Issue in caching dependencies in github actions - npm

Question

I am trying to use the shard option in jest to run my tests in parallel across multiple runners.
But before I can do this on CI - I have to do some other steps like checkout codebase, install dependencies in the specific job running the test.
Problem statement - I want to avoid installing dependencies for each shard of test running.
I searched around the internet and found that I cannot do this in another preceding job because each job starts fresh in its own container.
Hence I wrote something like this:
run_tests:
runs-on: [self-hosted]
name: Run Tests
continue-on-error: false
strategy:
matrix:
shard: [1, 2, 3, 4]
steps:
- name: Checkout Codebase
uses: actions/checkout-action#v2
- name: Use Node v14.15.1
uses: actions/setup-node#v1
with:
node-version: 14.15.1
- name: Cache NPM dependencies
id: npmCacheStep
uses: actions/cache#v2
with:
path: ~/.npm
key: ${{ runner.OS }}-npm-cache-${{ hashFiles('**/package-lock.json') }}
restore-keys: |
${{ runner.OS }}-npm-cache-
- name: Install Dependencies
if: steps.npmCacheStep.outputs.cache-hit != 'true'
run: npm ci
- name: Run tests
run: npm run test -- --colors --coverage --shard=${{ matrix.shard }}/${{ strategy.job-total }}
To solve my problem statement, I'm saying that if it found a cache of npm dependencies - then don't install npm modules again as recommended at lots of places - https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows
But when I try to run this
the npm install step is skipped (as expected)
I get the following error on github actions workflow logs:
I am trying this solution: Is there a way to speedup npm ci using cache?