Advance the support for Scala.js

[sjrd]

Dotty contains preliminary support for Scala.js under the flag -scalajs. Or rather, it contains the infrastructure for preliminary support. It is far from being actually usable, but this is where you can help!

I have written a tutorial that walks you through a few steps that you can do to further the support of Scala.js in Dotty. Even if you do not typically contribute to a compiler, this can be your chance. It is not very difficult, given that there already exists an extensive test suite, as well as a working implementation for scalac.

Read the tutorial, and get going!

[cquiroz]

I noted that often when adding and then removing a test suite I'd get errors like it was still trying to compile the removed test suite

I solved it by explicitly deleting the files with
rm -Rf tests/out/bootstrap/sjsJUnitTests

[neshkeev]

The following two tests from javalib.lang fail without dotty alteration (the rest of the tests from the package are added in #7255):

1. javalib/lang/ClassTest.scala: error log link
2. javalib/lang/StringTest.scala: error log link

[neshkeev]

The following tests from javalib.io fail without dotty alteration (only three tests from javalib.io are successful so far #7271)

1. javalib/io/ByteArrayInputStreamTest.scala: error log link
2. javalib/io/ByteArrayOutputStreamTest.scala: error log link
3. javalib/io/DataInputStreamTest.scala: error log link
4. javalib/io/DataOutputStreamTest.scala: error log link
5. javalib/io/InputStreamTest.scala: error log link
6. javalib/io/OutputStreamWriterTest.scala: error log link
7. javalib/io/PrintStreamTest.scala: error log link
8. javalib/io/ReadersTest.scala: error log link

[neshkeev]

All the tests from javalib.math have been enabled, no failing tests were discovered #7272

[neshkeev]

The following test from the javalib.net fails:

1. javalib/net/URITest.scala: error log link

The second test in the group javalib/net/URLDecoderTest.scala has been enabled #7273

[Lacaranian]

I may dig into that URITest failure.

Edit: Looking at some of the other failures as well.

[neshkeev]

@Lacaranian , good, please do it