Jul 2, 2020.

We are pleased to announce the release of Scala.js 1.1.1!

This is mostly a bugfix release. In addition, it adds support for the new -Xasync flag of Scala 2.13.3 and 2.12.12 (see the release notes of Scala 2.13.3).

Read on for more details.

Getting started

If you are new to Scala.js, head over to the tutorial.

If you need help with anything related to Scala.js, you may find our community on Gitter and on Stack Overflow.

Bug reports can be filed on GitHub.

Release notes

If upgrading from Scala.js 0.6.x, make sure to read the release notes of Scala.js 1.0.0 first, as they contain a host of important information, including breaking changes.

This is a patch release:

• It is backward binary compatible with all earlier versions in the 1.x series: libraries compiled with 1.0.x and 1.1.0 can be used with 1.1.1 without change.
• It is forward binary compatible with 1.1.0: libraries compiled with 1.1.1 can be used with 1.1.0 without change.
• It is backward source compatible with 1.1.0: source code that used to compile with 1.1.0 should compile as is when upgrading to 1.1.1.

From Scala.js 1.1.0, which was a minor release:

• It is not forward binary compatible with 1.0.x: libraries compiled with 1.1.1 cannot be used with 1.0.x.
• It is not entirely backward source compatible with 1.0.x: it is not guaranteed that a codebase will compile as is when upgrading from 1.0.x (in particular in the presence of -Xfatal-warnings).

As a reminder, libraries compiled with 0.6.x cannot be used with Scala.js 1.x; they must be republished with 1.x first.

Miscellaneous

Upgrade to GCC v20200614

The Google Closure Compiler used internally by Scala.js for fullOptJS has been upgraded to v20200614.

Tools API reorganization

Some artifacts in the “Tools API”, i.e., the libraries used by build tools and other projects to programmatically link and run Scala.js code, have been reorganized:

• scalajs-logging, scalajs-js-envs, scalajs-js-envs-test-kit and scalajs-env-nodejs have been extracted in separate repositories, with their own versioning. They have all been published as version 1.1.1, but will evolve independently of Scala.js in the future.
• The Scala.js artifact for scalajs-logging has been discontinued, and its content absorbed by the Scala.js artifact for scalajs-linker.

If you depend on scalajs-js-envs or scalajs-env-nodejs, you should hard-code their version as 1.1.1 instead of deriving it from the version of Scala.js (e.g., using the scalaJSVersion constant).

Bug fixes

Among others, the following bugs have been fixed in 1.1.1:

• #4052 @JSExportTopLevel of def with default parameter causes IR checking error
• #4054 Empty jsEnvInput causes freeze (now eagerly reports an error instead)
• #4061 @JSExportTopLevel("default") generates invalid JS code on Scala.js 1.x (also see duplicate #4099)
• #4085 Failure to deserialize sjsir files in large projects
• #4086 Nested object within a top-level JS object not included in generated JavaScript
• #4088 BigDecimal(1, -2147483648).toString returns "1E-2147483648"
• #4089 Scala.js adds the ExposedJSMember annotation to NoSymbol (causing spurious recompilations in the incremental compiler)
• #4098 GCC crash in fullOptJS with ju.HashSet.remove
• #4105 Wrong codegen for switch with guards in statement position gives IR checking error

You can find the full list on GitHub.