Refine dependency extraction: Ignore packages

We can ignore packages when collecting dependencies for incremental
compilation. We make sure not to ignore dependencies on package object.

Author: allanrenucci

.drone.yml

@@ -49,9 +49,9 @@ pipeline:
     commands:
       - cp -R . /tmp/4/ && cd /tmp/4/
       - ./project/scripts/sbt sbt-dotty/scripted
-    when:
-      # sbt scripted tests are slow and only run on nightly or deployment
-      event: [ tag, deployment ]
+    # when:
+    #   # sbt scripted tests are slow and only run on nightly or deployment
+    #   event: [ tag, deployment ]
 
   # DOCUMENTATION:
   documentation:

compiler/src/dotty/tools/dotc/sbt/ExtractDependencies.scala

@@ -315,7 +315,7 @@ private class ExtractDependenciesCollector extends tpd.TreeTraverser { thisTreeT
     !sym.exists ||
     sym.unforcedIsAbsent || // ignore dependencies that have a symbol but do not exist.
                             // e.g. java.lang.Object companion object
-    sym.is(PackageClass) ||
+    sym.is(Package) ||
     sym.isEffectiveRoot ||
     sym.isAnonymousFunction ||
     sym.isAnonymousClass

sbt-bridge/test/xsbt/DependencySpecification.scala

@@ -145,6 +145,25 @@ class DependencySpecification {
     assertEquals(Set("abc.A"), deps("H"))
   }
 
+  @Test
+  def extractedClassDependenciesOnPackageObject = {
+    val srcA = "package object foo { def bar = 1 }"
+    val srcB =
+      """|package foo
+         |
+         |class Test {
+         |  bar
+         |}
+      """.stripMargin
+
+    val compilerForTesting = new ScalaCompilerForUnitTesting
+    val classDependencies =
+      compilerForTesting.extractDependenciesFromSrcs(srcA, srcB)
+
+    val memberRef = classDependencies.memberRef
+    assertEquals(Set("foo.package"), memberRef("foo.Test"))
+  }
+
   private def extractClassDependenciesPublic: ExtractedClassDependencies = {
     val srcA = "class A"
     val srcB = "class B extends D[A]"

sbt-bridge/test/xsbt/ExtractUsedNamesSpecification.scala

@@ -275,6 +275,20 @@ class ExtractUsedNamesSpecification {
     assertEquals(Set(), findPatMatUsages(notUsedInPatternMatch))
   }
 
+  @Test
+  def extractedNamesInImport = {
+    val src =
+      """|import java.util.List
+         |
+         |class Test
+      """.stripMargin
+
+    val compilerForTesting = new ScalaCompilerForUnitTesting
+    val usedNames = compilerForTesting.extractUsedNamesFromSrc(src)
+
+    assertEquals(standardNames + "List", usedNames("Test"))
+  }
+
   /**
    * Standard names that appear in every compilation unit that has any class
    * definition.