Convert promise utility module to tyepscript

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/utils/promise.ts

@@ -0,0 +1,70 @@
+/*
+Copyright 2019, 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Returns a promise which resolves with a given value after the given number of ms
+export function sleep<T>(ms: number, value: T): Promise<T> {
+    return new Promise((resolve => { setTimeout(resolve, ms, value); }));
+}
+
+// Returns a promise which resolves when the input promise resolves with its value
+// or when the timeout of ms is reached with the value of given timeoutValue
+export async function timeout<T>(promise: Promise<T>, timeoutValue: T, ms: number): Promise<T> {
+    const timeoutPromise = new Promise<T>((resolve) => {
+        const timeoutId = setTimeout(resolve, ms, timeoutValue);
+        promise.then(() => {
+            clearTimeout(timeoutId);
+        });
+    });
+
+    return Promise.race([promise, timeoutPromise]);
+}
+
+export interface IDeferred<T> {
+    resolve: (T) => void;
+    reject: (any) => void;
+    promise: Promise<T>;
+}
+
+// Returns a Deferred
+export function defer<T>(): IDeferred<T> {
+    let resolve;
+    let reject;
+
+    const promise = new Promise<T>((_resolve, _reject) => {
+        resolve = _resolve;
+        reject = _reject;
+    });
+
+    return {resolve, reject, promise};
+}
+
+// Promise.allSettled polyfill until browser support is stable in Firefox
+export function allSettled<T>(promises: Promise<T>[]): Promise<Array<ISettledFulfilled<T> | ISettledRejected>> {
+    if (Promise.allSettled) {
+        return Promise.allSettled<T>(promises);
+    }
+
+    // @ts-ignore - typescript isn't smart enough to see the disjoint here
+    return Promise.all(promises.map((promise) => {
+        return promise.then(value => ({
+            status: "fulfilled",
+            value,
+        })).catch(reason => ({
+            status: "rejected",
+            reason,
+        }));
+    }));
+}