Scala: Detect consumed symbols in self-type annotations

docs/notes/2.22.x.md

@@ -56,6 +56,8 @@ deploy jars, in addition to those specified on a per-jar basis in the `deploy_ja
 This option's default value excludes signature files from constituent jars, which are known to cause the deploy jar
 to fail to execute (since naturally it doesn't match those signatures).
 
+Scala dependency inference used to ignore self-type annotations, which led to not being able to detect dependencies between files in the same package where self-type annotations were used. Moving forward if self-type annotations are being used and no import present for the given type, it will be assumed the referenced type is defined in the same package.
+
 Also reduced verbosity of log messages for the internal Nailgun server instances used for running or compiling code
 replacing it by a single message informing about the size of the Nailgun pool. Previous log messages are still
 emitted at debug log level.

src/python/pants/backend/scala/dependency_inference/ScalaParser.scala

@@ -185,6 +185,7 @@ class SourceAnalysisTraverser extends Traverser {
     withNamePart(
       name,
       () => {
+        apply(templ.self)
         apply(templ.early)
         apply(templ.stats)
       }
@@ -383,6 +384,9 @@ class SourceAnalysisTraverser extends Traverser {
       init.argss.foreach(arg => apply(arg))
     }
 
+    case Self(_name, Some(decltpe)) =>
+      extractNamesFromTypeTree(decltpe).foreach(recordConsumedSymbol(_))
+
     case node @ Term.Select(_, _) => {
       val name = extractName(node)
       recordConsumedSymbol(name)

src/python/pants/backend/scala/dependency_inference/scala_parser_test.py

@@ -735,3 +735,21 @@ def doSomething[F[_] : Applicative]() = ()
         "foo.Applicative",
         "foo.Functor",
     ]
+
+
+def test_self_types_on_same_package(rule_runner: RuleRunner) -> None:
+    analysis = _analyze(
+        rule_runner,
+        textwrap.dedent(
+            """\
+            package foo
+
+            trait Bar { self: Foo =>
+            }
+            """
+        ),
+    )
+
+    assert sorted(analysis.fully_qualified_consumed_symbols()) == [
+        "foo.Foo",
+    ]