[CI] Restore compilation and tests of scaladoc (#24779)

The `scaladoc` project has not been compiled or tested recently. 
- Restore CI checks for scaladoc 
- Fixes compilation under -Yexplicit-nulls 
- Adjust tests for the new classpath without Scala 2 stdlib: 
- Remove `Scaladoc2LegacyExternalLocationProviderIntegrationTest` cannot
be tested without any Scala 2 library on classpath.
- Change order of `ExternalMappings` - previously it picked Scala 2
first (`.*scala/.*:`), then `.*externalStubs.*` - it no longer matches
becouse first filter was applied only to Scala2 stdlib, but not to the
Scala 3 stdlib additions. Switching order makes the 2 tests pass again
- `project/scripts/cmdScaladocTests` removed dead logic towards Scala 2
stdlib

Author: WojciechMazur

.github/workflows/scaladoc.yaml

@@ -41,11 +41,11 @@ jobs:
       - name: Compile and test scala3doc-js
         run: ./project/scripts/sbt scaladoc-js-main/test
 
-      #- name: Compile and test
-      #  run: |
-      #    ./project/scripts/sbt scaladoc/test
-      #    ./project/scripts/sbt dist/Universal/stage
-      #    ./project/scripts/cmdScaladocTests
+      - name: Compile and test
+       run: |
+         ./project/scripts/sbt scaladoc/test
+         ./project/scripts/sbt dist/Universal/stage
+         ./project/scripts/cmdScaladocTests
 
       - name: Locally publish self
         run: ./project/scripts/sbt scaladoc/publishLocal

project/scripts/cmdScaladocTests

@@ -7,9 +7,6 @@ clear_out "$OUT"
 clear_out "$OUT1"
 
 
-STDLIB_COMMAND="$SBT \"eval println(Build.stdlibVersion(Modes.NonBootstrapped))\""
-STDLIB_VERSION=$(eval $STDLIB_COMMAND | tail -n 2 | head -n 1)
-
 DOTTY_NONBOOTSTRAPPED_VERSION_COMMAND="$SBT \"eval println(Build.dottyNonBootstrappedVersion)\""
 DOTTY_NONBOOTSTRAPPED_VERSION=$(eval $DOTTY_NONBOOTSTRAPPED_VERSION_COMMAND | tail -n 2 | head -n 1)
 
@@ -23,8 +20,6 @@ SOURCE_LINKS_VERSION="${GITHUB_SHA:-$DOTTY_BOOTSTRAPPED_VERSION}"
 dist/target/universal/stage/bin/scaladoc \
   -d "$OUT1" \
   -project "scaladoc testcases" \
-  -source-links:out/bootstrap/scala2-library-bootstrapped/scala-"${DOTTY_NONBOOTSTRAPPED_VERSION}"/src_managed/main/scala-library-src=github://scala/scala/v"${STDLIB_VERSION}"#src/library \
-  -source-links:out/bootstrap/scala2-library-bootstrapped/scala-"${DOTTY_NONBOOTSTRAPPED_VERSION}"/src_managed/main/dotty-library-src=github://"${SOURCE_LINKS_REPOSITORY}"/"${SOURCE_LINKS_VERSION}"\#library/src \
   -source-links:github://"${SOURCE_LINKS_REPOSITORY}"/"${SOURCE_LINKS_VERSION}" \
   "-external-mappings:.*scala/.*::scaladoc3::https://dotty.epfl.ch/api/,.*java/.*::javadoc::https://docs.oracle.com/javase/8/docs/api/" \
   "-skip-by-regex:.+\.internal($|\..+)" \

scaladoc/test/dotty/tools/scaladoc/BaseHtmlTest.scala

@@ -39,7 +39,7 @@ class BaseHtmlTest:
         projectVersion = Some(projectVersion)
       ))
       Scaladoc.run(args)(using testContext)
-      op(using ProjectContext(args.output.toPath))
+      op(using ProjectContext(args.output.nn.toPath))
 
     finally IO.delete(dest)
   end withGeneratedDoc

scaladoc/test/dotty/tools/scaladoc/ExternalLocationProviderIntegrationTest.scala

@@ -1,8 +1,6 @@
 package dotty.tools.scaladoc
 
-import scala.io.Source
 import scala.jdk.CollectionConverters._
-import scala.util.matching.Regex
 import dotty.tools.scaladoc.test.BuildInfo
 import java.nio.file.Path;
 import org.jsoup.Jsoup
@@ -26,8 +24,8 @@ class JavadocExternalLocationProviderIntegrationTest extends ExternalLocationPro
 class Scaladoc2ExternalLocationProviderIntegrationTest extends ExternalLocationProviderIntegrationTest(
   "externalScaladoc2",
   List(
+    ".*externalStubs.*::scaladoc2::https://external.stubs/api/",
     ".*scala/.*::scaladoc2::https://www.scala-lang.org/api/current/",
-    ".*externalStubs.*::scaladoc2::https://external.stubs/api/"
   ),
   List(
     "https://www.scala-lang.org/api/current/scala/util/matching/Regex$$Match.html",
@@ -43,8 +41,8 @@ class Scaladoc2ExternalLocationProviderIntegrationTest extends ExternalLocationP
 class Scaladoc3ExternalLocationProviderIntegrationTest extends ExternalLocationProviderIntegrationTest(
   "externalScaladoc3",
   List(
+    ".*externalStubs.*::scaladoc3::https://external.stubs/api/",
     ".*scala/.*::scaladoc3::https://dotty.epfl.ch/api/",
-    ".*externalStubs.*::scaladoc3::https://external.stubs/api/"
   ),
   List(
     "https://dotty.epfl.ch/api/scala/collection/immutable/Map.html",
@@ -55,26 +53,6 @@ class Scaladoc3ExternalLocationProviderIntegrationTest extends ExternalLocationP
   )
 )
 
-def getScalaLibraryPath: String = {
-  val classpath: List[String] = System.getProperty("java.class.path").split(java.io.File.pathSeparatorChar).toList
-  // For an unclear reason, depending on if we pass the compiler context onto the tasty inspector
-  // the scala-2-library path needs to have its characters case fixed with new java.io.File(stdlib).getCanonicalPath()
-  classpath.find(_.contains("scala-library-2")).getOrElse("foobarbazz") // If we don't find the scala 2 library, the test will fail
-}
-
-class Scaladoc2LegacyExternalLocationProviderIntegrationTest extends LegacyExternalLocationProviderIntegrationTest(
-  "externalScaladoc2",
-  List(s"${getScalaLibraryPath}#https://www.scala-lang.org/api/current/"),
-  List(
-    "https://www.scala-lang.org/api/current/scala/util/matching/Regex$$Match.html",
-    "https://www.scala-lang.org/api/current/scala/Predef$.html#String",
-    "https://www.scala-lang.org/api/current/scala/collection/immutable/Map.html",
-    "https://www.scala-lang.org/api/current/scala/collection/IterableOnceOps.html#addString(b:StringBuilder,start:String,sep:String,end:String):b.type",
-    "https://www.scala-lang.org/api/current/scala/collection/IterableOnceOps.html#mkString(start:String,sep:String,end:String):String"
-  )
-)
-
-
 abstract class ExternalLocationProviderIntegrationTest(
   name: String,
   mappings: Seq[String],
@@ -89,7 +67,7 @@ abstract class ExternalLocationProviderIntegrationTest(
   )
 
   override def runTest = afterRendering {
-    val output = summon[DocContext].args.output.toPath
+    val output = summon[DocContext].args.output.nn.toPath
     val linksBuilder = List.newBuilder[String]
 
     def processFile(path: Path): Unit =
@@ -113,17 +91,3 @@ abstract class ExternalLocationProviderIntegrationTest(
       reportError(reportMessage)
     }
   } :: Nil
-
-abstract class LegacyExternalLocationProviderIntegrationTest(
-  name: String,
-  mappings: Seq[String],
-  expectedLinks: Seq[String]
-) extends ExternalLocationProviderIntegrationTest(name, mappings, expectedLinks):
-
-  override def args = super.args.copy(
-      externalMappings = mappings.flatMap( s =>
-        ExternalDocLink.parseLegacy(s).fold(left => None, right => Some(right)
-      )
-    ).toList
-  )
-

scaladoc/test/dotty/tools/scaladoc/signatures/SignatureTest.scala

@@ -87,7 +87,7 @@ abstract class SignatureTest(
       kindMatch <- kinds.flatMap(k =>s"\\b$k\\b".r.findFirstMatchIn(signature)).headOption
       kind <- Option(kindMatch.group(0)) // to filter out nulls
       afterKind <- Option(kindMatch.after(0)) // to filter out nulls
-      name <- if kind.contains("extension") then Some(signature) // The name of an extension will always be the signature itself
+      case name: String <- if kind.contains("extension") then Some(signature) // The name of an extension will always be the signature itself
                     else identifierRegex.findFirstMatchIn(afterKind).map(_.group(1))
     yield name
 
@@ -97,8 +97,8 @@ abstract class SignatureTest(
       .filterNot(l => l.startWithAnyOfThese("=",":","{","}", "//") && !l.startsWith("//expected:"))
       .toSeq
       .flatMap {
-        case unexpectedRegex(signature) => findName(signature, kinds).map(Unexpected(_))
-        case expectedRegex(signature) => findName(signature, kinds).map(Expected(_, signature))
+        case unexpectedRegex(signature: String) => findName(signature, kinds).map(Unexpected(_))
+        case expectedRegex(signature: String) => findName(signature, kinds).map(Expected(_, signature))
         case signature =>
           findName(signature, kinds).map(
             Expected(_, commentRegex.replaceAllIn(signature, "")
@@ -107,7 +107,7 @@ abstract class SignatureTest(
       }
 
   private def signaturesFromDocumentation()(using DocContext): Seq[String] =
-    val output = summon[DocContext].args.output.toPath
+    val output = summon[DocContext].args.output.nn.toPath
     val signatures = List.newBuilder[String]
 
     def processFile(path: Path): Unit = if filterFunc(path) then

scaladoc/test/dotty/tools/scaladoc/snippets/SnippetsE2eTest.scala

@@ -146,16 +146,16 @@ object SnippetsE2eTest:
   case class Message(level: MessageLevel, offset: Offset)
   object SnippetInfo:
     def apply(str: String): SnippetInfo = str match {
-      case snippetInfoRegex(ol, oc, il, ic) => SnippetInfo(
+      case snippetInfoRegex(ol: String, oc: String, il: String, ic: String) => SnippetInfo(
         Offset(ol.toInt, oc.toInt),
         Offset(il.toInt, ic.toInt)
       )
     }
 
   object Message:
     def apply(str: String): Message = str match {
-      case errorRegex(ln, cl) => Message(MessageLevel.Error, Offset(ln.toInt, cl.toInt))
-      case warningRegex(ln, cl) => Message(MessageLevel.Warning, Offset(ln.toInt, cl.toInt))
+      case errorRegex(ln: String, cl: String) => Message(MessageLevel.Error, Offset(ln.toInt, cl.toInt))
+      case warningRegex(ln: String, cl: String) => Message(MessageLevel.Warning, Offset(ln.toInt, cl.toInt))
     }
   val snippetInfoRegex = (raw"SNIPPET\(" +
     raw"OUTERLINEOFFSET:(\d+),OUTERCOLUMNOFFSET:(\d+)," +