generateForAnnotatedElement method

@override Future<String> generateForAnnotatedElement(Element element, ConstantReader annotation, BuildStep buildStep)

Implement to return source code to generate for element.

This method is invoked based on finding elements annotated with an instance of T. The annotation is provided as a ConstantReader.

Supported return values include a single String or multiple String instances within an Iterable or Stream. It is also valid to return a Future of String, Iterable, or Stream.

Implementations should return null when no content is generated. Empty or whitespace-only String instances are also ignored.

Implementation

@override
Future<String> generateForAnnotatedElement(
  Element element,
  ConstantReader annotation,
  BuildStep buildStep,
) async {
  final Element enviedEl = element;
  if (enviedEl is! ClassElement) {
    throw InvalidGenerationSourceError(
      '`@Envied` can only be used on classes.',
      element: enviedEl,
    );
  }

  final Envied config = Envied(
    path: _buildOptions.override == true &&
            _buildOptions.path?.isNotEmpty == true
        ? _buildOptions.path
        : annotation.read('path').literalValue as String?,
    requireEnvFile:
        annotation.read('requireEnvFile').literalValue as bool? ?? false,
    name: annotation.read('name').literalValue as String?,
    obfuscate: annotation.read('obfuscate').literalValue as bool,
    allowOptionalFields:
        annotation.read('allowOptionalFields').literalValue as bool? ?? false,
    useConstantCase:
        annotation.read('useConstantCase').literalValue as bool? ?? false,
    interpolate: annotation.read('interpolate').literalValue as bool? ?? true,
    rawStrings: annotation.read('rawStrings').literalValue as bool? ?? false,
  );

  final Map<String, EnvVal> envs =
      await loadEnvs(config.path, (String error) {
    if (config.requireEnvFile) {
      throw InvalidGenerationSourceError(
        error,
        element: enviedEl,
      );
    }
  });

  final DartEmitter emitter = DartEmitter(useNullSafetySyntax: true);

  final Class cls = Class(
    (ClassBuilder classBuilder) => classBuilder
      ..modifier = ClassModifier.final$
      ..name = '_${config.name ?? enviedEl.name}'
      ..fields.addAll([
        for (FieldElement field in enviedEl.fields)
          if (_typeChecker(EnviedField).hasAnnotationOf(field))
            ..._generateFields(
              field: field,
              config: config,
              envs: envs,
            ),
      ]),
  );

  const String ignore = '// coverage:ignore-file\n'
      '// ignore_for_file: type=lint';

  return DartFormatter().format('$ignore\n${cls.accept(emitter)}');
}