test-pull-request-java.yml

name: Smoke Test Pull Request (Java)

on:
  merge_group:
  pull_request:
    branches:
      - main
    paths:
      - 'java/**'

jobs:
  prepare:
    name: Prepare
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.paths.outputs.matrix }}
    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - name: Discover changed paths
        id: paths
        run: |
          set -eo pipefail
          # 1st step: we get the list of files changed between the tip of this PR branch and main
          # Since we're only interested in the folders containing those files, we get them, sort them alphabetically (`sort`), de duplicate them (`uniq`) and filter out dot folders (.github for example)
          # we end up with, for example, changed_java_folders="java/akka/smoke_test\njava/kotlin/gradle/wrapper\njava/application-insights"
          changed_java_folders=$(  git diff --name-only --merge-base origin/$GITHUB_BASE_REF $GITHUB_SHA  | xargs -n 1 dirname | sort -k 2 | uniq | grep -v "^\." )
          
          # 2nd step: we only want to keep the folders that contain a `smoke_test` subfolder -> those contain the tests we can run
          # To do that, we loop through all the changed_java_folders and test (`-s`) for a sub folder named `smoke_test`; if there's none, we go to the parent directory (`dirname`)
          # eventually, we'll find a `smoke_test` folder and add it to `smoke_test_folders`; if not, we move on to the next changed_java_folders entry (until the `.` folder in which case we give up)
          
          smoke_test_folders=""
          while read -r changed_folder
          do
            echo "working on $changed_folder"
            smoke_test=""
            current_folder=$changed_folder
            while [ -z "$smoke_test" ] && [ "$current_folder" != "." ]
            do
              echo "--smoke_test is $smoke_test"
              echo "--current_folder is $current_folder"
              if [[ -s $current_folder/smoke_test ]]; then
                smoke_test="$current_folder/smoke_test"
              else
                current_folder=$(dirname $current_folder)
              fi
            done
            if [ "$current_folder" != "." ]; then
              smoke_test_folders="$smoke_test_folders\"$smoke_test\"\n"
            fi
          done <<<"$changed_java_folders"

          # Once the smoke_test_folders are all found, we de duplicate them (`uniq`), remove extra empty lines (`\S`), and format them into a string
          # we end up with, for example, smoke_test_folders='"java/akka/smoke_test","java/kotlin/smoke_test","java/application-insights/smoke_test"'
          # see: https://stackoverflow.com/a/8721550/24069 for usage of paste
          smoke_test_folders=$( echo -e $smoke_test_folders | uniq  | grep "\S" | paste -s -d, -)

          echo "These are the Java folders where we found changes for this PR : $changed_java_folders" >> $GITHUB_STEP_SUMMARY
          echo "These are the Java folders where we found changes AND the presence of smoke tests for this PR : $smoke_test_folders" >> $GITHUB_STEP_SUMMARY
          echo "matrix={\"java_sample_folder\":[$smoke_test_folders]}" >> $GITHUB_OUTPUT
          echo "This is how the matrix will look like: $(cat $GITHUB_OUTPUT)"

  smoke:
    needs: prepare
    name: Smoke Tests
    runs-on: ubuntu-latest
    strategy:
      matrix: ${{ fromJSON(needs.prepare.outputs.matrix) }}

    steps:
      - name: Setup Go
        uses: actions/setup-go@v5
        with:
          go-version: 1.22.x

      - name: Checkout
        uses: actions/checkout@v4

      - name: Smoke Test Java samples
        run: |
          echo "About to run the smoke test script against this suite folder: ${{ matrix.java_sample_folder }}/smoke_test"
          ./scripts/smoke.sh --suite ${{ matrix.java_sample_folder }} \
                             --builder paketobuildpacks/builder-jammy-tiny:latest