prefer_align_over_container

v0.1.0 Warning Fix Widget Replacement

Flags Container widgets that only use the alignment parameter (plus optional key and child). When Container is used solely for alignment, the Align widget is a lighter, more descriptive alternative.

Points the opposite way from prefer_container

This rule replaces a single-parameter Container with the specific widget, while prefer_container collapses 3 or more nested layout widgets into a Container.

The thresholds keep them from firing on the same code, but after further edits a fix from one rule can produce code the other flags. If that churn bothers you, enable only one direction.

The SDK’s avoid_unnecessary_containers is a third, non-overlapping case: it removes a Container that has no parameters at all.

Why use this rule

Container is a convenience widget that composes many lower-level widgets internally. When you only need alignment, using Align directly avoids the overhead and makes the intent clearer. It also makes the widget tree easier to understand at a glance.

See also: Align | Container

Don’t

// Container with only alignment parameter
Container(alignment: Alignment.topLeft, child: Text('Hello'));

// Container with only alignment, no child
Container(alignment: Alignment.bottomRight);

Do

// Use Align directly
Align(alignment: Alignment.topLeft, child: Text('Hello'));

Align(alignment: Alignment.bottomRight);

Configuration

This rule is in the opinionated preset, so it is on with preset: opinionated, or by name:

many_lints.yaml

rules:
  prefer_align_over_container: true

To turn it off again:

many_lints.yaml

rules:
  prefer_align_over_container: false

To keep the rule on but skip certain paths, use per-rule exclude.

Related rules

• prefer_container — Opposing convention. Replace sequences of nested widgets with a single Container.
• prefer_constrained_box_over_container — Use ConstrainedBox instead of Container when only constraints is set.
• prefer_padding_over_container — Use Padding instead of Container when only padding or margin is set.
• prefer_transform_over_container — Use Transform instead of Container when only transform is set.