add download test back

.github/workflows/download_pipeline.yml

@@ -0,0 +1,119 @@
+name: Test successful pipeline download with 'nf-core pipelines download'
+
+# Run the workflow when:
+#  - dispatched manually
+#  - when a PR is opened or reopened to master branch
+#  - the head branch of the pull request is updated, i.e. if fixes for a release are pushed last minute to dev.
+on:
+  workflow_dispatch:
+    inputs:
+      testbranch:
+        description: "The specific branch you wish to utilize for the test execution of nf-core pipelines download."
+        required: true
+        default: "dev"
+  pull_request:
+    types:
+      - opened
+      - edited
+      - synchronize
+    branches:
+      - master
+  pull_request_target:
+    branches:
+      - master
+
+env:
+  NXF_ANSI_LOG: false
+
+jobs:
+  download:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Nextflow
+        uses: nf-core/setup-nextflow@v2
+
+      - name: Disk space cleanup
+        uses: jlumbroso/free-disk-space@54081f138730dfa15788a46383842cd2f914a1be # v1.3.1
+
+      - uses: actions/setup-python@82c7e631bb3cdc910f68e0081d67478d79c6982d # v5
+        with:
+          python-version: "3.12"
+          architecture: "x64"
+
+      - name: Setup Apptainer
+        uses: eWaterCycle/setup-apptainer@4bb22c52d4f63406c49e94c804632975787312b3 # v2.0.0
+        with:
+          apptainer-version: 1.3.4
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install git+https://github.com/nf-core/tools.git@dev
+
+      - name: Get the repository name and current branch set as environment variable
+        run: |
+          echo "REPO_LOWERCASE=${GITHUB_REPOSITORY,,}" >> ${GITHUB_ENV}
+          echo "REPOTITLE_LOWERCASE=$(basename ${GITHUB_REPOSITORY,,})" >> ${GITHUB_ENV}
+          echo "REPO_BRANCH=${{ github.event.inputs.testbranch || 'dev' }}" >> ${GITHUB_ENV}
+
+      - name: Make a cache directory for the container images
+        run: |
+          mkdir -p ./singularity_container_images
+
+      - name: Download the pipeline
+        env:
+          NXF_SINGULARITY_CACHEDIR: ./singularity_container_images
+        run: |
+          nf-core pipelines download ${{ env.REPO_LOWERCASE }} \
+          --revision ${{ env.REPO_BRANCH }} \
+          --outdir ./${{ env.REPOTITLE_LOWERCASE }} \
+          --compress "none" \
+          --container-system 'singularity' \
+          --container-library "quay.io" -l "docker.io" -l "community.wave.seqera.io" \
+          --container-cache-utilisation 'amend' \
+          --download-configuration 'yes'
+
+      - name: Inspect download
+        run: tree ./${{ env.REPOTITLE_LOWERCASE }}
+
+      - name: Count the downloaded number of container images
+        id: count_initial
+        run: |
+          image_count=$(ls -1 ./singularity_container_images | wc -l | xargs)
+          echo "Initial container image count: $image_count"
+          echo "IMAGE_COUNT_INITIAL=$image_count" >> ${GITHUB_ENV}
+
+      - name: Run the downloaded pipeline (stub)
+        id: stub_run_pipeline
+        continue-on-error: true
+        env:
+          NXF_SINGULARITY_CACHEDIR: ./singularity_container_images
+          NXF_SINGULARITY_HOME_MOUNT: true
+        run: nextflow run ./${{ env.REPOTITLE_LOWERCASE }}/$( sed 's/\W/_/g' <<< ${{ env.REPO_BRANCH }}) -stub -profile test,singularity --outdir ./results
+      - name: Run the downloaded pipeline (stub run not supported)
+        id: run_pipeline
+        if: ${{ job.steps.stub_run_pipeline.status == failure() }}
+        env:
+          NXF_SINGULARITY_CACHEDIR: ./singularity_container_images
+          NXF_SINGULARITY_HOME_MOUNT: true
+        run: nextflow run ./${{ env.REPOTITLE_LOWERCASE }}/$( sed 's/\W/_/g' <<< ${{ env.REPO_BRANCH }}) -profile test,singularity --outdir ./results
+
+      - name: Count the downloaded number of container images
+        id: count_afterwards
+        run: |
+          image_count=$(ls -1 ./singularity_container_images | wc -l | xargs)
+          echo "Post-pipeline run container image count: $image_count"
+          echo "IMAGE_COUNT_AFTER=$image_count" >> ${GITHUB_ENV}
+
+      - name: Compare container image counts
+        run: |
+          if [ "${{ env.IMAGE_COUNT_INITIAL }}" -ne "${{ env.IMAGE_COUNT_AFTER }}" ]; then
+            initial_count=${{ env.IMAGE_COUNT_INITIAL }}
+            final_count=${{ env.IMAGE_COUNT_AFTER }}
+            difference=$((final_count - initial_count))
+            echo "$difference additional container images were \n downloaded at runtime . The pipeline has no support for offline runs!"
+            tree ./singularity_container_images
+            exit 1
+          else
+            echo "The pipeline can be downloaded successfully!"
+          fi