Add a test case for interfaces implementing other interfaces (#2851)

* add a test case for interfaces implementing other interfaces

* complexify the test a little bit to test possibelTypes

* fix writing interfaces implemented by interfaces

apollo-compiler/src/main/kotlin/com/apollographql/apollo/compiler/frontend/gql.kt

@@ -184,7 +184,11 @@ data class GQLInterfaceTypeDefinition(
   override fun write(bufferedSink: BufferedSink) {
     with(bufferedSink) {
       if (description != null) writeUtf8("\"\"\"${GraphQLString.encodeTripleQuoted(description)}\"\"\"\n")
-      writeUtf8("interface $name ${implementsInterfaces.joinToString(" ")}")
+      writeUtf8("interface $name")
+      if (implementsInterfaces.isNotEmpty()) {
+        writeUtf8(" implements ")
+        writeUtf8(implementsInterfaces.joinToString(" "))
+      }
       if (directives.isNotEmpty()) {
         writeUtf8(" ")
         directives.join(bufferedSink)

apollo-compiler/src/main/kotlin/com/apollographql/apollo/compiler/frontend/gqltypedefinition.kt

@@ -25,3 +25,4 @@ internal fun GQLTypeDefinition.possibleTypes(typeDefinitions: Map<String, GQLTyp
     }
   }
 }
+

apollo-compiler/src/test/graphql/com/example/interface_on_interface/GetHuman.kt

@@ -0,0 +1,93 @@
+// AUTO-GENERATED FILE. DO NOT MODIFY.
+//
+// This class was automatically generated by Apollo GraphQL plugin from the GraphQL queries it found.
+// It should not be modified by hand.
+//
+package com.example.interface_on_interface
+
+import com.apollographql.apollo.api.Operation
+import com.apollographql.apollo.api.OperationName
+import com.apollographql.apollo.api.Query
+import com.apollographql.apollo.api.internal.QueryDocumentMinifier
+import com.apollographql.apollo.api.internal.ResponseAdapter
+import com.example.interface_on_interface.adapter.GetHuman_ResponseAdapter
+import kotlin.Double
+import kotlin.String
+import kotlin.Suppress
+
+@Suppress("NAME_SHADOWING", "UNUSED_ANONYMOUS_PARAMETER", "LocalVariableName",
+    "RemoveExplicitTypeArguments", "NestedLambdaShadowedImplicitParameter", "PropertyName",
+    "RemoveRedundantQualifierName")
+class GetHuman : Query<GetHuman.Data> {
+  override fun operationId(): String = OPERATION_ID
+
+  override fun queryDocument(): String = QUERY_DOCUMENT
+
+  override fun variables(): Operation.Variables = Operation.EMPTY_VARIABLES
+
+  override fun name(): OperationName = OPERATION_NAME
+
+  override fun adapter(): ResponseAdapter<Data> = GetHuman_ResponseAdapter
+  data class Data(
+    val human: Human,
+    val node: Node
+  ) : Operation.Data {
+    data class Human(
+      val id: String,
+      val name: String,
+      val height: Double
+    )
+
+    interface Node {
+      val __typename: String
+
+      interface Human : Node {
+        override val __typename: String
+
+        val height: Double
+      }
+
+      data class HumanNode(
+        override val __typename: String,
+        override val height: Double
+      ) : Node, Human
+
+      data class OtherNode(
+        override val __typename: String
+      ) : Node
+
+      companion object {
+        fun Node.asHuman(): Human? = this as? Human
+      }
+    }
+  }
+
+  companion object {
+    const val OPERATION_ID: String =
+        "b5ec6431463438b91c2cf1c33eb4b6a1f9e2580b51fcf5150ef3685b9108a12c"
+
+    val QUERY_DOCUMENT: String = QueryDocumentMinifier.minify(
+          """
+          |query GetHuman {
+          |  human {
+          |    id
+          |    name
+          |    height
+          |  }
+          |  node {
+          |    __typename
+          |    ... on Human {
+          |      height
+          |    }
+          |  }
+          |}
+          """.trimMargin()
+        )
+
+    val OPERATION_NAME: OperationName = object : OperationName {
+      override fun name(): String {
+        return "GetHuman"
+      }
+    }
+  }
+}

apollo-compiler/src/test/graphql/com/example/interface_on_interface/TestOperation.graphql

@@ -0,0 +1,12 @@
+query GetHuman {
+  human {
+    id
+    name
+    height
+  }
+  node {
+    ... on Human {
+      height
+    }
+  }
+}

apollo-compiler/src/test/graphql/com/example/interface_on_interface/adapter/GetHuman_ResponseAdapter.kt

@@ -0,0 +1,185 @@
+// AUTO-GENERATED FILE. DO NOT MODIFY.
+//
+// This class was automatically generated by Apollo GraphQL plugin from the GraphQL queries it found.
+// It should not be modified by hand.
+//
+package com.example.interface_on_interface.adapter
+
+import com.apollographql.apollo.api.ResponseField
+import com.apollographql.apollo.api.internal.ResponseAdapter
+import com.apollographql.apollo.api.internal.ResponseReader
+import com.apollographql.apollo.api.internal.ResponseWriter
+import com.example.interface_on_interface.GetHuman
+import kotlin.Array
+import kotlin.Double
+import kotlin.String
+import kotlin.Suppress
+
+@Suppress("NAME_SHADOWING", "UNUSED_ANONYMOUS_PARAMETER", "LocalVariableName",
+    "RemoveExplicitTypeArguments", "NestedLambdaShadowedImplicitParameter", "PropertyName",
+    "RemoveRedundantQualifierName")
+object GetHuman_ResponseAdapter : ResponseAdapter<GetHuman.Data> {
+  private val RESPONSE_FIELDS: Array<ResponseField> = arrayOf(
+    ResponseField.forObject("human", "human", null, false, null),
+    ResponseField.forObject("node", "node", null, false, null)
+  )
+
+  override fun fromResponse(reader: ResponseReader, __typename: String?): GetHuman.Data {
+    return Data.fromResponse(reader, __typename)
+  }
+
+  override fun toResponse(writer: ResponseWriter, value: GetHuman.Data) {
+    Data.toResponse(writer, value)
+  }
+
+  object Data : ResponseAdapter<GetHuman.Data> {
+    private val RESPONSE_FIELDS: Array<ResponseField> = arrayOf(
+      ResponseField.forObject("human", "human", null, false, null),
+      ResponseField.forObject("node", "node", null, false, null)
+    )
+
+    override fun fromResponse(reader: ResponseReader, __typename: String?): GetHuman.Data {
+      return reader.run {
+        var human: GetHuman.Data.Human? = null
+        var node: GetHuman.Data.Node? = null
+        while(true) {
+          when (selectField(RESPONSE_FIELDS)) {
+            0 -> human = readObject<GetHuman.Data.Human>(RESPONSE_FIELDS[0]) { reader ->
+              Human.fromResponse(reader)
+            }
+            1 -> node = readObject<GetHuman.Data.Node>(RESPONSE_FIELDS[1]) { reader ->
+              Node.fromResponse(reader)
+            }
+            else -> break
+          }
+        }
+        GetHuman.Data(
+          human = human!!,
+          node = node!!
+        )
+      }
+    }
+
+    override fun toResponse(writer: ResponseWriter, value: GetHuman.Data) {
+      writer.writeObject(RESPONSE_FIELDS[0]) { writer ->
+        Human.toResponse(writer, value.human)
+      }
+      writer.writeObject(RESPONSE_FIELDS[1]) { writer ->
+        Node.toResponse(writer, value.node)
+      }
+    }
+
+    object Human : ResponseAdapter<GetHuman.Data.Human> {
+      private val RESPONSE_FIELDS: Array<ResponseField> = arrayOf(
+        ResponseField.forString("id", "id", null, false, null),
+        ResponseField.forString("name", "name", null, false, null),
+        ResponseField.forDouble("height", "height", null, false, null)
+      )
+
+      override fun fromResponse(reader: ResponseReader, __typename: String?): GetHuman.Data.Human {
+        return reader.run {
+          var id: String? = null
+          var name: String? = null
+          var height: Double? = null
+          while(true) {
+            when (selectField(RESPONSE_FIELDS)) {
+              0 -> id = readString(RESPONSE_FIELDS[0])
+              1 -> name = readString(RESPONSE_FIELDS[1])
+              2 -> height = readDouble(RESPONSE_FIELDS[2])
+              else -> break
+            }
+          }
+          GetHuman.Data.Human(
+            id = id!!,
+            name = name!!,
+            height = height!!
+          )
+        }
+      }
+
+      override fun toResponse(writer: ResponseWriter, value: GetHuman.Data.Human) {
+        writer.writeString(RESPONSE_FIELDS[0], value.id)
+        writer.writeString(RESPONSE_FIELDS[1], value.name)
+        writer.writeDouble(RESPONSE_FIELDS[2], value.height)
+      }
+    }
+
+    object Node : ResponseAdapter<GetHuman.Data.Node> {
+      private val RESPONSE_FIELDS: Array<ResponseField> = arrayOf(
+        ResponseField.forString("__typename", "__typename", null, false, null)
+      )
+
+      override fun fromResponse(reader: ResponseReader, __typename: String?): GetHuman.Data.Node {
+        val typename = __typename ?: reader.readString(RESPONSE_FIELDS[0])
+        return when(typename) {
+          "Human" -> HumanNode.fromResponse(reader, typename)
+          else -> OtherNode.fromResponse(reader, typename)
+        }
+      }
+
+      override fun toResponse(writer: ResponseWriter, value: GetHuman.Data.Node) {
+        when(value) {
+          is GetHuman.Data.Node.HumanNode -> HumanNode.toResponse(writer, value)
+          is GetHuman.Data.Node.OtherNode -> OtherNode.toResponse(writer, value)
+        }
+      }
+
+      object HumanNode : ResponseAdapter<GetHuman.Data.Node.HumanNode> {
+        private val RESPONSE_FIELDS: Array<ResponseField> = arrayOf(
+          ResponseField.forString("__typename", "__typename", null, false, null),
+          ResponseField.forDouble("height", "height", null, false, null)
+        )
+
+        override fun fromResponse(reader: ResponseReader, __typename: String?):
+            GetHuman.Data.Node.HumanNode {
+          return reader.run {
+            var __typename: String? = __typename
+            var height: Double? = null
+            while(true) {
+              when (selectField(RESPONSE_FIELDS)) {
+                0 -> __typename = readString(RESPONSE_FIELDS[0])
+                1 -> height = readDouble(RESPONSE_FIELDS[1])
+                else -> break
+              }
+            }
+            GetHuman.Data.Node.HumanNode(
+              __typename = __typename!!,
+              height = height!!
+            )
+          }
+        }
+
+        override fun toResponse(writer: ResponseWriter, value: GetHuman.Data.Node.HumanNode) {
+          writer.writeString(RESPONSE_FIELDS[0], value.__typename)
+          writer.writeDouble(RESPONSE_FIELDS[1], value.height)
+        }
+      }
+
+      object OtherNode : ResponseAdapter<GetHuman.Data.Node.OtherNode> {
+        private val RESPONSE_FIELDS: Array<ResponseField> = arrayOf(
+          ResponseField.forString("__typename", "__typename", null, false, null)
+        )
+
+        override fun fromResponse(reader: ResponseReader, __typename: String?):
+            GetHuman.Data.Node.OtherNode {
+          return reader.run {
+            var __typename: String? = __typename
+            while(true) {
+              when (selectField(RESPONSE_FIELDS)) {
+                0 -> __typename = readString(RESPONSE_FIELDS[0])
+                else -> break
+              }
+            }
+            GetHuman.Data.Node.OtherNode(
+              __typename = __typename!!
+            )
+          }
+        }
+
+        override fun toResponse(writer: ResponseWriter, value: GetHuman.Data.Node.OtherNode) {
+          writer.writeString(RESPONSE_FIELDS[0], value.__typename)
+        }
+      }
+    }
+  }
+}

apollo-compiler/src/test/graphql/com/example/interface_on_interface/schema.sdl

@@ -0,0 +1,19 @@
+type Query {
+  human: Human!
+  node: Node!
+}
+
+interface Node {
+  id: ID!
+}
+
+interface Character implements Node {
+  id: ID!
+  name: String!
+}
+
+type Human implements Character {
+  id: ID!
+  name: String!
+  height: Float!
+}

apollo-compiler/src/test/kotlin/com/apollographql/apollo/compiler/PossibleTypesTest.kt

@@ -0,0 +1,18 @@
+package com.apollographql.apollo.compiler
+
+import com.apollographql.apollo.compiler.frontend.GraphQLParser
+import com.apollographql.apollo.compiler.frontend.possibleTypes
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import java.io.File
+
+class PossibleTypesTest {
+  @Test
+  fun testPossibleTypes() {
+    val schema = GraphQLParser.parseSchema(File("src/test/sdl/schema.sdl"))
+
+    val possibleTypes = schema.typeDefinition("Node").possibleTypes(schema.typeDefinitions)
+
+    assertThat(possibleTypes).isEqualTo(setOf("Empire", "Rebellion"))
+  }
+}

apollo-compiler/src/test/sdl/schema.sdl

@@ -424,3 +424,24 @@ schema {
   query: Query
   mutation: Mutation
 }
+
+interface Node {
+  id: ID!
+}
+
+interface Organization implements Node {
+  id: ID!
+  name: String!
+}
+
+type Empire implements Organization {
+  id: ID!
+  name: String!
+  emperor: String!
+}
+
+type Rebellion implements Organization {
+  id: ID!
+  name: String!
+  emperor: String!
+}