feat: workspace matrix command for detecting affected projects based on diff

[IchordeDionysos]

Status

READY

Description

solves #1695.

Makes it easier to runs tests in large app projects, by allowing to discover changes projects and selectively run those projects tests.

very_good workspace matrix --base origin/main

returns a list of affected project, which can be handed to a GitHub Action matrix, for only running those projects tests.

This is how an example GitHub Action workflow could look like:

GitHub Action - very_good_cli Test Matrix

name: CI

on:
  pull_request:
    branches: [main]
  push:
    branches: [main]

jobs:
  detect-affected:
    runs-on: ubuntu-latest
    outputs:
      matrix: ${{ steps.affected.outputs.matrix }}
      has_affected: ${{ steps.affected.outputs.has_affected }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0 # Requires full history to diff against target branch

      - uses: subosito/flutter-action@v2
        with:
          channel: 'stable'

      - name: Install Very Good CLI
        run: dart pub global activate very_good_cli

      - name: Detect Affected Workspace Packages
        id: affected
        run: |
          # Hypothetical CLI command: inspects Git diff against target branch,
          # maps workspace dependencies, and outputs JSON array of targets:
          # [{"name": "core_library_2", "path": "packages/core/core_library_2"}, ...]
          MATRIX_JSON=$(very_good workspace matrix --base origin/${{ github.base_ref || 'main' }})
          
          echo "matrix=$MATRIX_JSON" >> $GITHUB_OUTPUT
          
          if [ "$MATRIX_JSON" = "[]" ]; then
            echo "has_affected=false" >> $GITHUB_OUTPUT
          else
            echo "has_affected=true" >> $GITHUB_OUTPUT
          fi

  test:
    needs: detect-affected
    if: ${{ needs.detect-affected.outputs.has_affected == 'true' }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false # Allows all matrix jobs to complete so developers see all failures
      matrix:
        package: ${{ fromJson(needs.detect-affected.outputs.matrix) }}

    steps:
      - uses: actions/checkout@v4

      - uses: subosito/flutter-action@v2
        with:
          channel: 'stable'

      - name: Install Very Good CLI
        run: dart pub global activate very_good_cli

      - name: unit tests - ${{ matrix.package.name }}
        working-directory: ${{ matrix.package.path }}
        run: |
          very_good test --coverage

      - name: Upload Coverage to Codecov
        uses: codecov/codecov-action@v4
        working-directory: ${{ matrix.package.path }}
        with:
          files: ${{ matrix.package.path }}/coverage/lcov.info
          flags: ${{ matrix.package.name }} # Essential for Codecov Carryforward Flags
          token: ${{ secrets.CODECOV_TOKEN }}

  ci-status:
    name: unit tests
    needs: [detect-affected, test]
    if: always()
    runs-on: ubuntu-latest
    steps:
      - name: Evaluate Aggregate Matrix Status
        run: |
          if [ "${{ needs.test.result }}" == "failure" ] || [ "${{ needs.detect-affected.result }}" == "failure" ]; then
            echo "One or more package checks failed."
            exit 1
          fi
          echo "All affected package tests passed successfully!"

Type of Change

• ✨ New feature (non-breaking change which adds functionality)
• 🛠️ Bug fix (non-breaking change which fixes an issue)
• ❌ Breaking change (fix or feature that would cause existing functionality to change)
• 🧹 Code refactor
• ✅ Build configuration change
• 📝 Documentation
• 🗑️ Chore