Fix consecutive non awaited calls (#25)

.github/workflows/main.yml

@@ -11,8 +11,8 @@ jobs:
       matrix:
         node-version:
           - 16
+          - 14
           - 12
-          - 10
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2

index.js

@@ -22,24 +22,24 @@ const pMemoize = (fn, {cachePromiseRejection = false, ...options} = {}) => {
 			return cacheItem.data;
 		}
 
-		const result = fn.apply(this, arguments_);
+		const promise = fn.apply(this, arguments_);
+		cache.set(key, {
+			data: promise,
+			maxAge: Number.POSITIVE_INFINITY
+		});
 
-		let resultError;
-		try {
-			return await Promise.resolve(result);
-		} catch (error) {
-			resultError = error;
-			throw error;
-		} finally {
+		const [{reason}] = await Promise.allSettled([promise]);
+		if (!cachePromiseRejection && reason) {
+			cache.delete(key);
+		} else if (maxAge) {
+			// Promise fulfilled, so start the timer
 			cache.set(key, {
-				data: result,
-				maxAge: maxAge ? Date.now() + maxAge : Number.POSITIVE_INFINITY
+				data: promise,
+				maxAge: Date.now() + maxAge
 			});
-
-			if (!cachePromiseRejection && resultError) {
-				cache.delete(key);
-			}
 		}
+
+		return promise;
 	};
 
 	mimicFn(memoized, fn);

test.js

@@ -10,6 +10,18 @@ test('main', async t => {
 	t.is(await memoized(10), 1);
 });
 
+test('does memoize consecutive calls', async t => {
+	let i = 0;
+	const memoized = pMemoize(async () => i++);
+	const firstCall = memoized();
+	const secondCall = memoized();
+
+	await Promise.all([firstCall, secondCall]);
+
+	t.is(await firstCall, 0);
+	t.is(await secondCall, 0);
+});
+
 test('does not memoize rejected promise', async t => {
 	let i = 0;