Announcing Scala.js 1.3.1.

Author: sjrd

_config.yml

@@ -57,7 +57,7 @@ colors:  #in hex code if not noted else
 
 ### VERSIONS ###
 versions:
-  scalaJS: 1.3.0
+  scalaJS: 1.3.1
   scalaJSBinary: 1
   scalaJS06x: 0.6.33
   scalaJS06xBinary: 0.6

_posts/news/2020-11-16-announcing-scalajs-1.3.1.md

@@ -0,0 +1,115 @@
+---
+layout: post
+title: Announcing Scala.js 1.3.1
+category: news
+tags: [releases]
+permalink: /news/2020/11/16/announcing-scalajs-1.3.1/
+---
+
+
+We are pleased to announce the release of Scala.js 1.3.1!
+
+This release fixes the performance issues of the ECMAScript 2015 mode (the default) on Firefox.
+This fix **has a cost in terms of emitted code size**.
+Read more below about the trade-offs.
+
+In addition, this release fixes several other issues, including three regressions in 1.3.0 ([#4252](https://github.com/scala-js/scala-js/issues/4252), [#4268](https://github.com/scala-js/scala-js/issues/4268) and [#4271](https://github.com/scala-js/scala-js/issues/4271)).
+It also contains some improvements to the JDK support.
+
+Read on for more details.
+
+<!--more-->
+
+## Getting started
+
+If you are new to Scala.js, head over to [the tutorial]({{ BASE_PATH }}/tutorial/).
+
+If you need help with anything related to Scala.js, you may find our community [on Gitter](https://gitter.im/scala-js/scala-js) and [on Stack Overflow](https://stackoverflow.com/questions/tagged/scala.js).
+
+Bug reports can be filed [on GitHub](https://github.com/scala-js/scala-js/issues).
+
+## Release notes
+
+If upgrading from Scala.js 0.6.x, make sure to read [the release notes of Scala.js 1.0.0]({{ BASE_PATH }}/news/2020/02/25/announcing-scalajs-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 through 1.3.0 can be used with 1.3.1 without change.
+* It is forward binary compatible with 1.3.0: libraries compiled with 1.3.1 can be used with 1.3.0 without change.
+* It is backward source compatible with 1.3.0: source code that used to compile with 1.3.0 should compile as is when upgrading to 1.3.1.
+
+From Scala.js 1.3.0, which was a **minor** release:
+
+* It is *not* forward binary compatible with 1.2.x: libraries compiled with 1.3.1 cannot be used with 1.2.x or earlier.
+* It is *not* entirely backward source compatible: it is not guaranteed that a codebase will compile *as is* when upgrading from 1.2.x or earlier (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.
+
+## Performance fix on Firefox and code size increase
+
+Scala.js code has been known for bad performance on Firefox with the default output mode of ECMAScript 2015.
+
+**This release fixes this issue, but at the cost of increased emitted code size.**
+
+If you have been using the following setting to avoid bad performance on Firefox, you can now remove it:
+
+{% highlight scala %}
+// This was necessary before 1.3.1 to avoid bad performance on Firefox
+scalaJSLinkerConfig ~= { _.withESFeatures(_.withUseECMAScript2015(false)) }
+{% endhighlight %}
+
+If your codebase does not target the Web nor any SpiderMonkey-based environment, you may want to trade it away for the better code size from before.
+You can tell Scala.js that avoiding `class`es is not necessary with the following setting:
+
+{% highlight scala %}
+// Trade away decent Firefox performance for a smaller output
+scalaJSLinkerConfig ~= { _.withESFeatures(_.withAvoidClasses(false)) }
+{% endhighlight %}
+
+It turns out that SpiderMonkey, the JavaScript engine of Firefox, exhibits severe performance penalties for JavaScript `class`es.
+This has caused slowdowns for Scala.js code of up to 10x compared to other browsers and compared to the ECMAScript 5.1 mode.
+Starting from Scala.js 1.3.1, we restrict the usage of `class`es in the emitted JavaScript to the minimum required for correct semantics.
+We fall back to `function`s and `prototype`s for the majority of the emitted code.
+
+## Miscellaneous
+
+### Better support of Scala 3 in sbt-scalajs
+
+The sbt plugin now has better support for Scala 3 codebases.
+In particular, the JUnit support works out of the box with `enablePlugins(ScalaJSJUnitPlugin)`.
+It is also future-proof for when sbt will support Scala 3 out of the box, rather than requiring `sbt-dotty`.
+
+These improvements are only available for Scala >= 3.0.0-M1.
+The 0.x versions are not supported.
+
+### New JDK APIs
+
+This release contains some improvements in the JDK APIs that we support:
+
+New classes:
+
+* `java.lang.ClassValue`
+
+New methods:
+
+* `new java.util.HashMap(initialCapacity: Int, loadFactor: Float)`
+* `java.util.Objects.requireNonNull(obj: T, message: Supplier[String])`
+
+Methods with fixed or improved behavior:
+
+* In `java.util.regex.Matcher`:
+  * `lookingAt()` and `matches()` ([#4252](https://github.com/scala-js/scala-js/issues/4252))
+  * `reset()` ([#4254](https://github.com/scala-js/scala-js/issues/4254))
+* `java.util.Formatter` and derivatives (such as `String.format`) now support `java.math.BigInteger` arguments with the `%d`, `%x` and `%o` conversions
+
+## Bug fixes
+
+Among others, the following bugs have been fixed in 1.3.1:
+
+* [#4252](https://github.com/scala-js/scala-js/issues/4252) `regex.Matcher.lookingAt()` and `matches()` incorrect in 1.3.0
+* [#4268](https://github.com/scala-js/scala-js/issues/4268) Native superclass of a non-native JS class is not imported (1.3.0 regression)
+* [#4271](https://github.com/scala-js/scala-js/issues/4271) Scala.js 1.3.0 fails to fastOptJS/fullOptJS when the project has no exports nor the module initializer
+* [#4254](https://github.com/scala-js/scala-js/issues/4254) `Matcher.reset()` does not reset the region
+* [#4281](https://github.com/scala-js/scala-js/issues/4281) Bad error message when trying to define `apply` in an anonymous class extending `js.Function`
+
+You can find the full list [on GitHub](https://github.com/scala-js/scala-js/issues?q=is%3Aissue+milestone%3Av1.3.1+is%3Aclosed).

doc/all-api.md

@@ -5,6 +5,15 @@ title: All previous versions of the Scala.js API
 
 ## All previous versions of the API
 
+### Scala.js 1.3.1
+* [1.3.1 scalajs-library]({{ site.production_url }}/api/scalajs-library/1.3.1/scala/scalajs/js/index.html)
+* [1.3.1 scalajs-test-interface]({{ site.production_url }}/api/scalajs-test-interface/1.3.1/)
+* [1.3.1 scalajs-ir]({{ site.production_url }}/api/scalajs-ir/1.3.1/org/scalajs/ir/index.html)
+* [1.3.1 scalajs-linker-interface]({{ site.production_url }}/api/scalajs-linker-interface/1.3.1/org/scalajs/linker/interface/index.html) ([Scala.js version]({{ site.production_url }}/api/scalajs-linker-interface-js/1.3.1/org/scalajs/linker/interface/index.html))
+* [1.3.1 scalajs-linker]({{ site.production_url }}/api/scalajs-linker/1.3.1/org/scalajs/linker/index.html) ([Scala.js version]({{ site.production_url }}/api/scalajs-linker-js/1.3.1/org/scalajs/linker/index.html))
+* [1.3.1 scalajs-test-adapter]({{ site.production_url }}/api/scalajs-sbt-test-adapter/1.3.1/org/scalajs/testing/adapter/index.html)
+* [1.3.1 sbt-scalajs]({{ site.production_url }}/api/sbt-scalajs/1.3.1/#org.scalajs.sbtplugin.package)
+
 ### Scala.js 1.3.0
 * [1.3.0 scalajs-library]({{ site.production_url }}/api/scalajs-library/1.3.0/scala/scalajs/js/index.html)
 * [1.3.0 scalajs-test-interface]({{ site.production_url }}/api/scalajs-test-interface/1.3.0/)

doc/internals/version-history.md

@@ -5,6 +5,7 @@ title: Version history
 
 ## Version history of Scala.js
 
+- [1.3.1](/news/2020/11/16/announcing-scalajs-1.3.1/)
 - [1.3.0](/news/2020/10/16/announcing-scalajs-1.3.0/)
 - [1.2.0](/news/2020/09/09/announcing-scalajs-1.2.0/)
 - [1.1.1](/news/2020/07/02/announcing-scalajs-1.1.1/)