.github/workflows/flutter-prep.yaml

# Copyright 2023 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

name: Flutter SDK prep

on:
  workflow_call:
    inputs:
      os-name:
        description: 'The OS to run against, either "macos" or "ubuntu". If neither is provided, will run against both.'
        type: string
      needs-checkout-merge:
        description: "Whether the PR should be merged during the checkout step. Necessary for pull_request_target workflows."
        type: boolean
      requires-label:
        description: "Specifies the label required for the workflow to run. If not provided, the workflow will always run."
        type: string

    outputs:
      latest_flutter_candidate:
        description: "The latest Flutter candidate version."
        value: ${{ jobs.reusable-flutter-prep.outputs.latest_flutter_candidate }}

jobs:
  reusable-flutter-prep:
    # Note: Do not delete the following check. This is needed for the DCM workflow.
    if: inputs.requires-label == '' || contains(github.event.pull_request.labels.*.name, inputs.requires-label)
    name: ${{ matrix.os }} Flutter Prep
    outputs:
      latest_flutter_candidate: ${{ steps.flutter-candidate.outputs.FLUTTER_CANDIDATE }}
    strategy:
      matrix:
        os: ${{ (inputs.os-name == 'macos' && fromJSON('[ "macos-latest"]')) || (inputs.os-name == 'ubuntu' && fromJSON('[ "ubuntu-latest"]')) || fromJSON('["ubuntu-latest", "macos-latest"]') }}
    runs-on: ${{ matrix.os }}
    steps:
      # TODO(https://github.com/flutter/devtools/issues/5729) Consider caching DevTools so that we
      # don't check it out again is subsequent workflows.

      # Merge in the PR branch during checkout using the PR's sha. This is necessary for pull_request_target
      # workflows. See: https://github.com/actions/checkout/issues/518
      - name: Checkout PR branch for DevTools
        if: ${{ inputs.needs-checkout-merge == true }}
        id: checkout-pr-branch
        uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9
        with:
          ref: "${{ github.event.pull_request.head.sha }}"

      # Otherwise use the default checkout action.
      - name: Checkout DevTools (default)
        if: steps.checkout-pr-branch.outcome == 'skipped'
        uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9

      - name: Get Latest Flutter Candidate
        id: flutter-candidate
        run: |
          LATEST_FLUTTER_CANDIDATE=$(./tool/latest_flutter_candidate.sh)
          echo "FLUTTER_CANDIDATE=$LATEST_FLUTTER_CANDIDATE" >> $GITHUB_OUTPUT

      - name: Load Cached Flutter SDK
        id: cache-flutter
        uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8
        with:
          path: |
            ./flutter-sdk
          key: flutter-sdk-${{ runner.os }}-${{ steps.flutter-candidate.outputs.FLUTTER_CANDIDATE }}

      - if: ${{ steps.cache-flutter.outputs.cache-hit != 'true' }}
        name: Clone Flutter SDK if none cached
        run: |
          git clone https://github.com/flutter/flutter.git ./flutter-sdk
          cd flutter-sdk
          git checkout $LATEST_FLUTTER_CANDIDATE
        env:
          LATEST_FLUTTER_CANDIDATE: ${{ steps.flutter-candidate.outputs.FLUTTER_CANDIDATE }}

      - name: Assert that the Latest Flutter Candidate is checked out
        run: |
          cd flutter-sdk
          HEAD_SHA=$(git rev-parse HEAD)
          LATEST_FLUTTER_CANDIDATE_SHA=$(git rev-list -1 "$LATEST_FLUTTER_CANDIDATE")
          if [ "$HEAD_SHA" != "$LATEST_FLUTTER_CANDIDATE_SHA" ]; then
            echo "::error ,title=Error checking out Latest Flutter Candidate::{expected HEAD to be at $LATEST_FLUTTER_CANDIDATE_SHA but got $HEAD_SHA}"
            exit 1
          fi
        env:
          LATEST_FLUTTER_CANDIDATE: ${{ steps.flutter-candidate.outputs.FLUTTER_CANDIDATE }}

      - name: Setup Flutter SDK
        run: |
          ./flutter-sdk/bin/flutter config --no-analytics
          ./flutter-sdk/bin/flutter doctor
          ./flutter-sdk/bin/cache/dart-sdk/bin/dart --disable-analytics