Some examples for how to build dart code from another dart code using package:analyzer and package:code_builder only (i.e. no build_runner or build.yaml files).

In the example folder, there are three different stand-alone examples. Each one of them can be simply executed as follow:

[~/path/to/repo] dart run example/<file_name>.dart

• ast_example
  • Shows how an Abstract Syntax Tree (AST) can be generated from a source code using package:analyzer.
  • How to visit elements in the tree.

• code_builder
  • Shows how to build code programmatically using package:code_builder

• data_class_builder_example

  • combines both examples to generate a data class.

  • In short, it takes this as an input:

  class Person { final String name; final String? nickname; final int age; final double height; final List<String> hobbies; }

  • To generate this as an output:
    
    

  class Person { const Person({ required this.name, this.nickname, required this.age, required this.height, required this.hobbies, }); factory Person.fromMap(Map<String, dynamic> map) { return Person( name: map['name'], nickname: map['nickname'], age: map['age'].toInt(), height: map['height'].toDouble(), hobbies: List.from(map['hobbies']), ); } factory Person.fromJson(String source) => Person.fromMap(json.decode(source)); final String name; final String? nickname; final int age; final double height; final List<String> hobbies; Person copyWith({ String? name, String? nickname, int? age, double? height, List<String>? hobbies, }) { return Person( name: name ?? this.name, nickname: nickname ?? this.nickname, age: age ?? this.age, height: height ?? this.height, hobbies: hobbies ?? this.hobbies, ); } String toJson() => json.encode(toMap()); Map<String, dynamic> toMap() { return { 'name': name, 'nickname': nickname, 'age': age, 'height': height, 'hobbies': hobbies, }; } @override String toString() { return 'Person(name: $name, nickname: $nickname, age: $age, height: $height, hobbies: $hobbies)'; } @override bool operator ==(Object other) { if (identical(this, other)) return true; // TODO: handle list equality here return other is Person && other.name == name && other.nickname == nickname && other.age == age && other.height == height && other.hobbies == hobbies; } @override int get hashCode { return name.hashCode ^ nickname.hashCode ^ age.hashCode ^ height.hashCode ^ hobbies.hashCode; } } 

Disclimar: These examples were written (poorly) for learning purposes and to understand how these packages work together -- no more no less.