Enum from String

As from Dart version 2.15, you can lookup an enum value by name a lot more conveniently, using .values.byName or using .values.asNameMap():

enum Visibility {
  visible, collapsed, hidden
}

void main() {
  // Both calls output `true`
  print(Visibility.values.byName('visible') == Visibility.visible);
  print(Visibility.values.asNameMap()['visible'] == Visibility.visible);
}

You can read more about other enum improvements in the official Dart 2.15 announcement blog post.

Mirrors aren't always available, but fortunately you don't need them. This is reasonably compact and should do what you want.

enum Fruit { apple, banana }

// Convert to string
String str = Fruit.banana.toString();

// Convert to enum
Fruit f = Fruit.values.firstWhere((e) => e.toString() == 'Fruit.' + str);

assert(f == Fruit.banana);  // it worked

Thanks to @frostymarvelous for correcting the answer