Announcing Scala.js 1.7.0.

_config.yml

@@ -64,7 +64,7 @@ colors:  #in hex code if not noted else
 
 ### VERSIONS ###
 versions:
-  scalaJS: 1.6.0
+  scalaJS: 1.7.0
   scalaJSBinary: 1
   scalaJS06x: 0.6.33
   scalaJS06xBinary: 0.6

_data/doc.yml

@@ -55,6 +55,9 @@
       url: /doc/all-api.html
 - text: Semantics of Scala.js
   url: /doc/semantics.html
+  subitems:
+    - text: Regular expressions
+      url: /doc/regular-expressions.html
 - text: Internals
   url: /doc/internals/
   subitems:

_data/library/versions.yml

@@ -27,3 +27,4 @@
 - 1.4.0
 - 1.5.0
 - 1.6.0
+- 1.7.0

_posts/news/2021-08-04-announcing-scalajs-1.7.0.md

@@ -0,0 +1,149 @@
+---
+layout: post
+title: Announcing Scala.js 1.7.0
+category: news
+tags: [releases]
+permalink: /news/2021/08/04/announcing-scalajs-1.7.0/
+---
+
+
+We are excited to announce the release of Scala.js 1.7.0!
+
+This release fixes a number of bugs.
+In particular, regular expressions, available through `java.util.regex.Pattern` or Scala's `Regex` and `.r` method, now behave in the same way as on the JVM.
+This change has compatibility implications, which we discuss below.
+
+Moreover, this release fixes *all* the known bugs that were left.
+As of this writing, Scala.js 1.7.0 has zero known bugs!
+
+The Scala standard library was upgraded to versions 2.12.14 and 2.13.6.
+
+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 1.6.x can be used with 1.7.0 without change.
+* It is *not* forward binary compatible with 1.6.x: libraries compiled with 1.7.0 cannot be used with 1.6.x or earlier.
+* It is *not* entirely backward source compatible: it is not guaranteed that a codebase will compile *as is* when upgrading from 1.6.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
+
+### Regular expressions have been fixed to match the JVM behavior
+
+Until Scala.js 1.6.x, the regular expressions provided by `java.util.regex.Pattern`, and used by `scala.util.matching.Regex` and the `.r` method, were implemented directly in terms of JavaScript's `RegExp`.
+That meant that they used the feature set and the semantics of [JavaScript regular expressions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions), which are different from [Java regular expressions](https://docs.oracle.com/en/java/javase/15/docs/api/java.base/java/util/regex/Pattern.html).
+Scala.js 1.7.0 finally fixes this issue, and now correctly implements the semantics of Java regular expressions, although some features are not supported.
+
+Since the old implementation has been there for 7 years, and documented as such, it is possible that this fix will actually break some code in the wild.
+During the implementation of this feature, we have analyzed the corpus of all Scala.js-only libraries (without JVM support) and extracted all the regexes that they use.
+We have verified that none of those use cases are impacted by this change.
+It is still possible that applications are impacted.
+
+It is also possible for some cross-platform libraries to face issues, as we have not covered those.
+Unlike Scala.js-only libraries, we consider it unlikely that they will have issues with the *change of semantics* per se, as they already worked on the JVM, with the new semantics.
+
+The biggest danger would be a cross-library that uses the `MULTILINE` flag (aka `(?m)`).
+Indeed, that feature kind of worked before, but is now rejected at `Pattern.compile()`-time with a `PatternSyntaxException` by default.
+The reason is that to correctly implement the semantics of that flag, we need support for look-behind assertions (`(?<=𝑋)`) in JavaScript's `RegExp`.
+That support was only added in ECMAScript 2018, whereas Scala.js targets ES 2015 by default.
+
+It is possible to change that target with the following setting:
+
+{% highlight scala %}
+scalaJSLinkerConfig ~= (_.withESFeatures(_.withESVersion(ESVersion.ES2018)))
+{% endhighlight %}
+
+**Attention!** While this enables support for the `MULTILINE` flag (among others), it restricts your application to environments that support recent JavaScript features.
+If you maintain a library, this restriction applies to all downstream libraries and applications.
+
+We therefore recommend to try and *avoid* the need for that flag instead.
+We give several strategies on how to do so [on the Regular expressions documentation page]({{ BASE_PATH }}/doc/regular-expressions.html).
+That page also contains many more details on the new support of regular expressions.
+
+## New features
+
+### Add a configurable header comment in generated .js files
+
+Sometimes, it is desirable to add a header comment in the generated .js files.
+This is typically used for license information or any other metadata.
+While it has always been possible to post-process the generated .js files in the build, doing so came at the cost of destroying the source maps.
+
+Scala.js 1.7.0 introduces a new linker configuration, `jsHeader`, to specify a comment to insert at the top of .js files:
+
+{% highlight scala %}
+scalaJSLinkerConfig ~= {
+  _.withJSHeader(
+    """
+      |/* This is the header, which source maps
+      | * take into account.
+      | */
+    """.stripMargin.trim() + "\n"
+  )
+}
+{% endhighlight %}
+
+The `jsHeader` must be a combination of valid JavaScript whitespace and/or comments, and must not contain any newline character other than `\n` (the UNIX newline).
+If non-empty, it must end with a new line.
+These restrictions ensure that this feature is not abused to inject arbitrary JavaScript code in the .js file generated by the compiler, potentially compromising the compiler abstractions.
+
+## Miscellaneous
+
+### Allow delegating JS class constructor calls with default params
+
+Until Scala.js 1.6.x, in a JS class, a secondary constructor calling another constructor with default parameters had to specify actual values for all parameters.
+For example, the following code was rejected:
+
+{% highlight scala %}
+class A(x: Int, y: String = "default") extends js.Object {
+  def this() = this(12)
+}
+{% endhighlight %}
+
+That restriction has been lifted in Scala.js 1.7.0, so that the above code is now valid.
+
+### New JDK APIs
+
+The following JDK classes have been added
+
+* `java.util.concurrent.atomic.LongAdder`
+
+### Set up the `versionScheme` of library artifacts
+
+This release configures the sbt `versionScheme` setting for the library artifacts of Scala.js (with `"semver-spec"` for the public ones).
+This will reduce spurious eviction warnings in downstream projects.
+
+### Upgrade to GCC v20210601
+
+We upgraded to the Google Closure Compiler v20210601.
+
+## Bug fixes
+
+Among others, the following bugs have been fixed in 1.7.0:
+
+* [#4507](https://github.com/scala-js/scala-js/issues/4507) 1.6.0 regression: `new mutable.WrappedArrayBuilder(classTag[Unit]).result()` throws a CCE
+* [#3953](https://github.com/scala-js/scala-js/issues/3953) fastOptJS error in scalaz 7.3 with Scala.js 1.0.0
+* [#3918](https://github.com/scala-js/scala-js/issues/3918) Mixed-in field in class inside lazy val rhs is erroneously immutable in the IR -> IR checking error
+* [#4511](https://github.com/scala-js/scala-js/issues/4511) Nested JS Class in JS Class with Scala companion crashes compiler
+* [#4465](https://github.com/scala-js/scala-js/issues/4465) Default parameters in constructors of nested JS classes cause invalid IR
+* [#4526](https://github.com/scala-js/scala-js/issues/4526) Compiler crashes on nested JS class with default constructor params with private companion
+* [#4469](https://github.com/scala-js/scala-js/issues/4469) Better error message when executing tests with Node missing
+* [#4336](https://github.com/scala-js/scala-js/issues/4336) Failing `<project>/run` can `close()` subsequent runs too early
+* [#105](https://github.com/scala-js/scala-js/issues/105) `String.split(x: Array[Char])` produces bad regexes
+
+You can find the full list [on GitHub](https://github.com/scala-js/scala-js/issues?q=is%3Aissue+milestone%3Av1.7.0+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 1.7.0
+* [1.7.0 scalajs-library]({{ site.production_url }}/api/scalajs-library/1.7.0/scala/scalajs/js/index.html)
+* [1.7.0 scalajs-test-interface]({{ site.production_url }}/api/scalajs-test-interface/1.7.0/)
+* [1.7.0 scalajs-ir]({{ site.production_url }}/api/scalajs-ir/1.7.0/org/scalajs/ir/index.html)
+* [1.7.0 scalajs-linker-interface]({{ site.production_url }}/api/scalajs-linker-interface/1.7.0/org/scalajs/linker/interface/index.html) ([Scala.js version]({{ site.production_url }}/api/scalajs-linker-interface-js/1.7.0/org/scalajs/linker/interface/index.html))
+* [1.7.0 scalajs-linker]({{ site.production_url }}/api/scalajs-linker/1.7.0/org/scalajs/linker/index.html) ([Scala.js version]({{ site.production_url }}/api/scalajs-linker-js/1.7.0/org/scalajs/linker/index.html))
+* [1.7.0 scalajs-test-adapter]({{ site.production_url }}/api/scalajs-sbt-test-adapter/1.7.0/org/scalajs/testing/adapter/index.html)
+* [1.7.0 sbt-scalajs]({{ site.production_url }}/api/sbt-scalajs/1.7.0/#org.scalajs.sbtplugin.package)
+
 ### 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/)

doc/internals/version-history.md

@@ -5,6 +5,7 @@ title: Version history
 
 ## Version history of Scala.js
 
+- [1.7.0](/news/2021/08/04/announcing-scalajs-1.7.0/)
 - [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/)