How to cache firebase/emulators directory using GitHub Actions - github-actions

Question

I am using the firebase emulator to run my tests and, I received a warning about a chance of optimization using the cache system.
How I can do this?
It appears you are running in a CI environment. You can avoid downloading the Firestore Emulator repeatedly by caching the /home/runner/.cache/firebase/emulators directory.

Answer 1

Define this in GitHub Actions:
steps:
- uses: actions/checkout#v2
- name: Cache firebase emulators
uses: actions/cache#v2
with:
path: ~/.cache/firebase/emulators
key: ${{ runner.os }}-firebase-emulators-${{ hashFiles('~/.cache/firebase/emulators/**') }}
...
Then, for example, when we run this command firebase emulators:exec --project example 'npm test', if the emulator is not in the cache path, it will automatically start installing.
First run
Cache is missing
Download emulator when running test
Save cache as post action of actions/cache
Second run
Cache is found and restored and download doesn't happen.

Answer 2

If you need to update tool when npm package updates use something like this:
- name: Get Library Versions For Binary Caching
id: cache-settings
run: |
echo "::set-output name=firebase-tools::$(yarn list -s --depth=0 --pattern firebase-tools | tail -n 1 | sed 's/.*#//g')"
echo "::set-output name=firebase-tools::$(npm list -s --depth=0 | grep firebase-tools | tail -n 1 | sed 's/.*#//g')"
- name: Cache Firebase Emulator Binaries
uses: actions/cache#v2.1.2
with:
path: ~/.cache/firebase/emulators
key: ${{ runner.os }}-firebase-${{ steps.cache-settings.outputs.firebase-tools }}

Answer 3

According to documentation:
https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows
inside your .github/workflows/filename.yml include cache instructions:
on: [push, pull_request]
jobs:
emulator_test:
name: Run all tests using Firebase Emulator
runs-on: ubuntu-latest
steps:
...
# other instructions
...
- name: Cache node modules
id: cache-npm
uses: actions/cache#v3
env:
cache-name: cache-node-modules
with:
# npm cache files are stored in `~/.npm` on Linux/macOS
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 }}-
- if: ${{ steps.cache-npm.outputs.cache-hit != 'true' }}
name: List the state of node modules
continue-on-error: true
run: npm list
- name: Cache firebase emulators
uses: actions/cache#v2
with:
path: ~/.cache/firebase/emulators
key: ${{ runner.os }}-firebase-${{ steps.cache-npm.outputs.firebase-tools }}
...
# other instructions
...
Without cache instructions:
Using cache instructions.