As a developer I want to specify the output of the generated file in the configuration. So

gator -c colors.yaml -o example/my_colors.dart

Turns into

gator:
  output: example/my_colors.dart
  class: MyColors
  colors:
    royalBlue: '0xff062091'
    grey: '#d6d6d6'
    rebeccaPurple: '663399'

As a developer, when creating a pull request, I want all tests to run to ensure I have not "broken" anything that I did not anticipate.

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I want to mark a color with an alias

gator:
  class: ExampleColors
  output: lib/src/colors.g.dart
  colors:
    Pale Spring Bud: 
      hex: 'dce2aa'
      alias: primary

  /// Primary App Color:
  /// **Pale Spring Bud**
  static const MaterialColor primary = paleSpringBud;

  static const _paleSpringBudPrimaryValue = 0xffdce2aa;

  /// **Pale Spring Bud**
  /// {@macro gator_header}
  static const paleSpringBud = MaterialColor(
    _paleSpringBudPrimaryValue,
    <int, Color>{
      050: Color(0xffeaeecc),
      100: Color(0xffe7ebc4),
      200: Color(0xffe3e8bb),
      300: Color(0xffe0e5b3),
      400: Color(0xffdce2aa),
      500: Color(_paleSpringBudPrimaryValue),
      600: Color(0xffc6cb99),
      700: Color(0xffb0b588),
      800: Color(0xff9a9e77),
      900: Color(0xff848866),
    },
  );

As a user I would like to know why the gator executable is not working for any of the conditions:

• no input YAML document found, for example: pubspec.yaml, some/path/config_colors.yaml, etc.
• cannot write to the output given
• a configuration is incorrect
• If a file already exists, prompt for overwrite