armanbilge/fs2-dom

Idiomatic Cats Effect + FS2 integrations for Web APIs

fs2-dom

Idiomatic Cats Effect and FS2 integrations for Web APIs via scala-js-dom.

Usage

libraryDependencies += "com.armanbilge" %%% "fs2-dom" % "0.1.0-M1"

Features

• ReadableStream conversions
• EventTarget listeners
• Lifecycle-managed AbortSignals
• Wrappers for Clipboard, History, Lock, Storage APIs
• Serializable typeclass
• Contributions welcome!

fs2-dom's Issues

Dynosaur-inspired `Serializer`

https://systemfw.org/dynosaur/#/motivation

I have a sketch at a6ac0b8 but it needs more work.

Add wrapper for Window

https://developer.mozilla.org/en-US/docs/Web/API/Window

You can make one at the beginning of your application with Async, and then pass it down.

Remove Circe dependency

It is currently used here, to automatically derive a Serializer when a circe Encoder/Decoder are in scope. I added this for convenience.

fs2-dom/dom/src/main/scala/fs2/dom/Serializer.scala

Lines 52 to 59 in 443ca6b

	implicit def fromCirceCodec[F[_], A](implicit
	F: Sync[F],
	decoder: Decoder[A],
	encoder: Encoder[A]
	): Serializer[F, A] = new Serializer[F, A] {
	def serialize(a: A): F[js.Any] = F.delay(a.asJsAny)
	def deserialize(serialized: js.Any): F[A] = decodeJs[A](serialized).liftTo[F]
	}

While this is convenient, it is not a good long term solution. Namely:

1. Circe Json represents only a subset of serializable data structures. For example JS ArrayBuffer is serializable, but there is no way to express this in Json.
2. Circe Json also models stuff we can't serialize. For example, a JsonNumber maybe be arbitrarily large; however JavaScript-native numbers must be representable as Double.
3. Circe is still unstable, 0.15.x is currently in the works.

It's annoying, but what we need is our own infrastructure for deriving Serializers from data classes. We can use shapeless 3, and maybe take inspiration from Dynosaur.