Fixed fragment applicability to union types; no interfaces in unions

modules/core/src/main/scala/compiler.scala

@@ -1016,9 +1016,12 @@ object QueryCompiler {
  */
  def fragmentApplies(typeCond: NamedType, ctpe: NamedType): Boolean =
  (typeCond.dealias, ctpe.dealias) match {
- case (_: InterfaceType, u: UnionType) => u.members.forall(_ <:< typeCond)
- case (_, u: UnionType) => u.members.exists(typeCond <:< _)
- case _ => typeCond <:< ctpe || ctpe <:< typeCond
+ case (u: UnionType, _) =>
+ u.members.exists(m => fragmentApplies(m, ctpe))
+ case (_, u: UnionType) =>
+ u.members.exists(m => fragmentApplies(typeCond, m))
+ case _ =>
+ typeCond <:< ctpe || ctpe <:< typeCond
  }
 
  def elaborateBinding(b: Binding, vars: Vars): Elab[Binding] =

modules/core/src/main/scala/schema.scala

@@ -1749,7 +1749,7 @@ object SchemaValidator {
  case None => List(Problem(s"Undefined type '${member.name}' included in union '${tpe.name}'"))
  case Some(mtpe) =>
  mtpe match {
- case (_: ObjectType) | (_: InterfaceType) => Nil
+ case (_: ObjectType) => Nil
  case _ => List(Problem(s"Non-object type '${member.name}' included in union '${tpe.name}'"))
  }
  }

modules/core/src/test/scala/compiler/FragmentSuite.scala

@@ -561,6 +561,86 @@ final class FragmentSuite extends CatsEffectSuite {
  assertIO(res, List(expectedResult))
  }
 
+ test("typed union nested fragment query") {
+ val query = """
+ query FragmentUnionTyping {
+ user: user(id: "1") {
+ favourite {
+ __typename
+ ...userOrPageFragment
+ }
+ }
+ }
+
+ fragment userFragment on User {
+ id
+ name
+ }
+
+ fragment pageFragment on Page {
+ id
+ title
+ }
+
+ fragment userOrPageFragment on UserOrPage {
+ ...userFragment
+ ...pageFragment
+ }
+ """
+
+ val User = FragmentMapping.schema.ref("User")
+ val Page = FragmentMapping.schema.ref("Page")
+
+ val expected =
+ Select("user", None,
+ Unique(
+ Filter(Eql(FragmentMapping.UserType / "id", Const("1")),
+ Select("favourite", None,
+ Group(List(
+ Introspect(FragmentMapping.schema, Select("__typename", None, Empty)),
+ Narrow(
+ User,
+ Group(List(
+ Select("id", None, Empty),
+ Select("name", None, Empty)
+ ))
+ ),
+ Narrow(
+ Page,
+ Group(List(
+ Select("id", None, Empty),
+ Select("title", None, Empty)
+ ))
+ )
+ ))
+ )
+ )
+ )
+ )
+
+ val expectedResult = json"""
+ {
+ "data" : {
+ "user" : {
+ "favourite" : {
+ "__typename" : "User",
+ "id" : "2",
+ "name" : "Bob"
+ }
+ }
+ }
+ }
+ """
+
+ val compiled = FragmentMapping.compiler.compile(query)
+
+ assertEquals(compiled.map(_.query), Result.Success(expected))
+
+ val res = runOperation(compiled)
+
+ assertIO(res, List(expectedResult))
+ }
+
  test("supertype fragment query (1)") {
  val query = """
  query withFragments {

modules/core/src/test/scala/extensions/ExtensionsSuite.scala

@@ -399,7 +399,7 @@ final class ExtensionsSuite extends CatsEffectSuite {
  interface Interface {
  id: String!
  }
- union Union = Object | Interface
+ union Union = Object
  enum Enum { A, B, C }
  input Input { id: String! }
 

modules/core/src/test/scala/sdl/SDLSuite.scala

@@ -331,10 +331,13 @@ final class SDLSuite extends CatsEffectSuite {
  |interface Intrf {
  | bar: String
  |}
- |type Obj implements Intrf {
+ |type Obj1 implements Intrf {
  | bar: String
  |}
- |union Union = Intrf | Obj
+ |type Obj2 implements Intrf {
+ | bar: String
+ |}
+ |union Union = Obj1 | Obj2
  |enum Enum {
  | A
  | B
@@ -352,7 +355,11 @@ final class SDLSuite extends CatsEffectSuite {
  |extend interface Intrf @Intrf {
  | baz: Boolean
  |}
- |extend type Obj @Obj {
+ |extend type Obj1 @Obj {
+ | baz: Boolean
+ | quux: String
+ |}
+ |extend type Obj2 @Obj {
  | baz: Boolean
  | quux: String
  |}
@@ -378,7 +385,7 @@ final class SDLSuite extends CatsEffectSuite {
  assertEquals(ser, schema.success)
  }
 
- test("round-trip extensions (no fields or members") {
+ test("round-trip extensions (no fields or members)") {
  val schema =
  """|schema {
  | query: MyQuery
@@ -390,10 +397,13 @@ final class SDLSuite extends CatsEffectSuite {
  |interface Intrf {
  | bar: String
  |}
- |type Obj implements Intrf {
+ |type Obj1 implements Intrf {
+ | bar: String
+ |}
+ |type Obj2 implements Intrf {
  | bar: String
  |}
- |union Union = Intrf | Obj
+ |union Union = Obj1 | Obj2
  |enum Enum {
  | A
  | B
@@ -404,7 +414,8 @@ final class SDLSuite extends CatsEffectSuite {
  |extend schema @Sch
  |extend scalar Scalar @Sca
  |extend interface Intrf @Intrf
- |extend type Obj @Obj
+ |extend type Obj1 @Obj
+ |extend type Obj2 @Obj
  |extend union Union @Uni
  |extend enum Enum @Enu
  |extend input Input @Inp