# `dart fix`

## What is it?

`dart fix` is a command line tool and part of the regular `dart` tool. It is
used to batch apply fixes for analysis issues.

## How does it work?

`dart fix` runs over your project looking for analysis issues. For each issue it
checks whether there is an automated fix that can be applied. These fixes are
generally either in response to a lint or hint in your code, or part of upgrading
your source to newer package APIs.

For the first type of change, the fixes are generally in response to the set of
lints and analysis configuration specified in your [analysis_options.yaml] file.

The second type of change - upgrading to newer package APIs - is performed
based on API changes defined for specific packages. This declarative definition
of the API changes lives in a `fix_data.yaml` file in the package's `lib/`
directory; for details see the [documentation](https://github.com/flutter/flutter/wiki/Data-driven-Fixes).

## Command line usage

```
Apply automated fixes to Dart source code.

This tool looks for and fixes analysis issues that have associated automated fixes.

To use the tool, run either 'dart fix --dry-run' for a preview of the proposed changes for a project, or 'dart fix --apply' to
apply the changes.

Usage: dart fix [arguments]
-h, --help       Print this usage information.
-n, --dry-run    Preview the proposed changes but make no changes.
    --apply      Apply the proposed changes.

Run "dart help" to see global options.
```

[analysis_options.yaml]: https://dart.dev/tools/analysis