Expose TaggedRecord (#70)

Fixes bug with nested unions being untagged (#61)

Fix no-arg check to avoid matching objects with all optional properties (#48)

Ban TagProp as a usable property in variants when no ValProp is used (#56). This is technically a breaking change but probably won't break code that didn't have latent bugs.

Fix for TypeScript 3.4 when using arrays for values:

const Foo = unionize({ array: ofType<boolean[]>() }, { value: 'value' });

// no type error in unionize@<=2.1.2 under [email protected]:
Foo.array('whoops');

Fixes #39

Fixes #34

Allow including tags in variant types, so that you can name your variants with interfaces:

interface Foo {
  tag: 'foo';
  x: number;
}

interface Bar {
  tag: 'bar';
  y: boolean;

const T = unionize({
  foo: ofType<Foo>(),
  bar: ofType<Bar>(),
});

Breaking changes

• A new API for specifying the default case (using key default in the cases object) (#19)
• Specify tag and value property names via a config object instead of positional arguments (#22)

Other enhancements

• Uncurried variants of match (#21)
• A simplified version of match, transform, for creating functions of the union type to itself (#23)
• Creation functions for variants of value type {} no longer require an argument (#31)
• Hygienic type operators UnionOf, RecordOf, TagsOf for extracting the types associated with a unionized object (#32)

Bug fixes

• Fix issue where _Record wasn't using the actual object that was passed in (#20)

See the README for more details. Thanks to @twop for his significant contributions to this release!

Fixes #16.