proposal: `ternary_operator_with_empty_widget`

[asashour]

ternary_operator_with_empty_widget

Description

Avoid having a ternary condition operator with an empty widget inside a collection.

Details

There is no need to have a ternary operator when one of the expressions is an empty widget, e.g. SizedBox() or Container(). A collection if can be used instead.

Kind

Avoid

Bad Examples

Column(
  children: [
    inTheSky ? const Text('Flying') : const SizedBox(),
  ],
),

Column(
  children: [
    inTheSky ? const Text('Flying') : Container(),
  ],
),

Column(
  children: [
    !inTheSky ? const SizedBox.shrink() : const Text('Flying'),
  ],
),

Good Examples

Column(
  children: [
    if (inTheSky) const Text('Flying'),
  ],
),

Discussion

Having if inside an array, is probably not intuitive for new users.

Discussion checklist

• [ ] List any existing rules this proposal modifies, complements, overlaps or conflicts with.
• [ ] List any relevant issues (reported here, the SDK Tracker, or elsewhere).
• [ ] If there's any prior art (e.g., in other linters), please add references here.
• [ ] If this proposal corresponds to Effective Dart or Flutter Style Guide advice, please call it out. (If there isn't any corresponding advice, should there be?)
• [ ] If this proposal is motivated by real-world examples, please provide as many details as you can. Demonstrating potential impact is especially valuable.

[bwilkerson]

How often do users produce code that looks like this unintentionally?

That is, how big of a problem is it?

How often do users produce code that looks like this intentionally in order to keep the right layout? How often to users temporarily produce code that looks like this, intending to populate the children of the widget?

That is, how often will this result in false positives?

My guess is that it will produce false positives more often than it will catch valid errors.

@goderbauer For a more informed opinion.