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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
"use strict";
loader.lazyRequireGetter(
this,
"generateUUID",
true
);
loader.lazyRequireGetter(
this,
["entries", "executeSoon", "toObject"],
true
);
const PROMISE = (exports.PROMISE = "@@dispatch/promise");
function promiseMiddleware({ dispatch }) {
return next => action => {
if (!(PROMISE in action)) {
return next(action);
}
// Return the promise so action creators can still compose if they
// want to.
return new Promise((resolve, reject) => {
const promiseInst = action[PROMISE];
const seqId = generateUUID().toString();
// Create a new action that doesn't have the promise field and has
// the `seqId` field that represents the sequence id
action = Object.assign(
toObject(entries(action).filter(pair => pair[0] !== PROMISE)),
{ seqId }
);
dispatch(Object.assign({}, action, { status: "start" }));
promiseInst.then(
value => {
executeSoon(() => {
dispatch(
Object.assign({}, action, {
status: "done",
value,
})
);
resolve(value);
});
},
error => {
executeSoon(() => {
dispatch(
Object.assign({}, action, {
status: "error",
error: error.message || error,
})
);
reject(error);
});
}
);
});
};
}
exports.promise = promiseMiddleware;