damn_nullable

A tiny and clean Dart utility that solves a classic problem:

In a normal copyWith, you cannot distinguish between:

  • not providing a value no update
  • providing null update field to null

This prevents models from correctly handling nullable fields.

damn_nullable solves this with a simple wrapper:

DamnNullable("John")   // update field to "John"
DamnNullable(null)      // update field to null
// omit parameter        // no update

This gives you full control over nullable updates.

Usage

Import the package:

import 'package:damn_nullable/damn_nullable.dart';

Example model

class User {
  final String? name;
  final int? age;

  User({this.name, this.age});

  User copyWith({
    DamnNullable<String>? name,
    DamnNullable<int>? age,
  }) {
    return User(
      name: name?.or(this.name) ?? this.name,
      age: age?.or(this.age) ?? this.age,
    );
  }
}

Updating fields

Update to a new value

user.copyWith(name: DamnNullable("John"));

Explicitly set field to null

user.copyWith(name: DamnNullable(null));

Do not update the field

user.copyWith();

How .or() works

Inside copyWith, this expression:

name?.or(this.name)

means:

  • If a DamnNullable was passed, return the wrapped value
  • If the parameter was not passed, return the fallback (existing value)

So:

Input Behavior
DamnNullable("John") updates to "John"
DamnNullable(null) updates to null
parameter omitted keeps existing value

When should you use damn_nullable?

  • You have models with nullable fields
  • You want clean copyWith behavior
  • You want to intentionally set fields to null
  • You want a tiny, readable solution

Why "damn_nullable"?

Because sometimes you really need to say:

"Damn it, I meant to set this field to null!"

Contributing

Issues and PRs are welcome on GitHub.

License

MIT License.

Libraries

damn_nullable