Github Action: run one step before matrix combinations - github

Question

I'm creating a Github Action Workflow.
There is a phing build file that creates multiple zips depending on product variations. This is done with a matrix.
Before the product is build there is a JS File that needs to be build. That's done with a rollup build file.
Everything works fine, but the JS build only needs to be done once and not with every matrix combination.
I don't know how that should be done. Maybe with a single separate workflow running at start, but how would the finished JS file be pushed into the next workflow? Or maybe one workflow is fine?
name: Build
on: [push]
jobs:
build:
runs-on: ubuntu-latest
env:
VERSION: 1.0.1
strategy:
matrix:
edition: ["product1", "product2", "product3"]
limits: [100, 200, 300]
exclude:
- edition: product1
limits: 100
- edition: product2
limits: 100
- edition: product1
limits: 200
- edition: product2
limits: 200
steps:
- uses: actions/checkout#v2
- name: Build JS
uses: actions/setup-node#v1
with:
node-version: 12.x
- name: Cache Node.js modules
uses: actions/cache#v2
with:
path: ~/.npm
key: ${{ runner.OS }}-node-${{ hashFiles('**/package-lock.json') }}
restore-keys: |
${{ runner.OS }}-node-
${{ runner.OS }}-
- run: npm ci
- run: npm run build # builds main.js
- name: Phing Build
uses: phingofficial/phing-github-action#main
with:
repo-token: "${{ secrets.GITHUB_TOKEN }}"
buildfile: build/phing/build.xml
targets: main
user-properties: editions=${{ matrix.edition }} limits=${{ matrix.limits }}
version: 3.0.0-alpha4
- name: Archive code
uses: actions/upload-artifact#v2
with:
name: file-${{ matrix.edition }}${{ matrix.limits }}-v${{ env.VERSION }}
path: build/${{ matrix.edition }}/zip/
retention-days: 1

Answer 1

You can execute creating the JS File in a separate job (let's name it prepare) and then reference that job in the job with the matrix definition (build) using the needs keyword. Sharing files across jobs is something that GitHub is very specific about: not each job needs all files from a previous job, so you will need to upload and download that file yourself.
Example setup:
jobs:
prepare:
runs-on: ubuntu-latest
steps:
...
# upload the file here for later use
- uses: actions/upload-artifact
build:
needs: prepare
strategy:
matrix:
edition: ["product1", "product2", "product3"]
steps:
# download the file here so you can use it
- uses: actions/download-artifact
See the docs on the needs keyword here.