What are the Lint rules in Flutter?

· 4 min read
What are the Lint rules in Flutter?

In this article, we will see what are the Lint rules in Flutter. We will also see how we can implement it in the flutter repository & how it helps to make our dart code effective.

What are the Lint rules in Flutter?

There are some packages that are available for us to implement linting into our flutter app that checks for programmatic and stylistic errors such as lint, analyzer, linter. All these packages help to keep the health of the code good and up to the dart standards.

Who linting helps?

The purpose of linting is to get real-time suggestions about identifying the hidden error that may improve the code quality or to identify bugs that may cause issues while running the app.

For example, if you use Text(“demo”) in any widget then the analyzer will show a warning Prefer const with constant constructors, it means you should keep this widget as const text(“demo”), which I think is really a good suggestion and most of the time we forget to initialize it using const keywords so I found that using linting is really good practice.

Writing new linting rules:

Now let us see how we can change our settings so that we get an error message every time we use the wrong dart code format. To do this we need to edit the analysis_option.yaml file.

  • Create an analysis_option.yaml file at the project level.
  • To show the error message we need to change the analyzer settings, in the analyzer we will change the error, warning, ignore, info preferences of individual rules, for example, missing_required_param: error, it will always show an error message every time you miss the required parameter.
  • Also, we will add the linter that will handle all the errors causing missing arguments or might improve the code quality. eg. avoid_empty_else this linter will show an error message whenever we will declare an empty else statement.

Enable and disable linting rules:

We can easily enable and disable linting rules:


    always_declare_return_types: false
    annotate_overrides: true

To analyze the code we need to run a dart analyzer in the terminal.

What happens when you add all the rules to an existing project?

You will get a number of issues, that might decrease your app performance. Also, it may cause any issue without an error message. So, it’s really important to know all the possible errors and solve them first.


This file contains all the linter and analyzer. You can add all the linter that can help you. Under the analyzer errors-tag, you can change the preferences of the linters whether you want to show errors or warnings related to that particular linter.


Thanks for being with us on a Flutter Journey!

So, in this article, we have seen the what are the Lint rules in Flutter. Make sure to check out our other article related to Flutter. Also, feel free to comment and provide any other suggestions regarding Flutter.

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