* Run a single consumer
* @constructor
*/
function ContinuationTask(continuation, handler) {
this.continuation = continuation;
this.handler = handler;
}
ContinuationTask.prototype.run = function() {
this.handler.join().when(this.continuation);
};
/**
* Run a queue of progress handlers
* @constructor
*/
function ProgressTask(value, handler) {
this.handler = handler;
this.value = value;
}
ProgressTask.prototype.run = function() {
var q = this.handler.consumers;
if(q === void 0) {
return;
}
for (var c, i = 0; i < q.length; ++i) {
c = q[i];
runNotify(c.progress, this.value, this.handler, c.receiver, c.resolver);
}
};
/**
* Assimilate a thenable, sending it's value to resolver
* @param {function} then
* @param {object|function} thenable
* @param {object} resolver
* @constructor
*/
function AssimilateTask(then, thenable, resolver) {
this._then = then;
this.thenable = thenable;
this.resolver = resolver;
}
AssimilateTask.prototype.run = function() {
var h = this.resolver;
tryAssimilate(this._then, this.thenable, _resolve, _reject, _notify);
function _resolve(x) { h.resolve(x); }
function _reject(x) { h.reject(x); }
function _notify(x) { h.notify(x); }
};
function tryAssimilate(then, thenable, resolve, reject, notify) {
try {
then.call(thenable, resolve, reject, notify);
} catch (e) {
reject(e);
}
}
/**
* Fold a handler value with z
* @constructor
*/
function Fold(f, z, c, to) {
this.f = f; this.z = z; this.c = c; this.to = to;
this.resolver = failIfRejected;
this.receiver = this;
}
Fold.prototype.fulfilled = function(x) {
this.f.call(this.c, this.z, x, this.to);
};
Fold.prototype.rejected = function(x) {
this.to.reject(x);
};
Fold.prototype.progress = function(x) {
this.to.notify(x);
};
// Other helpers
/**
* @param {*} x
* @returns {boolean} true iff x is a trusted Promise
*/
function isPromise(x) {
return x instanceof Promise;
}
/**
* Test just enough to rule out primitives, in order to take faster
* paths in some code
* @param {*} x
* @returns {boolean} false iff x is guaranteed *not* to be a thenable
*/
function maybeThenable(x) {
return (typeof x === 'object' || typeof x === 'function') && x !== null;
}
function runContinuation1(f, h, receiver, next) {
if(typeof f !== 'function') {
return next.become(h);
}
Promise.enterContext(h);
tryCatchReject(f, h.value, receiver, next);
Promise.exitContext();
}
function runContinuation3(f, x, h, receiver, next) {
if(typeof f !== 'function') {
return next.become(h);
}
Promise.enterContext(h);
tryCatchReject3(f, x, h.value, receiver, next);
Promise.exitContext();
}
/**
* @deprecated
*/
function runNotify(f, x, h, receiver, next) {
if(typeof f !== 'function') {
return next.notify(x);
}
Promise.enterContext(h);
tryCatchReturn(f, x, receiver, next);
Promise.exitContext();
}
function tryCatch2(f, a, b) {
try {
return f(a, b);
} catch(e) {
return reject(e);
}
}
/**
* Return f.call(thisArg, x), or if it throws return a rejected promise for
* the thrown exception
*/
function tryCatchReject(f, x, thisArg, next) {
try {
next.become(getHandler(f.call(thisArg, x)));
} catch(e) {
next.become(new Rejected(e));
}
}
/**
* Same as above, but includes the extra argument parameter.
*/
function tryCatchReject3(f, x, y, thisArg, next) {
try {
f.call(thisArg, x, y, next);
} catch(e) {
next.become(new Rejected(e));
}
}
/**
* @deprecated
* Return f.call(thisArg, x), or if it throws, *return* the exception
*/
function tryCatchReturn(f, x, thisArg, next) {
try {
next.notify(f.call(thisArg, x));
} catch(e) {
next.notify(e);
}
}
function inherit(Parent, Child) {
Child.prototype = objectCreate(Parent.prototype);
Child.prototype.constructor = Child;
}
function snd(x, y) {
return y;
}
function noop() {}
function hasCustomEvent() {
if(typeof CustomEvent === 'function') {
try {
var ev = new CustomEvent('unhandledRejection');
return ev instanceof CustomEvent;
} catch (ignoredException) {}
}
return false;
}
function hasInternetExplorerCustomEvent() {
if(typeof document !== 'undefined' && typeof document.createEvent === 'function') {
try {
// Try to create one event to make sure it's supported
var ev = document.createEvent('CustomEvent');
ev.initCustomEvent('eventType', false, true, {});
return true;
} catch (ignoredException) {}
}
return false;
}
function initEmitRejection() {
/*global process, self, CustomEvent*/
if(typeof process !== 'undefined' && process !== null
&& typeof process.emit === 'function') {
// Returning falsy here means to call the default
// onPotentiallyUnhandledRejection API. This is safe even in
// browserify since process.emit always returns falsy in browserify:
// https://github.com/defunctzombie/node-process/blob/master/browser.js#L40-L46
return function(type, rejection) {
return type === 'unhandledRejection'
? process.emit(type, rejection.value, rejection)
: process.emit(type, rejection);
};
} else if(typeof self !== 'undefined' && hasCustomEvent()) {
return (function (self, CustomEvent) {
return function (type, rejection) {
var ev = new CustomEvent(type, {
detail: {
reason: rejection.value,
key: rejection
},
bubbles: false,
cancelable: true
});
return !self.dispatchEvent(ev);
};
}(self, CustomEvent));
} else if(typeof self !== 'undefined' && hasInternetExplorerCustomEvent()) {
return (function(self, document) {
return function(type, rejection) {
var ev = document.createEvent('CustomEvent');
ev.initCustomEvent(type, false, true, {
reason: rejection.value,
key: rejection
});
return !self.dispatchEvent(ev);
};
}(self, document));
}
return noop;
}
return Promise;
};
});
}(typeof define === 'function' && define.amd ? define : function(factory) { module.exports = factory(); }));