cdmunoz

Agent-Driven Development: an orchestrated SDLC for Flutter

Companion material for the talk "The terminal as a Jujutsu School" — FlutterConf LATAM 2026, Cancún.

These are adaptable templates, distilled from a real agent setup used to ship a production Flutter app. The pattern is the point; the specifics of any one codebase are not. Everything here is written to be copied into your repo and rewritten for your stack.

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/// Stub that holds all of the values in memory
class StubStorage implements Storage {
  final hash = <String, dynamic>{};

  @override
  bool? getBool(String key) => hash[key] as bool?;

  @override
  String? getString(String key) => hash[key] as String?;

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Response<T> buildFailureResponse<T>(
  String message, {
  int code = 400,
  http.BaseRequest? request,
}) {
  final body = jsonDecode(message) as Map<String, dynamic>;
  final error = buildBackendError(statusCode: code, body: body);

  return Response(
    http.Response(message, code, request: request),

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Response<T> buildFailureResponse<T>(
  String message, {
  int code = 400,
  http.BaseRequest? request,
}) {
  final body = jsonDecode(message) as Map<String, dynamic>;
  final error = buildBackendError(statusCode: code, body: body);

  return Response(
    http.Response(message, code, request: request),

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Response<T> buildFailureResponse<T>(
  String message, {
  int code = 400,
  http.BaseRequest? request,
}) {
  final body = jsonDecode(message) as Map<String, dynamic>;
  final error = buildBackendError(statusCode: code, body: body);

  return Response(
    http.Response(message, code, request: request),

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    group('with a success', () {
      setUpAll(() async {
        when(pushNotifier.requestPermissions()).thenSucceed(true);
        when(pushNotifier.onTokenRefresh()).thenStream(fcmRefreshedToken);

        await subject().onInit();
      });

      test('ask for push permissions', () {
        verify(pushNotifier.requestPermissions());

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/// mocking the PostExpectation with a Future
extension FutureMock<T> on PostExpectation<Future<T>> {
  void thenFuture(T body) {
    thenAnswer((realInvocation) => Future.value(body));
  }
}

/// we use Result objet similar than a monad which returns a success, a failure, etc
/// this extension mocks a Result of success, failure or in order

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await onErrorRetry(
        doIt: () async {
          await _twilioModule.setup();

          _analytic.track('Platform Loaded');

          _router.replaceTo(HomeRoute());

          status = status.rebuild((b) => b..isLoadingVisible = false);
        },

cdmunoz

typedef FunctionOnRetry = Function(
  dynamic ex,
  int retryCount,
  int retryInMilliseconds,
);

Future<void> onErrorRetry({
  required Future Function() doIt,
  required FunctionOnRetry onRetry,
  required int maxRetries,

cdmunoz

/// this class uses Isolates.run, only available after Dart 2.19, allowing in parallel obtaining a file in bytes 
/// then answering to its caller without blocking the UI
/// remember: when using isolates, the functions they call must be top level or static

import 'dart:isolate';

import 'package:flutter/foundation.dart';
import 'package:http/http.dart' as http;

Future<http.Response> _fileResponse(Uri uri) async {