v2.0.1

• TypeScript-only: Fix definition of JSONObject to reflect that its values might always be undefined as well.

• TypeScript-only: Changed return types of { [key: string]: T } to Record<string, T>.

• TypeScript-only: Fine-tune the type of instanceOf().

v2.0.0

This is a breaking change, which brings numerous benefits:

• A simpler API 😇
• Smaller bundle size (67% reduction 😱)
• Tree-shaking support 🍃
• Runtime speed 🏎️
• Better documentation 📚
• Better support for writing your own decoders 🛠️

Please see the migration guide for precise instructions on how to
adjust your v1 code.

The main change is the brand new Decoder<T> API! The tl;dr is:

Replace this v1 pattern...		...with this v2 API	Notes
mydecoder(input)	→	mydecoder.decode(input)	migration instructions
guard(mydecoder)(input)	→	mydecoder.verify(input)	migration instructions
map(mydecoder, ...)	→	mydecoder.transform(...)	migration instructions
compose(mydecoder, predicate(...))	→	mydecoder.refine(...)	migration instructions
describe(mydecoder, ...)	→	mydecoder.describe(...)
mydecoder(input).value()	→	mydecoder.value(input)
either, either3, ..., either9	→	either	migration instructions
tuple1, tuple2, ... tuple6	→	tuple	migration instructions
dispatch	→	taggedUnion	migration instructions
url(...)	→	httpsUrl / url (signature has changed)	migration instructions

The full documentation is available on decoders.cc.

Other features:

• Include ES modules in published NPM builds (yay tree-shaking! 🍃)
• Much smaller total bundle size (67% smaller compared to v1 😱)

Other potentially breaking changes:

• Drop support for all Node versions below 12.x
• Drop support for TypeScript versions below 4.1.0
• Drop support for Flow versions below 0.142.0
• Drop all package dependencies
• Direct reliance on lemons has been removed

New decoders:

• always
• anyNumber
• never
• prep()
• set()
• uuid
• uuidv1
• uuidv4

Other improvements:

• optional(),
  nullable(), and
  maybe() now each take an optional 2nd param to
  specify a default value
• Better error messages for nested eithers

Implementation changes:

• Major reorganization of internal module structure
• Various simplification of internals

v2.0.0-beta13

Upgrading to v2 can, but doesn't have to be a breaking change for you. If upgrading causes errors for you, please see the migration guide for instructions.

v1.25.5

• Fix compatibility issue with TypeScript projects configured with
  strictNullChecks: false (or strict: false) (Thanks, @stevekrouse and @djlauk!)

• Officially support Node 16.x

v1.25.4

• Expose nonEmptyArray function in TypeScript (Thanks, @mszczepanczyk!)

v1.25.3

• Argument to constant(...) now has to be scalar value in both Flow and TypeScript,
  which matches its intended purpose.

v1.25.2

• Avoid the need for having to manually specify "as const" in TypeScript when using
  constant(). (Thanks, @schmod!)

v1.25.1

• Add support for Flow 0.154.0

v1.25.0

• Fix signature of oneOf() to reflect it can only be used with scalar/constant values

• In TypeScript, the inferred type for oneOf(['foo', 'bar']) will now be Decoder<'foo' | 'bar'> instead of Decoder<string> 🎉

• Drop support for Flow versions < 0.115.0

v1.24.1

• Tighten up signature types to indicate that incoming arrays won't get mutated