Add awaitAll

frontend/sync-client/src/utils/await-all.test.ts

@@ -0,0 +1,56 @@
+import { test } from "node:test";
+import assert from "node:assert";
+import { awaitAll } from "./await-all";
+
+void test("awaitAll resolves promises of the same type", async () => {
+	const promises = [
+		Promise.resolve(1),
+		Promise.resolve(2),
+		Promise.resolve(3)
+	];
+
+	const results = await awaitAll(promises);
+	assert.deepStrictEqual(results, [1, 2, 3]);
+});
+
+void test("awaitAll resolves promises of different types", async () => {
+	const promises = [
+		Promise.resolve("hello"),
+		Promise.resolve(42),
+		Promise.resolve(true)
+	] as const;
+
+	const results = await awaitAll(promises);
+
+	// Type assertions to verify type inference
+	const str: string = results[0];
+	const num: number = results[1];
+	const bool: boolean = results[2];
+
+	assert.strictEqual(str, "hello");
+	assert.strictEqual(num, 42);
+	assert.strictEqual(bool, true);
+});
+
+void test("awaitAll throws on first rejection", async () => {
+	const error = new Error("Test error");
+	const promises = [
+		Promise.resolve(1),
+		Promise.reject(error),
+		Promise.resolve(3)
+	];
+
+	await assert.rejects(async () => {
+		await awaitAll(promises);
+	}, error);
+});
+
+void test("awaitAll works with async functions", async () => {
+	const asyncString = async (): Promise<string> => "async";
+	const asyncNumber = async (): Promise<number> => 123;
+
+	const results = await awaitAll([asyncString(), asyncNumber()]);
+
+	assert.strictEqual(results[0], "async");
+	assert.strictEqual(results[1], 123);
+});