From 5e5735b73d5006ab7d865f1756fb0b7063179a22 Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Wed, 28 Jun 2023 13:01:59 +0200
Subject: [PATCH] Test stdlib-bootstrpped ScalaNumericConversions.underlying

---
 project/TastyMiMaFilters.scala                |  4 ++-
 .../src/Main.scala                            | 30 +++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/project/TastyMiMaFilters.scala b/project/TastyMiMaFilters.scala
index 7a1fb0545f23..95eeb531958a 100644
--- a/project/TastyMiMaFilters.scala
+++ b/project/TastyMiMaFilters.scala
@@ -63,7 +63,9 @@ object TastyMiMaFilters {
     // Problem? Very complicated signature
     ProblemMatcher.make(ProblemKind.IncompatibleTypeChange, "scala.collection.generic.IsMap.mapOpsIsMap"),
 
-    // Problem: Overriding java method (`public abstract Object underlying();` with `def underlying: Object`)
+    // Probably OK: Overriding java method (`public abstract Object underlying();` with `def underlying: Object`)
+    // Calls to the underlying seem to link correctly.
+    // Tested in stdlib-bootstrapped/test/Main.scala
     ProblemMatcher.make(ProblemKind.MissingTermMember, "scala.math.Big*.underlying"),
     ProblemMatcher.make(ProblemKind.NewAbstractMember, "scala.math.ScalaNumericConversions.underlying"),
 
diff --git a/stdlib-bootstrapped-tasty-tests/src/Main.scala b/stdlib-bootstrapped-tasty-tests/src/Main.scala
index 1ac8203cbdeb..ca72be1e9248 100644
--- a/stdlib-bootstrapped-tasty-tests/src/Main.scala
+++ b/stdlib-bootstrapped-tasty-tests/src/Main.scala
@@ -16,6 +16,7 @@ object HelloWorld:
     testScala2UnapplySignatures()
     testScala2ObjectParents()
     testScala2CaseClassUnderscoreMembers()
+    testScalaNumberUnderlying()
   }
 
   def testScala2UnapplySignatures() = {
@@ -37,3 +38,32 @@ object HelloWorld:
     val some: Some[Int] = Some(1)
     // FIXME: assert(!typeChecks("some._1"))
   }
+
+  def testScalaNumberUnderlying() = {
+    import scala.math.{ScalaNumericConversions, ScalaNumber}
+
+    val _: java.math.BigInteger = BigInt(1).underlying
+    val _: Object = (BigInt(1): ScalaNumericConversions).underlying
+    val _: Object = (BigInt(1): ScalaNumber).underlying
+
+    // val _: java.math.BigDecimal = BigDecimal(1).underlying // FIXME: inferred result type of non-private method
+    val _: Object = (BigDecimal(1): ScalaNumericConversions).underlying
+    val _: Object = (BigDecimal(1): ScalaNumber).underlying
+
+    class MyNumber1(override val underlying: BigInt) extends ScalaNumericConversions {
+      def doubleValue: Double = ???; def floatValue: Float = ???;
+      def intValue: Int = ???; def longValue: Long = ???
+      def isWhole: Boolean = ???
+    }
+    val _: BigInt = MyNumber1(1).underlying
+    val _: Object = (MyNumber1(1): ScalaNumericConversions).underlying
+    val _: Object = (MyNumber1(1): ScalaNumber).underlying
+
+    class MyNumber2(override val underlying: Object) extends ScalaNumber {
+      def doubleValue: Double = ???; def floatValue: Float = ???;
+      def intValue: Int = ???; def longValue: Long = ???
+      def isWhole: Boolean = ???
+    }
+    val _: Object = MyNumber2(BigInt(1)).underlying
+    val _: Object = (MyNumber2(BigInt(1)): ScalaNumber).underlying
+  }