Dart Macros x Firestore

firebase_model_macro.dart

import 'dart:async';
import 'package:macros/macros.dart';

macro class FirestoreModel implements ClassDeclarationsMacro {
  const FirestoreModel(this.collectionPath);

  final String collectionPath;

  @override
  FutureOr<void> buildDeclarationsForClass(ClassDeclaration clazz, MemberDeclarationBuilder builder) async {
    final firestore = Uri.parse('package:cloud_firestore/cloud_firestore.dart');

    builder.declareInLibrary(
      DeclarationCode.fromParts([
        'import \'${firestore.toString()}\';',
      ]),
    );

    final className = clazz.identifier.name;
    final fields = await builder.fieldsOf(clazz);
    builder.debugPrint("className: $className");
    builder.debugPrint("fields: ${fields.map((f) => f.identifier.name).join(', ')}");

    builder.declareInType(
      DeclarationCode.fromParts(
        [
          '''
  static CollectionReference<$className> collectionRef() => FirebaseFirestore.instance.collection('$collectionPath').withConverter(
      fromFirestore: (snapshot, options) {
        final data = snapshot.data()!;
        data['id'] = snapshot.id;
        return User.fromJson(data);
      },
      toFirestore: (user, options) {
        return user.toJson();
      },
    );
''',
          '''
  static DocumentReference<$className> docRef(String id) => collectionRef().doc(id);
''',
        ],
      ),
    );

  }
}

extension MemberDeclarationBuilderEx on MemberDeclarationBuilder {
  void debugPrint(String message) {
    declareInLibrary(
      DeclarationCode.fromParts([
        '// $message',
      ]),
    );
  }
}

user.dart

@JsonCodable()
@FirestoreModel('users')
class User {
  final String id;
  final String name;
  final int age;

  User({
    required this.id,
    required this.name,
    required this.age,
  });
}

user_augment.dart

part of 'package:flutter_firebase_macros/user.dart';

import 'dart:core' as prefix0;

import 'package:cloud_firestore/cloud_firestore.dart';
augment class User {
  static CollectionReference<User> collectionRef() => FirebaseFirestore.instance.collection('users').withConverter(
      fromFirestore: (snapshot, options) {
        final data = snapshot.data()!;
        data['id'] = snapshot.id;
        return User.fromJson(data);
      },
      toFirestore: (user, options) {
        return user.toJson();
      },
    );
  static DocumentReference<User> docRef(String id) => collectionRef().doc(id);

  external User.fromJson(prefix0.Map<prefix0.String, prefix0.Object?> json);
  external prefix0.Map<prefix0.String, prefix0.Object?> toJson();
  augment User.fromJson(prefix0.Map<prefix0.String, prefix0.Object?> json, )
      : this.id = json[r'id'] as prefix0.String,
        this.name = json[r'name'] as prefix0.String,
        this.age = json[r'age'] as prefix0.int;
  augment prefix0.Map<prefix0.String, prefix0.Object?> toJson() {
    final json = <prefix0.String, prefix0.Object?>{};
    json[r'id'] = this.id;
    json[r'name'] = this.name;
    json[r'age'] = this.age;
    return json;
  }
}