add polyfill for Promise.try

packages/backend/src/misc/promise-try.ts

@@ -0,0 +1,34 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { types } from 'node:util';
+
+const hasPromiseTry = Reflect.has(globalThis.Promise, 'try');
+
+/**
+ * Polyfill for https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/try
+ */
+export const promiseTry: PromiseTryFunc = hasPromiseTry ? Promise.try : promiseTryPolyfill;
+
+/**
+ * Takes a callback of any kind (returns or throws, synchronously or asynchronously) and wraps its result in a Promise.
+ */
+export type PromiseTryFunc = <T, U extends unknown[]>(callbackFn: (...args: U) => T | PromiseLike<T>, ...args: U) => Promise<Awaited<T>>;
+
+export function promiseTryPolyfill<T, U extends unknown[]>(callbackFn: (...args: U) => T | PromiseLike<T>, ...args: U): Promise<Awaited<T>> {
+	try {
+		const result = callbackFn(...args);
+		if (types.isPromise(result)) {
+			// async return or throw
+			return result as Promise<Awaited<T>>;
+		}
+		// sync return
+		return Promise.resolve(result);
+	}	catch (err) {
+		// sync throw
+		return Promise.reject(err);
+	}
+}
+