Understanding npm packages inside github actions - github

Question

Here is my idea: build a static web page template, over time add .md files to a /posts directory and build a CI job to convert the .md files to html (with the showdownjs/showdown package).
Is there a need to install the package on every push? Seems like a waste, but uploading /node-modules is incorrect as well. Is there a way to install the package once, and let github action just work with it (run the md to html converter on newly added files)?

Answer 1

You have 2 options:
Recommened: Use caching action to cache dependencies for your project - using a hash from package-lock.json as a key to make sure it rebuild when depenendencies has changed:
- name: Cache node modules
uses: actions/cache#v2
env:
cache-name: cache-node-modules
with:
# npm cache files are stored in `~/.npm` on Linux/macOS
path: ~/.npm
key: ${{ hashFiles('**/package-lock.json') }}
- name: Install Dependencies
run: npm install
Push your node_modules to Git repository so it's checkout together with everything else
For optimising a need to run your converted you can use this action:
https://github.com/tj-actions/changed-files/
and detect if any files were modified at certain path