Release strategy: 0.19 and 1.0

cats-1.0 is here. cats-effect-1.0 is imminent. fs2-1.0 is expected quickly thereafter. Dependency releases historically prompt http4s releases Let’s talk.

Goals:

• A stable release on cats/cats-effect/fs2-1.0 stack ASAP.
• Minimize disruptive upgrade cycles.
• Don’t release our 1.0 with known warts.
• Maintain no more than two branches (production release and master).

Proposal:

• A conservative 0.19.0 on fs2-1.0. EOL 0.18.x at this time.
• A glorious 1.0 when it’s done, with scalafix from 0.19.

Big ticket items under consideration which may or may not be considered for 0.19:

• HttpApp and HttpRoutes (#1693)
• scala.js support (#956)
• header reform (#1143)
• websockets as a response type instead of embedded in Response
• message typeclass (#1572)
• elimination of backticks
• cancellation support in blaze-server and servlet
• cancellation support in client
• URI reform (see sttp interpolator for inspiration)
• server and client creation that returns a Resource (relates to #1025)
• client form (#1772)
• investigate fastparse as FP-friendly alternative to parboiled2
• proxy support in blaze-client #1182
• websocket support in client
• scala-2.13 support (if the dependencies are there)

Breaking changes already in master.:

• Add accumulating version of circe EntityDecoder #1647
• Add ETag support to StaticFile #1652
• Reintroduce the option for fallthrough for authenticated services #1670
• Separate Cookie into RequestCookie and ResponseCookie #1676
• Add Eq[Uri] instance #1688
• Deprecate Message#withBody in favor of Message#withEntity. The latter returns a Message[F] rather than an F[Message[F]]. #1694
• Myriad new Arbitrary and Cogen instances #1677
• Add non-deprecated LocationResponseGenerator functions #1715
• Relax constraint on Router from Sync to Monad #1723
• Drop scodec-bits dependency #1732
• Add Show[ETag] instance #1749
• Replace fs2.Scheduler with cats.effect.Timer in Retry #1754
• Remove Sync constraint from EntityEncoder[Multipart] #1762
• async-http-client-2.4.2
• blaze-0.14
• scala-xml-1.1.0

For an initial pass, we’ll checked the things that belong in 0.19. Once we have a general consensus on strategy, we’ll use the milestone feature and more clearly define 0.19 and 1.0 and fight over the details.

[rossabaker]

We have a milestone, v0.19.0-M4, built on fs2-1.0.0 already. (There is an identical 0.19.0, but that was an error on my part). Look for an 0.19.1 on which we’ll support binary compatibility within a week or so.

[rossabaker]

Okay, to keep things moving:

• master will become 1.0.0-SNAPSHOT
• if it’s ready, it goes on master
• when fs2-1.0 release candidates draw near, we’ll evaluate whether to build an 0.19 off 0.18 plus carefully limited backports