handle inlined tree in implicit parameter inlay hints

Author: zielinsky

presentation-compiler/src/main/dotty/tools/pc/PcInlayHintsProvider.scala

@@ -277,14 +277,18 @@ object ImplicitParameters:
   def unapply(tree: Tree)(using params: InlayHintsParams, ctx: Context) =
     if (params.implicitParameters()) {
       tree match
-        case Apply(fun, args)
-            if args.exists(isSyntheticArg) && !tree.sourcePos.span.isZeroExtent && !args.exists(isQuotes(_)) =>
-          val (implicitArgs, providedArgs) = args.partition(isSyntheticArg)
-          val pos = implicitArgs.head.sourcePos
-          Some(implicitArgs, pos)
+        case Apply(_, args) if hasImplicitArgs(tree, args) => implicitArgs(args)
+        case Inlined(Apply(_, args), _, _) if hasImplicitArgs(tree, args) => implicitArgs(args)
         case _ => None
     } else None
 
+  private def hasImplicitArgs(tree: Tree, args: List[Tree])(using Context): Boolean =
+    args.exists(isSyntheticArg) && !tree.sourcePos.span.isZeroExtent && !args.exists(isQuotes)
+
+  private def implicitArgs(args: List[Tree])(using Context): Option[(List[Tree], SourcePosition)] =
+    val found = args.filter(isSyntheticArg)
+    Option.when(found.nonEmpty)(found, found.head.sourcePos)
+
   @tailrec
   def isSyntheticArg(tree: Tree)(using Context): Boolean = tree match
     case tree: Ident =>

presentation-compiler/test/dotty/tools/pc/tests/inlayHints/InlayHintsSuite.scala

@@ -1723,4 +1723,38 @@ class InlayHintsSuite extends BaseInlayHintsSuite {
          |    .sum/*[BigDecimal<<scala/math/BigDecimal#>>]*//*(using BigDecimalIsFractional<<scala/math/Numeric.BigDecimalIsFractional.>>)*//*                           : BigDecimal<<scala/math/BigDecimal#>>*/
          |""".stripMargin
     )
+
+  @Test def `inline-def-implicit-param` =
+    check(
+     """|trait Codec[T]
+        |object Main {
+        |  given intCodec: Codec[Int] = ???
+        |  val x = summon[Codec[Int]]
+        |}
+        |""".stripMargin,
+     """|trait Codec[T]
+        |object Main {
+        |  given intCodec: Codec[Int] = ???
+        |  val x/*: Codec<<(1:6)>>[Int<<scala/Int#>>]*/ = summon[Codec[Int]]/*(using intCodec<<(3:8)>>)*/
+        |}
+        |""".stripMargin
+    )
+
+  @Test def `inline-def-implicit-param-vs-implicitly` =
+    check(
+     """|trait Codec[T]
+        |object Main {
+        |  implicit val intCodec: Codec[Int] = ???
+        |  val x = implicitly[Codec[Int]]
+        |  val y = summon[Codec[Int]]
+        |}
+        |""".stripMargin,
+     """|trait Codec[T]
+        |object Main {
+        |  implicit val intCodec: Codec[Int] = ???
+        |  val x/*: Codec<<(1:6)>>[Int<<scala/Int#>>]*/ = implicitly[Codec[Int]]/*(using intCodec<<(3:15)>>)*/
+        |  val y/*: Codec<<(1:6)>>[Int<<scala/Int#>>]*/ = summon[Codec[Int]]/*(using intCodec<<(3:15)>>)*/
+        |}
+        |""".stripMargin
+    )
 }