client: shared response types across operations (useSharedResponseTypes opt-in)

plugins/client/graphql-kotlin-client-generator/src/main/kotlin/com/expediagroup/graphql/plugin/client/generateClient.kt

@@ -35,6 +35,7 @@ fun generateClient(
     schemaPath: String,
     queries: List<File>,
     useOptionalInputWrapper: Boolean = false,
+    useSharedResponseTypes: Boolean = false,
     parserOptions: ParserOptions.Builder.() -> Unit = {}
 ): List<FileSpec> {
     val customScalars = customScalarsMap.associateBy { it.scalar }
@@ -44,7 +45,8 @@ fun generateClient(
         customScalarMap = customScalars,
         serializer = serializer,
         useOptionalInputWrapper = useOptionalInputWrapper,
-        parserOptions = parserOptions
+        parserOptions = parserOptions,
+        useSharedResponseTypes = useSharedResponseTypes
     )
     val generator = GraphQLClientGenerator(schemaPath, config)
     return generator.generate(queries)

plugins/client/graphql-kotlin-client-generator/src/main/kotlin/com/expediagroup/graphql/plugin/client/generator/GraphQLClientGenerator.kt

@@ -53,6 +53,10 @@ class GraphQLClientGenerator(
     private val documentParser: Parser = Parser()
     private val typeAliases: MutableMap<String, TypeAliasSpec> = mutableMapOf()
     private val sharedTypes: MutableMap<ClassName, List<TypeSpec>> = mutableMapOf()
+    private val sharedResponseTypeSpecs: MutableMap<ClassName, TypeSpec> = mutableMapOf()
+    private val globalClassNameCache: MutableMap<String, MutableList<ClassName>> = mutableMapOf()
+    private val globalTypeToSelectionSetMap: MutableMap<String, Set<String>> = mutableMapOf()
+
     private var generateOptionalSerializer: Boolean = false
     private val graphQLSchema: TypeDefinitionRegistry
     private val parserOptions: ParserOptions = ParserOptions.newParserOptions().also { this.config.parserOptions(it) }.build()
@@ -119,7 +123,11 @@ class GraphQLClientGenerator(
                 allowDeprecated = config.allowDeprecated,
                 customScalarMap = config.customScalarMap,
                 serializer = config.serializer,
-                useOptionalInputWrapper = config.useOptionalInputWrapper
+                useOptionalInputWrapper = config.useOptionalInputWrapper,
+                sharedClassNameCache = if (config.useSharedResponseTypes) globalClassNameCache else null,
+                sharedTypeToSelectionSetMap = if (config.useSharedResponseTypes) globalTypeToSelectionSetMap else null,
+                useSharedResponseTypes = config.useSharedResponseTypes,
+                sharedResponseTypeSpecs = if (config.useSharedResponseTypes) sharedResponseTypeSpecs else null
             )
             val queryConstName = capitalizedOperationName.toUpperUnderscore()
             val queryConstProp = PropertySpec.builder(queryConstName, STRING)
@@ -205,17 +213,23 @@ class GraphQLClientGenerator(
                 fileSpecs.add(polymorphicTypeSpec.build())
             }
             context.typeSpecs.minus(polymorphicTypes).forEach { (className, typeSpec) ->
-                val outputTypeFileSpec = FileSpec.builder(className.packageName, className.simpleName)
-                    .addType(typeSpec)
-                    .build()
-                fileSpecs.add(outputTypeFileSpec)
+                if (!(config.useSharedResponseTypes && context.isSharedResponseType(className))) {
+                    val outputTypeFileSpec = FileSpec.builder(className.packageName, className.simpleName)
+                        .addType(typeSpec)
+                        .build()
+                    fileSpecs.add(outputTypeFileSpec)
+                }
             }
             operationFileSpec.addType(operationTypeSpec.build())
             fileSpecs.add(operationFileSpec.build())
 
             // shared types
             sharedTypes.putAll(context.enumClassToTypeSpecs.mapValues { listOf(it.value) })
             sharedTypes.putAll(context.inputClassToTypeSpecs.mapValues { listOf(it.value) })
+        if (config.useSharedResponseTypes) {
+            sharedTypes.putAll(sharedResponseTypeSpecs.mapValues { listOf(it.value) })
+        }
+
             context.scalarClassToConverterTypeSpecs
                 .values
                 .forEach {

plugins/client/graphql-kotlin-client-generator/src/main/kotlin/com/expediagroup/graphql/plugin/client/generator/GraphQLClientGeneratorConfig.kt

@@ -34,7 +34,9 @@ data class GraphQLClientGeneratorConfig(
     /** Explicit opt-in flag to enable support for optional inputs. */
     val useOptionalInputWrapper: Boolean = false,
     /** Set parser options for processing GraphQL queries and schema definition language documents */
-    val parserOptions: ParserOptions.Builder.() -> Unit = {}
+    val parserOptions: ParserOptions.Builder.() -> Unit = {},
+    /** Opt-in flag to enable cross-operation shared response types. */
+    val useSharedResponseTypes: Boolean = false
 )
 
 /**

plugins/client/graphql-kotlin-client-generator/src/main/kotlin/com/expediagroup/graphql/plugin/client/generator/GraphQLClientGeneratorContext.kt

@@ -36,7 +36,11 @@ data class GraphQLClientGeneratorContext(
     val allowDeprecated: Boolean = false,
     val customScalarMap: Map<String, GraphQLScalar> = mapOf(),
     val serializer: GraphQLSerializer = GraphQLSerializer.JACKSON,
-    val useOptionalInputWrapper: Boolean = false
+    val useOptionalInputWrapper: Boolean = false,
+    val sharedClassNameCache: MutableMap<String, MutableList<ClassName>>? = null,
+    val sharedTypeToSelectionSetMap: MutableMap<String, Set<String>>? = null,
+    val useSharedResponseTypes: Boolean = false,
+    val sharedResponseTypeSpecs: MutableMap<ClassName, TypeSpec>? = null
 ) {
     // per operation caches
     val typeSpecs: MutableMap<ClassName, TypeSpec> = mutableMapOf()
@@ -50,13 +54,14 @@ data class GraphQLClientGeneratorContext(
     internal fun isTypeAlias(typeName: String) = typeAliases.containsKey(typeName)
 
     // class name and type selection caches
-    val classNameCache: MutableMap<String, MutableList<ClassName>> = mutableMapOf()
-    val typeToSelectionSetMap: MutableMap<String, Set<String>> = mutableMapOf()
+    val classNameCache: MutableMap<String, MutableList<ClassName>> = sharedClassNameCache ?: mutableMapOf()
+    val typeToSelectionSetMap: MutableMap<String, Set<String>> = sharedTypeToSelectionSetMap ?: mutableMapOf()
 
     private val customScalarClassNames: Set<ClassName> = customScalarMap.values.map { it.className }.toSet()
     internal fun isCustomScalar(typeName: TypeName): Boolean = customScalarClassNames.contains(typeName)
     var requireOptionalSerializer = false
     val optionalSerializers: MutableMap<ClassName, TypeSpec> = mutableMapOf()
+    fun isSharedResponseType(className: ClassName): Boolean = useSharedResponseTypes && sharedResponseTypeSpecs?.containsKey(className) == true
 }
 
 sealed class ScalarConverterInfo {

plugins/client/graphql-kotlin-client-generator/src/main/kotlin/com/expediagroup/graphql/plugin/client/generator/types/generateTypeName.kt

@@ -112,7 +112,12 @@ internal fun generateCustomClassName(context: GraphQLClientGeneratorContext, gra
             when (graphQLTypeDefinition) {
                 is ObjectTypeDefinition -> {
                     className = generateClassName(context, graphQLTypeDefinition, selectionSet)
-                    context.typeSpecs[className] = generateGraphQLObjectTypeSpec(context, graphQLTypeDefinition, selectionSet)
+                    val typeSpec = generateGraphQLObjectTypeSpec(context, graphQLTypeDefinition, selectionSet)
+                    if (context.useSharedResponseTypes) {
+                        context.sharedResponseTypeSpecs?.set(className, typeSpec)
+                    } else {
+                        context.typeSpecs[className] = typeSpec
+                    }
                 }
                 is InputObjectTypeDefinition -> {
                     className = generateClassName(context, graphQLTypeDefinition, selectionSet, packageName = "${context.packageName}.inputs")
@@ -174,7 +179,11 @@ internal fun generateCustomClassName(context: GraphQLClientGeneratorContext, gra
             // should never happen as we can only generate different object, interface or union type
             else -> throw UnknownGraphQLTypeException(graphQLType)
         }
-        context.typeSpecs[className] = typeSpec
+        if (graphQLTypeDefinition is ObjectTypeDefinition && context.useSharedResponseTypes) {
+            context.sharedResponseTypeSpecs?.set(className, typeSpec)
+        } else {
+            context.typeSpecs[className] = typeSpec
+        }
         className
     }
 }
@@ -187,7 +196,11 @@ internal fun generateClassName(
     graphQLType: NamedNode<*>,
     selectionSet: SelectionSet? = null,
     nameOverride: String? = null,
-    packageName: String = "${context.packageName}.${context.operationName.lowercase()}"
+    packageName: String = if (graphQLType is ObjectTypeDefinition && context.useSharedResponseTypes) {
+        "${context.packageName}.responses"
+    } else {
+        "${context.packageName}.${context.operationName.lowercase()}"
+    }
 ): ClassName {
     val typeName = nameOverride ?: graphQLType.name
     val className = ClassName(packageName, typeName)

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/Operation1.graphql

@@ -0,0 +1,33 @@
+query Operation1 {
+  first: complexObjectQuery {
+    id
+    name
+  }
+  second: complexObjectQuery {
+    id
+    name
+    details {
+      id
+      value
+    }
+  }
+  third: complexObjectQuery {
+    id
+    name
+    details {
+      id
+    }
+  }
+  fourth: complexObjectQuery {
+    id
+    name
+  }
+  fifth: complexObjectQuery {
+    id
+    name
+    details {
+      id
+      value
+    }
+  }
+}

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/Operation2.graphql

@@ -0,0 +1,33 @@
+query Operation2 {
+  first: complexObjectQuery {
+    id
+    name
+  }
+  second: complexObjectQuery {
+    id
+    name
+    details {
+      id
+      value
+    }
+  }
+  third: complexObjectQuery {
+    id
+    name
+    details {
+      id
+    }
+  }
+  fourth: complexObjectQuery {
+    id
+    name
+  }
+  fifth: complexObjectQuery {
+    id
+    name
+    details {
+      id
+      value
+    }
+  }
+}

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/operation1/Operation1.kt

@@ -0,0 +1,29 @@
+package com.expediagroup.generated
+
+import com.expediagroup.generated.responses.ComplexObject
+import com.expediagroup.generated.responses.ComplexObject2
+import com.expediagroup.generated.responses.ComplexObject3
+import com.expediagroup.graphql.client.Generated
+import com.expediagroup.graphql.client.types.GraphQLClientRequest
+import kotlin.String
+import kotlin.reflect.KClass
+
+@Generated
+class Operation1 : GraphQLClientRequest<Operation1.Result> {
+  override val query: String = OPERATION_1
+
+  override val operationName: String = "Operation1"
+
+  override fun responseType(): KClass<Result> = Result::class
+
+  class Result(
+    val first: ComplexObject,
+    val second: ComplexObject2,
+    val third: ComplexObject3,
+    val fourth: ComplexObject,
+    val fifth: ComplexObject2,
+  )
+}
+
+const val OPERATION_1: String =
+    "query Operation1 {\n  first: complexObjectQuery {\n    id\n    name\n  }\n  second: complexObjectQuery {\n    id\n    name\n    details {\n      id\n      value\n    }\n  }\n  third: complexObjectQuery {\n    id\n    name\n    details {\n      id\n    }\n  }\n  fourth: complexObjectQuery {\n    id\n    name\n  }\n  fifth: complexObjectQuery {\n    id\n    name\n    details {\n      id\n      value\n    }\n  }\n}"

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/operation2/Operation2.kt

@@ -0,0 +1,29 @@
+package com.expediagroup.generated
+
+import com.expediagroup.generated.responses.ComplexObject
+import com.expediagroup.generated.responses.ComplexObject2
+import com.expediagroup.generated.responses.ComplexObject3
+import com.expediagroup.graphql.client.Generated
+import com.expediagroup.graphql.client.types.GraphQLClientRequest
+import kotlin.String
+import kotlin.reflect.KClass
+
+@Generated
+class Operation2 : GraphQLClientRequest<Operation2.Result> {
+  override val query: String = OPERATION_2
+
+  override val operationName: String = "Operation2"
+
+  override fun responseType(): KClass<Result> = Result::class
+
+  class Result(
+    val first: ComplexObject,
+    val second: ComplexObject2,
+    val third: ComplexObject3,
+    val fourth: ComplexObject,
+    val fifth: ComplexObject2,
+  )
+}
+
+const val OPERATION_2: String =
+    "query Operation2 {\n  first: complexObjectQuery {\n    id\n    name\n  }\n  second: complexObjectQuery {\n    id\n    name\n    details {\n      id\n      value\n    }\n  }\n  third: complexObjectQuery {\n    id\n    name\n    details {\n      id\n    }\n  }\n  fourth: complexObjectQuery {\n    id\n    name\n  }\n  fifth: complexObjectQuery {\n    id\n    name\n    details {\n      id\n      value\n    }\n  }\n}"

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/responses/ComplexObject.kt

@@ -0,0 +1,9 @@
+package com.expediagroup.generated.responses
+
+import com.expediagroup.graphql.client.Generated
+
+@Generated
+class ComplexObject(
+  val id: kotlin.Int,
+  val name: kotlin.String,
+)

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/responses/ComplexObject2.kt

@@ -0,0 +1,10 @@
+package com.expediagroup.generated.responses
+
+import com.expediagroup.graphql.client.Generated
+
+@Generated
+class ComplexObject2(
+  val id: kotlin.Int,
+  val name: kotlin.String,
+  val details: DetailsObject,
+)

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/responses/ComplexObject3.kt

@@ -0,0 +1,10 @@
+package com.expediagroup.generated.responses
+
+import com.expediagroup.graphql.client.Generated
+
+@Generated
+class ComplexObject3(
+  val id: kotlin.Int,
+  val name: kotlin.String,
+  val details: DetailsObject?,
+)

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/responses/DetailsObject.kt

@@ -0,0 +1,9 @@
+package com.expediagroup.generated.responses
+
+import com.expediagroup.graphql.client.Generated
+
+@Generated
+class DetailsObject(
+  val id: kotlin.Int,
+  val value: kotlin.String,
+)

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/responses/DetailsObject2.kt

@@ -0,0 +1,8 @@
+package com.expediagroup.generated.responses
+
+import com.expediagroup.graphql.client.Generated
+
+@Generated
+class DetailsObject2(
+  val id: kotlin.Int,
+)

plugins/client/graphql-kotlin-client-generator/src/test/data/generator/shared_responses/schema.graphql

@@ -0,0 +1,18 @@
+schema {
+  query: Query
+}
+
+type Query {
+  complexObjectQuery: ComplexObject
+}
+
+type ComplexObject {
+  id: ID!
+  name: String!
+  details: DetailsObject
+}
+
+type DetailsObject {
+  id: ID!
+  value: String
+}

plugins/client/graphql-kotlin-client-generator/src/test/kotlin/com/expediagroup/graphql/plugin/client/generator/GenerateGraphQLClientSharedResponsesIT.kt

@@ -0,0 +1,27 @@
+package com.expediagroup.graphql.plugin.client.generator
+
+import com.expediagroup.graphql.plugin.client.generator.GraphQLSerializer
+import com.expediagroup.graphql.plugin.client.generateClient
+import org.junit.jupiter.api.Test
+import java.io.File
+
+class GenerateGraphQLClientSharedResponsesIT {
+    @Test
+    fun `generate client with shared response types across operations`() {
+        val files = generateClient(
+            packageName = "com.expediagroup.generated",
+            allowDeprecated = false,
+            customScalarsMap = emptyList(),
+            serializer = GraphQLSerializer.JACKSON,
+            schemaPath = "src/test/data/generator/shared_responses/schema.graphql",
+            queries = listOf(
+                File("src/test/data/generator/shared_responses/Operation1.graphql"),
+                File("src/test/data/generator/shared_responses/Operation2.graphql")
+            ),
+            useOptionalInputWrapper = false,
+            useSharedResponseTypes = true
+        )
+        val namesByPackage = files.groupBy({ it.packageName }, { it.name }).mapValues { entry -> entry.value.toSet() }
+        check(namesByPackage["com.expediagroup.generated.responses"]?.containsAll(setOf("ComplexObject", "ComplexObject2", "ComplexObject3")) == true)
+    }
+}

plugins/client/graphql-kotlin-client-generator/src/test/kotlin/com/expediagroup/graphql/plugin/client/generator/GraphQLTestUtils.kt

@@ -32,7 +32,7 @@ internal val defaultConfig = GraphQLClientGeneratorConfig(packageName = "com.exp
 
 internal fun locateTestCaseArguments(directory: String) = File(directory)
     .listFiles()
-    ?.filter { it.isDirectory }
+    ?.filter { it.isDirectory && it.name != "shared_responses" }
     ?.map {
         Arguments.of(it)
     } ?: emptyList()

plugins/graphql-kotlin-gradle-plugin/src/main/kotlin/com/expediagroup/graphql/plugin/gradle/GraphQLPluginExtension.kt

@@ -90,7 +90,8 @@ open class GraphQLPluginClientExtension {
     var serializer: GraphQLSerializer = GraphQLSerializer.JACKSON
     /** Opt-in flag to wrap nullable arguments in OptionalInput that supports both null and undefined. */
     var useOptionalInputWrapper: Boolean = false
-
+    /** Opt-in flag to enable cross-operation shared response types. */
+    var useSharedResponseTypes: Boolean = false
     /** Connect and read timeout configuration for executing introspection query/download schema */
     internal val timeoutConfig: TimeoutConfiguration = TimeoutConfiguration()