Announcing Scala.js 1.6.0.

_config.yml

@@ -64,7 +64,7 @@ colors: #in hex code if not noted else
 
 ### VERSIONS ###
 versions:
- scalaJS: 1.5.1
+ scalaJS: 1.6.0
  scalaJSBinary: 1
  scalaJS06x: 0.6.33
  scalaJS06xBinary: 0.6

_data/library/versions.yml

@@ -26,3 +26,4 @@
 - 1.3.0
 - 1.4.0
 - 1.5.0
+- 1.6.0

_posts/news/2021-06-09-announcing-scalajs-1.6.0.md

@@ -0,0 +1,144 @@
+---
+layout: post
+title: Announcing Scala.js 1.6.0
+category: news
+tags: [releases]
+permalink: /news/2021/06/09/announcing-scalajs-1.6.0/
+---
+
+
+We are excited to announce the release of Scala.js 1.6.0!
+
+This release fixes a number of bugs and brings new interoperability features, notably `js.import.meta`.
+It also brings new facades for `js.WeakRef` and `js.FinalizationRegistry`, while proper implementations of `java.lang.ref.*` are moved to separate libraries.
+
+The Scala standard library was upgraded to versions 2.12.13 and 2.13.5.
+
+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 **minor** release:
+
+* It is backward binary compatible with all earlier versions in the 1.x series: libraries compiled with 1.0.x through 1.5.x can be used with 1.6.0 without change.
+* It is *not* forward binary compatible with 1.5.x: libraries compiled with 1.6.0 cannot be used with 1.5.x or earlier.
+* It is *not* entirely backward source compatible: it is not guaranteed that a codebase will compile *as is* when upgrading from 1.5.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.
+
+## Fixes with compatibility concerns
+
+### Classes in `java.lang.ref.*` have been moved to separate libraries
+
+Until Scala.js 1.5.x, the core library contained stub implementations of the classes in `java.lang.ref.*`, such as `WeakReference`.
+These implementations did not respect the weak semantics, and instead held *strong* references.
+Despite linking and successfully running, code using `WeakReference` et al. was therefore stubtly wrong.
+
+Since this goes against our policy for the standard library that linking code must be correct, we have removed those stubs from the core library.
+To preserve binary compatibility, we introduce two variants of a library that provides the removed pieces:
+
+* [`scalajs-fake-weakreferences`](https://github.com/scala-js/scala-js-fake-weakreferences) is an exact copy of what used to ship in Scala.js core; it can be used as a drop-in replacement when upgrading to Scala.js 1.6.0.
+* [`scalajs-weakreferences`](https://github.com/scala-js/scala-js-weakreferences) provides a *correct* implementation of `WeakReference` and `ReferenceQueue` instead, but relies on ECMAScript 2021's built-in `WeakRef` and `FinalizationRegistry`; it can be used for new code.
+
+Due to the removal from the core library, you may encounter linking errors when upgrading to Scala.js 1.6.0, such as:
+
+{% highlight text %}
+[error] Referring to non-existent class java.lang.ref.WeakReference
+[error] called from helloworld.HelloWorld$.main([java.lang.String)void
+[error] called from static helloworld.HelloWorld.main([java.lang.String)void
+[error] called from core module module initializers
+[error] involving instantiated classes:
+[error] helloworld.HelloWorld$
+{% endhighlight %}
+
+You may fix these linking errors by adding the following dependency to your `libraryDependencies`:
+
+{% highlight scala %}
+"org.scala-js" %%% "scalajs-fake-weakreferences" % "1.0.0"
+{% endhighlight %}
+
+We encourage you to try and get rid of that dependency when you get the chance, since it is (intentionally) broken.
+
+## `js.import.meta`
+
+ECMAScript 2020 introduced the meta-property `import.meta`, which provides host-dependent information about the enclosed module.
+Until Scala.js 1.5.x, there was no way to access that meta-property.
+Scala.js 1.6.0 introduces a new primitive to address that shortcoming:
+
+{% highlight scala %}
+import scala.scalajs.js
+
+val moduleMetaInfo: js.Dynamic = js.`import`.meta
+println(moduleMetaInfo.url) // Node.js-specific
+{% endhighlight %}
+
+Since `import.meta` is only valid in an ES module, using `js.import.meta` requires to [emit the Scala.js code as an `ESModule`]({{ BASE_PATH }}/doc/project/module.html).
+Failing to do so will result in a linking error such as
+
+{% highlight text %}
+[error] Uses import.meta with a module kind other than ESModule
+[error] called from helloworld.HelloWorld$.main([java.lang.String)void
+[error] called from static helloworld.HelloWorld.main([java.lang.String)void
+[error] called from core module module initializers
+[error] involving instantiated classes:
+[error] helloworld.HelloWorld$
+{% endhighlight %}
+
+## Miscellaneous
+
+### New facades for the JavaScript standard library
+
+The following definitions for ECMAScript 2021 library features were added:
+
+* `js.WeakRef`
+* `js.FinalizationRegistry`
+
+### Upgrade to JUnit 4.13.2
+
+The Scala.js version of JUnit has been updated to match the API of JUnit 4.13.2.
+The most important change is the addition of `org.junit.Assert.assertThrows`.
+
+### New configuration for the target ECMAScript version
+
+Until Scala.js 1.5.x, one could only choose between targeting ECMAScript 5.1 or ECMAScript 2015, based on the following setting:
+
+{% highlight scala %}
+scalaJSLinkerConfig ~= { _.withESFeatures(_.withUseECMAScript2015(false)) } // default true
+{% endhighlight %}
+
+It is now possible to choose any known ECMAScript version since 5.1, using the following setting:
+
+{% highlight scala %}
+scalaJSLinkerConfig ~= (_.withESFeatures(_.withESVersion(ESVersion.ES2018))) // default ES2015
+{% endhighlight %}
+
+Possible values are `ES5_1` and `ES2015` through `ES2020`.
+We will add further choices in the future, as new versions of ECMAScript are released.
+
+The Scala.js linker and libraries may choose to optimize the resulting code, or offer more features, based on the target ECMAScript version.
+As of Scala.js 1.6.0, choices greater than `ES2015` are only used for optimizations.
+
+### Upgrade to GCC v20210406
+
+We upgraded to the Google Closure Compiler v20210406.
+
+## Bug fixes
+
+Among others, the following bugs have been fixed in 1.6.0:
+
+* [#4466](https://github.com/scala-js/scala-js/issues/4466) 1 ULP error when toFloat is called for some long values
+* [#4499](https://github.com/scala-js/scala-js/issues/4499) FewestModules can result in filenames that are greater than 255 Characters
+
+You can find the full list [on GitHub](https://github.com/scala-js/scala-js/issues?q=is%3Aissue+milestone%3Av1.6.0+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 1.6.0
+* [1.6.0 scalajs-library]({{ site.production_url }}/api/scalajs-library/1.6.0/scala/scalajs/js/index.html)
+* [1.6.0 scalajs-test-interface]({{ site.production_url }}/api/scalajs-test-interface/1.6.0/)
+* [1.6.0 scalajs-ir]({{ site.production_url }}/api/scalajs-ir/1.6.0/org/scalajs/ir/index.html)
+* [1.6.0 scalajs-linker-interface]({{ site.production_url }}/api/scalajs-linker-interface/1.6.0/org/scalajs/linker/interface/index.html) ([Scala.js version]({{ site.production_url }}/api/scalajs-linker-interface-js/1.6.0/org/scalajs/linker/interface/index.html))
+* [1.6.0 scalajs-linker]({{ site.production_url }}/api/scalajs-linker/1.6.0/org/scalajs/linker/index.html) ([Scala.js version]({{ site.production_url }}/api/scalajs-linker-js/1.6.0/org/scalajs/linker/index.html))
+* [1.6.0 scalajs-test-adapter]({{ site.production_url }}/api/scalajs-sbt-test-adapter/1.6.0/org/scalajs/testing/adapter/index.html)
+* [1.6.0 sbt-scalajs]({{ site.production_url }}/api/sbt-scalajs/1.6.0/#org.scalajs.sbtplugin.package)
+
 ### Scala.js 1.5.1
 * [1.5.1 scalajs-library]({{ site.production_url }}/api/scalajs-library/1.5.1/scala/scalajs/js/index.html)
 * [1.5.1 scalajs-test-interface]({{ site.production_url }}/api/scalajs-test-interface/1.5.1/)

doc/internals/version-history.md

@@ -5,6 +5,7 @@ title: Version history
 
 ## Version history of Scala.js
 
+- [1.6.0](/news/2021/06/09/announcing-scalajs-1.6.0/)
 - [1.5.1](/news/2021/04/01/announcing-scalajs-1.5.1/)
 - [1.5.0](/news/2021/02/12/announcing-scalajs-1.5.0/)
 - [1.4.0](/news/2021/01/12/announcing-scalajs-1.4.0/)