[Scala 3] Add annotation to derive all case class methods as graphql …

…fields (#2306)

core/src/main/scala-3/caliban/schema/AnnotationsVersionSpecific.scala

@@ -8,8 +8,17 @@ trait AnnotationsVersionSpecific {
    * Annotation that can be used on a case class method to mark it as a GraphQL field.
    * The method must be public, a `def` (does not work on `val`s / `lazy val`s) and must not take any arguments.
    *
-   * NOTE: This annotation is not safe for use with ahead-of-time compilation (e.g., generating a GraalVM native-image executable)
+   * '''NOTE''' This annotation is not safe for use with ahead-of-time compilation (e.g., generating a GraalVM native-image executable)
    */
   case class GQLField() extends StaticAnnotation
 
+  /**
+   * Annotation that can be used on a case class / case object to have all the public methods on it derived as fields.
+   *
+   * If you wish to exclude a public method from being derived as a field, you can annotate it with [[GQLExclude]].
+   *
+   * @see [[GQLField]] for a more fine-grained control over which methods are derived as fields
+   */
+  case class GQLFieldsFromMethods() extends StaticAnnotation
+
 }

core/src/main/scala-3/caliban/schema/macros/Macros.scala

@@ -28,14 +28,14 @@ object Macros {
     val annSymbol = TypeRepr.of[GQLExcluded].typeSymbol
     Expr(TypeRepr.of[Parent].typeSymbol.primaryConstructor.paramSymss.flatten.exists { v =>
       fieldName.map(_ == v.name).getOrElse(false)
-      && v.getAnnotation(annSymbol).isDefined
+      && v.hasAnnotation(annSymbol)
     })
   }
 
   private def hasAnnotationImpl[T: Type, Ann: Type](using qctx: Quotes): Expr[Boolean] = {
     import qctx.reflect.*
     val annSymbol = TypeRepr.of[Ann].typeSymbol
-    Expr(TypeRepr.of[T].typeSymbol.getAnnotation(annSymbol).isDefined)
+    Expr(TypeRepr.of[T].typeSymbol.hasAnnotation(annSymbol))
   }
 
   private def implicitExistsImpl[T: Type](using q: Quotes): Expr[Boolean] = {
@@ -53,11 +53,13 @@ object Macros {
 
   private def hasFieldsFromMethodsImpl[T: Type](using q: Quotes): Expr[Boolean] = {
     import q.reflect.*
-    val targetSym = TypeTree.of[T].symbol
-    val annType   = TypeRepr.of[GQLField]
-    val annSym    = annType.typeSymbol
+    val gqlFieldSym             = TypeRepr.of[GQLField].typeSymbol
+    val gqlFieldsFromMethodsSym = TypeRepr.of[GQLFieldsFromMethods].typeSymbol
 
-    Expr(targetSym.declaredMethods.exists(_.getAnnotation(annSym).isDefined))
+    Expr(
+      TypeRepr.of[T].typeSymbol.hasAnnotation(gqlFieldsFromMethodsSym)
+        || TypeTree.of[T].symbol.declaredMethods.exists(_.hasAnnotation(gqlFieldSym))
+    )
   }
 
   private def fieldsFromMethodsImpl[R: Type, T: Type](using
@@ -66,8 +68,12 @@ object Macros {
     import q.reflect.*
     val targetSym  = TypeTree.of[T].symbol
     val targetType = TypeRepr.of[T]
-    val annType    = TypeRepr.of[GQLField]
-    val annSym     = annType.typeSymbol
+
+    val gqlFieldAnnType = TypeRepr.of[GQLField]
+    val gqlFieldAnnSym  = gqlFieldAnnType.typeSymbol
+
+    val gqlExcludedAnnSym          = TypeRepr.of[GQLExcluded].typeSymbol
+    val gqlFieldsFromMethodsAnnSym = TypeRepr.of[GQLFieldsFromMethods].typeSymbol
 
     def summonSchema(methodSym: Symbol): Expr[Schema[R, ?]] = {
       val fieldType = targetType.memberType(methodSym)
@@ -91,29 +97,35 @@ object Macros {
     // Unfortunately we can't reuse Magnolias filtering so we copy the implementation
     def filterAnnotation(ann: Term): Boolean = {
       val tpe = ann.tpe
+      val sym = tpe.typeSymbol
 
-      tpe != annType && // No need to include the GQLField annotation
-      (tpe.typeSymbol.maybeOwner.isNoSymbol ||
-        (tpe.typeSymbol.owner.fullName != "scala.annotation.internal" &&
-          tpe.typeSymbol.owner.fullName != "jdk.internal"))
+      tpe != gqlFieldAnnType && // No need to include the GQLField annotation
+      (sym.maybeOwner.isNoSymbol ||
+        (sym.owner.fullName != "scala.annotation.internal" &&
+          sym.owner.fullName != "jdk.internal"))
     }
 
     def extractAnnotations(methodSym: Symbol): List[Expr[Any]] =
       methodSym.annotations.filter(filterAnnotation).map(_.asExpr.asInstanceOf[Expr[Any]])
 
     Expr.ofList {
-      targetSym.declaredMethods
-        .filter(_.getAnnotation(annSym).isDefined)
-        .map { method =>
-          checkMethodNoArgs(method)
-          '{
-            (
-              ${ Expr(method.name) },
-              ${ Expr.ofList(extractAnnotations(method)) },
-              ${ summonSchema(method) }
-            )
-          }
+      // NOTE: `Synthetic` methods are ones generated by the compiler, such as `copy`, `equals`, `hashCode`, etc.
+      val allMethods = targetSym.declaredMethods.filterNot(_.flags.is(Flags.Synthetic))
+      val filtered   =
+        if targetType.typeSymbol.hasAnnotation(gqlFieldsFromMethodsAnnSym)
+        then allMethods.filterNot(_.hasAnnotation(gqlExcludedAnnSym))
+        else allMethods.filter(_.hasAnnotation(gqlFieldAnnSym))
+
+      filtered.map { method =>
+        checkMethodNoArgs(method)
+        '{
+          (
+            ${ Expr(method.name) },
+            ${ Expr.ofList(extractAnnotations(method)) },
+            ${ summonSchema(method) }
+          )
         }
+      }
     }
   }
 

core/src/test/scala-3/caliban/schema/Scala3DerivesSpec.scala

@@ -2,7 +2,7 @@ package caliban.schema
 
 import caliban.*
 import caliban.parsing.adt.Directive
-import caliban.schema.Annotations.{ GQLDescription, GQLDirective, GQLField, GQLInterface, GQLName }
+import caliban.schema.Annotations.*
 import zio.test.{ assertTrue, ZIOSpecDefault }
 import zio.{ RIO, Task, ZIO }
 
@@ -281,6 +281,28 @@ object Scala3DerivesSpec extends ZIOSpecDefault {
                 |  barValue: Int!
                 |}""".stripMargin
 
+            assertTrue(rendered == expected)
+          },
+          test("annotation on case class directly") {
+            @GQLFieldsFromMethods
+            case class Foo(value: String) derives Schema.SemiAuto {
+              def fooValue: Option[String]   = None
+              def barValue: Int              = 42
+              @GQLExcluded def bazValue: Int = 42
+            }
+            val rendered = graphQL(RootResolver(Foo("foo"))).render
+
+            val expected =
+              """schema {
+                |  query: Foo
+                |}
+                |
+                |type Foo {
+                |  value: String!
+                |  fooValue: String
+                |  barValue: Int!
+                |}""".stripMargin
+
             assertTrue(rendered == expected)
           }
         )