Added a test workflow (#309)

Co-authored-by: Valentin Seitz <[email protected]>
Co-authored-by: Gerasimos Chourdakis <[email protected]>

.github/workflows/system-tests.yaml

@@ -0,0 +1,29 @@
+name: System tests
+
+on:
+  pull_request:
+    types: [labeled]
+
+jobs:
+  gather-refs:
+    if: ${{ github.event.label.name == 'trigger-system-tests' }}
+    runs-on: ubuntu-latest
+    outputs:
+      reftutorials: ${{ steps.reftutorials.outputs.shorthash }}
+    steps:
+      - id: reftutorials
+        uses: nmbgeek/github-action-get-latest-commit@main
+        with:
+          owner: precice
+          repo: tutorials
+          branch: develop
+
+  run-system-tests:
+    if: ${{ github.event.label.name == 'trigger-system-tests' }}
+    needs: gather-refs
+    uses: precice/tutorials/.github/workflows/run_testsuite_workflow.yml@develop
+    with:
+      suites: openfoam_adapter_pr
+      build_args: TUTORIALS_REF:${{ needs.gather-refs.outputs.reftutorials }},PRECICE_REF:v3.0.0,OPENFOAM_EXECUTABLE:openfoam2306,OPENFOAM_ADAPTER_REF:${{ github.event.pull_request.head.sha }}
+      systests_branch: develop
+      loglevel: "DEBUG"

CONTRIBUTING.md

@@ -27,3 +27,13 @@ There are also a few additional workflows that can be triggered manually:
 - `Check links`: checks the links in all markdown files to verify if they are still reachable.
 
 Members of the repository can trigger these workflows in the "Actions" tab.
+
+## System tests
+
+For non-trivial pull requests, we also need to execute [system regression tests](https://precice.org/dev-docs-system-tests.html),
+to ensure that complete simulations still run and give the same results.
+Because these take long, run on an external system, and consume significant resources,
+we are only triggering these on demand. Add (or ask a maintainer to add) the
+`trigger-system-tests` label to the pull request to trigger them.
+The tests will only run once, so that further commits don't consume additional
+resources: In case you want to re-trigger them, remove and add the label again.