feat: advanced custom script definitions (with package selection prompting)

[Salakar]

---

Goal: Improve local developer experience when running scripts and to make scripts in a repository more 'new contributor' friendly (don't need to remember what each script does and can easily target specific packages now).

---

Example melos.yaml from FlutterFire:

name: FlutterFire

packages:
  - packages/**

scripts:
  analyze:
    run: |
      melos exec -c 5 --fail-fast -- \
        dart analyze .
    description: |
      Run `dart analyze` in all packages.
       - Note: you can also rely on your IDEs Dart Analysis / Issues window.

  format:
    run: dart pub global run flutter_plugin_tools format
    description: |
      Build a specific example app for Android.
       - Requires `flutter_plugin_tools` (`pub global activate flutter_plugin_tools`).
       - Requires `clang-format` (can be installed via Brew on macOS).

  build:example_android:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter build apk --no-pub"
    description: Build a specific example app for Android.
    select-package:
      dir-exists:
        - android
      scope: '*example*'

  build:example_ios:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter build ios --no-codesign --no-pub"
    description: Build a specific example app for iOS.
    select-package:
      dir-exists:
        - ios
      scope: '*example*'

  build:example_macos:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter build macos --no-pub"
    description: |
      Build a specific example app for macOS.
       - Requires `flutter channel master`.
       - Requires `flutter config --enable-macos-desktop` set.
    select-package:
      dir-exists:
        - macos
      scope: '*example*'

  test:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter test --no-pub"
    description: Run `flutter test` for a specific package.
    select-package:
      dir-exists:
        - test
      ignore:
        - '*web*'
        - '*example*'

  test:web:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter test --no-pub --platform=chrome"
    description: Run `flutter test --platform=chrome` for a specific '*web' package.
    select-package:
      dir-exists:
        - test
      scope: '*web*'

  test:mobile_e2e:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter drive --no-pub --target=./test_driver/MELOS_PARENT_PACKAGE_NAME_e2e.dart"
    description: |
      Run all Android or iOS test driver e2e tests in a specific example app.
       - Requires an Android emulator or iOS simulator.
    select-package:
      dir-exists:
        - test_driver
      scope: '*example*'

  test:web_e2e:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter drive -d web --no-pub --target=./test_driver/MELOS_PARENT_PACKAGE_NAME_e2e.dart"
    description: |
      Run all Web test driver e2e tests in a specific example app.
       - Requires `flutter channel master` (or beta).
       - Requires `flutter config --enable-web` set.
       - Requires chromedriver running on port 4444.
    select-package:
      dir-exists:
        - web
        - test_driver
      scope: '*example*'

  test:macos_e2e:
    run: |
      melos exec -c 1 --fail-fast -- \
        "flutter drive -d macos --no-pub --target=./test_driver/MELOS_PARENT_PACKAGE_NAME_e2e.dart"
    description: |
      Run all MacOS test driver e2e tests in a specific example app.
       - Requires `flutter channel master`.
       - Requires `flutter config --enable-macos-desktop` set.
    select-package:
      dir-exists:
        - macos
        - test_driver
      scope: '*example*'

  # Additional cleanup lifecycle script, executed when `melos clean` is ran.
  postclean: >
    melos exec -c 5 -- "flutter clean"

dev_dependencies:
  pedantic: 1.8.0

environment:
  sdk: ">=2.1.0 <3.0.0"
  flutter: ">=1.12.13+hotfix.5 <2.0.0"

melos run output: