[Scala 3] restore SimpleClassName.materialize

MIGRATION.md

@@ -172,7 +172,6 @@ Full per-file list with locations is in the Backlog table below (filter rows whe
 | `core/src/main/scala/com/avsystem/commons/misc/SealedUtils.scala:8`                               | caseObjectsFor (Scala 2 macro def)                                                                    | L      |
 | `core/src/main/scala/com/avsystem/commons/misc/SelfInstance.scala:4`                              | C[_] existential narrowed to C[Any] (Scala 3 forbids HKT wildcard application)                        | S      |
 | `core/src/main/scala/com/avsystem/commons/misc/SelfInstance.scala:7`                              | SelfInstance.materialize (Scala 2 macro def)                                                          | L      |
-| `core/src/main/scala/com/avsystem/commons/misc/SimpleClassName.scala:8`                           | SimpleClassName.materialize (Scala 2 macro def)                                                       | L      |
 | `core/src/main/scala/com/avsystem/commons/misc/SourceInfo.scala:28`                               | SourceInfo.here (Scala 2 macro def)                                                                   | L      |
 | `core/src/main/scala/com/avsystem/commons/misc/Timestamp.scala:13`                                | Comparable[Timestamp] (Scala 3 forbids AnyVal inheriting Object-derived traits)                       | S      |
 | `core/src/main/scala/com/avsystem/commons/misc/TypeString.scala:31`                               | TypeString.materialize (Scala 2 macro def)                                                            | L      |

core/src/main/scala/com/avsystem/commons/misc/SimpleClassName.scala

@@ -1,10 +1,18 @@
 package com.avsystem.commons
 package misc
 
+import scala.quoted.*
+
 case class SimpleClassName[T](name: String) extends AnyVal
 object SimpleClassName {
   def of[T](implicit scn: SimpleClassName[T]): String = scn.name
 
-  // TODO[scala3-port]: SimpleClassName.materialize (Scala 2 macro def) (L)
-  implicit def materialize[T]: SimpleClassName[T] = ???
+  inline implicit def materialize[T]: SimpleClassName[T] = ${ materializeImpl[T] }
+
+  private def materializeImpl[T: Type](using Quotes): Expr[SimpleClassName[T]] = {
+    import quotes.reflect.*
+    val sym = TypeRepr.of[T].dealias.typeSymbol
+    val name = Expr(sym.name.stripSuffix("$"))
+    '{ SimpleClassName[T]($name) }
+  }
 }

core/src/test/scala/com/avsystem/commons/misc/SimpleClassNameTest.scala

@@ -0,0 +1,21 @@
+package com.avsystem.commons.misc
+
+import org.scalatest.funsuite.AnyFunSuite
+
+class SimpleClassNameTest extends AnyFunSuite {
+  test("String") {
+    assert(SimpleClassName.of[String] == "String")
+  }
+
+  test("List[Int]") {
+    assert(SimpleClassName.of[List[Int]] == "List")
+  }
+
+  test("nested case class") {
+    assert(SimpleClassName.of[SimpleClassNameTest.Foo] == "Foo")
+  }
+}
+
+object SimpleClassNameTest {
+  case class Foo(x: Int)
+}