fix(p-map-values): Keep order of entries in pMapValue

This method is used during the pack phase in pnpm.

As the key order is not guaranteed to be kept by it, the dependency order
may be changed as a result, leading to non-reproducible builds.

This fixes #208

Author: Tamas Kiss

p-map-values/__tests__/index.ts

@@ -3,3 +3,22 @@ import pMapValues from '../src'
 test('pMapValues', async () => {
   expect(await pMapValues(async (value: number) => value * 2, {a: 1, b: 2})).toEqual({a: 2, b: 4})
 })
+
+test('pMapValues - with symulated async work', async () => {
+  const delay = async (milliseconds: number) => {
+    return new Promise((resolve) => {
+      setTimeout(resolve, milliseconds)
+    });
+  }
+  const input = {a: 1, b: 2};
+
+  const mapped = await pMapValues(async (value: number) => {
+    await delay((2 - value) * 100);
+    return value * 2;
+  }, input);
+
+  const expected= {a: 2, b: 4};
+
+  expect(Object.keys(mapped)).toStrictEqual(Object.keys(expected));
+  expect(mapped).toStrictEqual(expected);
+})

p-map-values/src/index.ts

@@ -3,8 +3,11 @@ export default async function pMapValue<K extends string | number | symbol, V, U
   obj: Record<K, V>
 ): Promise<Record<K, U>> {
   const result: Record<K, U> = {} as Record<K, U>
+  const entries = Object.entries(obj) as [K, V][];
   await Promise.all(
-    Object.entries(obj).map(async ([key, value]: any) => { // eslint-disable-line @typescript-eslint/no-explicit-any
+    entries.map(async ([key, value]) => {
+      // initialize property in the resulting object to guarantee key order
+      result[key] = undefined as unknown as U;
       result[key] = await mapper(value, key, obj)
     })
   )