Implement automatic sharding for nf-test (#1810)

closes #1811 

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## PR checklist

- [ ] This comment contains a description of changes (with reason).
- [ ] If you've fixed a bug or added code that should be tested, add
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.github/actions/get-shards/action.yml

@@ -0,0 +1,66 @@
+name: "Get number of shards"
+description: "Get the number of nf-test shards for the current CI job"
+inputs:
+  max_shards:
+    description: "Maximum number of shards allowed"
+    required: true
+  paths:
+    description: "Component paths to test"
+    required: false
+outputs:
+  shard:
+    description: "Array of shard numbers"
+    value: ${{ steps.shards.outputs.shard }}
+  total_shards:
+    description: "Total number of shards"
+    value: ${{ steps.shards.outputs.total_shards }}
+runs:
+  using: "composite"
+  steps:
+    - name: Install nf-test
+      uses: nf-core/setup-nf-test@v1
+      with:
+        version: ${{ env.NFT_VER }}
+    - name: Get number of shards
+      id: shards
+      shell: bash
+      run: |
+        # Run nf-test with dynamic parameter
+        nftest_output=$(nf-test test \
+          --dry-run \
+          --profile +docker \
+          --filter function,workflow,pipeline \
+          --ci \
+          --changed-since HEAD^) || {
+            echo "nf-test command failed with exit code $?"
+            echo "Full output: $nftest_output"
+            exit 1
+        }
+        echo "nf-test dry-run output: $nftest_output"
+
+        # Default values for shard and total_shards
+        shard="[]"
+        total_shards=0
+
+        # Check if there are related tests
+        if echo "$nftest_output" | grep -q 'No tests to execute'; then
+          echo "No related tests found."
+        else
+          # Extract the number of related tests
+          number_of_shards=$(echo "$nftest_output" | sed -n 's|.*Executed \([0-9]*\) tests.*|\1|p')
+          if [[ -n "$number_of_shards" && "$number_of_shards" -gt 0 ]]; then
+            shards_to_run=$(( $number_of_shards < ${{ inputs.max_shards }} ? $number_of_shards : ${{ inputs.max_shards }} ))
+            shard=$(seq 1 "$shards_to_run" | jq -R . | jq -c -s .)
+            total_shards="$shards_to_run"
+          else
+            echo "Unexpected output format. Falling back to default values."
+          fi
+        fi
+
+        # Write to GitHub Actions outputs
+        echo "shard=$shard" >> $GITHUB_OUTPUT
+        echo "total_shards=$total_shards" >> $GITHUB_OUTPUT
+
+        # Debugging output
+        echo "Final shard array: $shard"
+        echo "Total number of shards: $total_shards"

.github/actions/nf-test/action.yml

@@ -0,0 +1,124 @@
+name: "nf-test Action"
+description: "Runs nf-test with common setup steps"
+inputs:
+  profile:
+    description: "Profile to use"
+    required: true
+  shard:
+    description: "Shard number for this CI job"
+    required: true
+  total_shards:
+    description: "Total number of test shards(NOT the total number of matrix jobs)"
+    required: true
+  paths:
+    description: "Test paths"
+    required: true
+
+runs:
+  using: "composite"
+  steps:
+    - name: Setup Nextflow
+      uses: nf-core/setup-nextflow@v2
+      with:
+        version: "${{ env.NXF_VERSION }}"
+
+    - name: Set up Python
+      uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5
+      with:
+        python-version: "3.11"
+
+    - name: Install nf-test
+      uses: nf-core/setup-nf-test@v1
+      with:
+        version: "${{ env.NFT_VER }}"
+
+    - name: Setup apptainer
+      if: contains(inputs.profile, 'singularity')
+      uses: eWaterCycle/setup-apptainer@main
+
+    - name: Set up Singularity
+      if: contains(inputs.profile, 'singularity')
+      shell: bash
+      run: |
+        mkdir -p $NXF_SINGULARITY_CACHEDIR
+        mkdir -p $NXF_SINGULARITY_LIBRARYDIR
+
+    - name: Conda setup
+      if: ${{inputs.profile == 'conda'}}
+      uses: conda-incubator/setup-miniconda@505e6394dae86d6a5c7fbb6e3fb8938e3e863830 # v3
+      with:
+        auto-update-conda: true
+        conda-solver: libmamba
+        conda-remove-defaults: true
+
+    # Set up secrets
+    - name: Set up nextflow secrets
+      if: env.SENTIEON_ENCRYPTION_KEY != '' && env.SENTIEON_LICENSE_MESSAGE != ''
+      shell: bash
+      run: |
+        python -m pip install cryptography
+        nextflow secrets set SENTIEON_AUTH_DATA $(python3 tests/modules/nf-core/sentieon/license_message.py encrypt --key "$SENTIEON_ENCRYPTION_KEY" --message "$SENTIEON_LICENSE_MESSAGE")
+
+    - name: Install pdiff
+      shell: bash
+      run: |
+        python -m pip install pdiff
+
+      # TODO Skip failing conda tests and document their failures
+      # https://github.com/nf-core/modules/issues/7017
+    - name: Run nf-test
+      shell: bash
+      env:
+        NFT_DIFF: ${{ env.NFT_DIFF }}
+        NFT_DIFF_ARGS: ${{ env.NFT_DIFF_ARGS }}
+        NFT_WORKDIR: ${{ env.NFT_WORKDIR }}
+        SENTIEON_AUTH_MECH: "GitHub Actions - token"
+        SENTIEON_LICSRVR_IP: ${{ env.SENTIEON_LICSRVR_IP }}
+      run: |
+        nf-test test \
+          --profile=+${{ inputs.profile }} \
+          --tap=test.tap \
+          --verbose \
+          --ci \
+          --shard ${{ inputs.shard }}/${{ inputs.total_shards }} \
+          --filter function,workflow,pipeline
+
+          # Save the absolute path of the test.tap file to the output
+          echo "tap_file_path=$(realpath test.tap)" >> $GITHUB_OUTPUT
+
+    - name: Generate test summary
+      if: always()
+      shell: bash
+      run: |
+        # Add header if it doesn't exist (using a token file to track this)
+        if [ ! -f ".summary_header" ]; then
+          echo "# 🚀 nf-test results" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "| Status | Test Name | Profile | Shard |" >> $GITHUB_STEP_SUMMARY
+          echo "|:------:|-----------|---------|-------|" >> $GITHUB_STEP_SUMMARY
+          touch .summary_header
+        fi
+
+        if [ -f test.tap ]; then
+          while IFS= read -r line; do
+            if [[ $line =~ ^ok ]]; then
+              test_name="${line#ok }"
+              # Remove the test number from the beginning
+              test_name="${test_name#* }"
+              echo "| ✅ | ${test_name} | ${{ inputs.profile }} | ${{ inputs.shard }}/${{ inputs.total_shards }} |" >> $GITHUB_STEP_SUMMARY
+            elif [[ $line =~ ^not\ ok ]]; then
+              test_name="${line#not ok }"
+              # Remove the test number from the beginning
+              test_name="${test_name#* }"
+              echo "| ❌ | ${test_name} | ${{ inputs.profile }} | ${{ inputs.shard }}/${{ inputs.total_shards }} |" >> $GITHUB_STEP_SUMMARY
+            fi
+          done < test.tap
+        else
+          echo "| ⚠️ | No test results found | ${{ inputs.profile }} | ${{ inputs.shard }}/${{ inputs.total_shards }} |" >> $GITHUB_STEP_SUMMARY
+        fi
+
+    - name: Clean up
+      if: always()
+      shell: bash
+      run: |
+        sudo rm -rf /home/ubuntu/tests/