Top 5 tips for developing big projects using flutter.

• General

In this article, we will talk about Top 5 tips for developing big projects using flutter which can help flutter developers to improve the long-term complexity of big projects.

Top 5 tips for developing big projects using flutter.

Whenever a developer starts their new Flutter project it generally starts out small. But as time moves on the project starts getting bigger and bigger. In such cases finding out bugs, optimization of code and other tasks becomes extremely difficult. But there are some things which you can do to increase the efficiency of projects as well as developers. Below we have listed the top 5 tips for developing big projects using flutter.

Refactoring

When we discuss Flutter the most important thing is the widget. And there is a widget tree that is a result of nested widgets in code. If you have a simple UI in your code then it will be easy for you to re-read the code. But when an application or user interface is complex, it’ll require a large number of widgets. This will make our code less readable, less maintainable, and less efficient. 

As the widgets in your code grow larger, the widget tree grows and the code becomes harder to read. Refactoring is very important to improve the overall performance of your Flutter application. To do this, you can separate the various widgets from your own widget class. The goal is to keep the widget tree flat in any application. Refactoring takes advantage of rebuilding the Flutter subtree, which improves performance. Let`s have a look at some of the ways to refactor the Flutter application:

1) Refactoring with a method – With this technique, you only have to return the widget to the method call by its signature.

2) Refactoring with a local variable – It consists of initializing the widget with the final variable.

3) Refactoring with a widget class – This allows you to separate specific subtrees of your widget by extending the StatefullWidget and StatelessWidget classes.

Testing

The more features a Flutter application has, the harder it will be to test it manually. To overcome this you can use automated tests to ensure that the flutter application performs correctly without any bugs. To perform testing you can use the test package which provides the core framework for writing tests and the flutter_test package provides additional utilities for testing widgets. In Flutter, automated testing is classified into 3 broad categories:

• A unit test – A unit test tests a single function, method, or class. The main purpose of a unit test is to verify the correctness of a unit of logic under a different set of conditions. Unit tests don’t read from disk or write to disk, render to screen or receive user actions from outside the process running the test. 
• A widget test – A widget test tests a single widget. The goal of a widget test is to verify that the widget’s UI looks as expected and interacts as expected. Multiple classes are involved in testing a widget and it requires a test environment that can provide the appropriate widget lifecycle context.
• An integration test – An integration test tests a complete application or a large part of an application. The purpose of an integration test is to verify that all the widgets and services being tested work together as expected. Flutter developers can use integration tests to verify the app’s performance.

Theming

Imagine there is a flutter project that has grown exponentially bigger and you have colors scattered around the entire code. Now, what will you do if you want to add a dark theme or any color! You will have to go through your entire application to find the colors and make the correct changes to support this. Probably not such a good idea. There is a better way that is you can either define app-wide themes or use Theme widgets that define the colors and font styles for a particular part of the application. Flutter has ThemeData class with which you can define colors once in the theme & use it everywhere. When you later want to change colors, you can do it in one place and it will work everywhere.

• Creating an app theme – To share a Theme across an entire application, developers can provide a ThemeData class to the MaterialApp constructor. So, if no theme is provided, then Flutter will create a default theme for you. 
• Themes for part of an application – If you want to change the theme of only one part of an application, then you can wrap a section of the app in a Theme widget. So, there are two ways to perform this task: creating a unique ThemeData or extending the parent theme.

Linting

So, linting is the process of checking your source code for any programmatic and stylistic errors which are present in the code. You can use a lint tool (also known as linter) which is a collection of lint rules for Dart and Flutter projects. It analyzes source code to flag errors, bugs, stylistic errors, and suspicious constructs.

Moreover, linting is necessary to reduce errors and improve the quality of your Flutter code. By using lint tools you can speed up development and reduce costs by finding errors quickly. It would be better if you make a habit of setting up lint rules at the beginning of your project rather than after starting a project since the warnings to be fixed might add up later. There is a set of default linting configurations after setting up a project in an IDE but you can customize your own set of rules to have a well-formatted code. Rules are divided into 3 categories:

1. Error rules – These rules are for common errors that occur when coding.
2. Style rules – These are rules which focus on a style based on the Dart Style Guide.
3. Pub – These are pub-related rules.

Continuous Integration(C.I.) & Continuous Delivery(C.D.)

Continuous integration is a practice where developers regularly merge the changes in their code into a central repository, after which automated tests are run. By continuous delivery, the real-time changes done in code are automatically built, tested, and prepared for release. There are a number of continuous integration (C.I.) and continuous delivery (C.D.) methods that can help automate the delivery of applications. 

1. Fastlane + Firebase
2. Using Codemagic
3. GitHub Actions
4. Bitrise
5. Cirrus CI, Jenkins, Nevercode, etc.

CI/CD implementation has various benefits. Developers will be able to analyze, test and build the code every time they push a change. Also, developers have the choice to deploy the code whenever they want.

Conclusion:

Thanks for being with us on a Flutter Journey!

So, in this article, we have seen the Top 5 tips for developing big projects using flutter. Make sure to check out our other article related to Flutter. Also, feel free to comment and provide any other suggestions regarding Flutter.

Written by Abhishek Dhanani

Abhishek Dhanani, a skilled software developer with 3+ years of experience, masters Dart, JavaScript, TypeScript, and frameworks like Flutter and NodeJS. Proficient in MySQL, Firebase, and cloud platforms AWS and GCP, he delivers innovative digital solutions.