Cache implementation not working in github action - github

Question

I've tried to follow the official documentation, several blogs and answers on stackoverflow but nothing helped me to find a solution for this problem.
With github-action I've created a script to run unit tests after every push is done in our github server. For now the project is in early stage, so our dependency list is quite short and npm install command is done quite quickly (around 40 seconds). Obviously in future we'll need to add more dependencies and we are expecting a serious increment of that time, so I've tried to implement the cache mechanism, but for some reason the process still need to download the dependencies and the time for that step still be pretty much the same.
Below there is the script I've used. Following the documentation online I've found 2 different options, I've tried both (once per time) but without luck.
name: unit
on:
push:
branches: ['*']
pull_request:
branches: ['*']
workflow_dispatch:
jobs:
build:
runs-on: macos-latest
steps:
- uses: actions/checkout#v2
- name: setup node
uses: actions/setup-node#v2
with:
node-version: '15'
cache: npm
# start option 1
- name: Setup cache
uses: actions/cache#v2
with:
path: app/node_modules
key: ${{ runner.os }}-node-${{ hashFiles('app/package-lock.json') }}
restore-keys: |
${{ runner.os }}-node-
# end option 1
# start option 2
- name: Cache node modules
uses: actions/cache#v2
env:
cache-name: cache-node-modules
with:
path: ~/.npm
key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
restore-keys: |
${{ runner.os }}-build-${{ env.cache-name }}-
${{ runner.os }}-build-
${{ runner.os }}-
# end option 2
- name: Install dependencies
run: npm install
- name: run unit tests
run: npm run test
Why the cache is not working? Am I doing some mistake in the script?