basic support for a fragment file

plugins/client/graphql-kotlin-client-generator/README.md

@@ -27,5 +27,5 @@ using [square/kotlinpoet](https://github.com/square/kotlinpoet) library.
 
 ## Code Generation Limitations
 
-* Only a single operation per GraphQL query file is supported.
+* Only a single operation per GraphQL query file is supported. To avoid duplication of return types, a shared fragments file can be used.
 * Subscriptions are currently NOT supported.

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

@@ -35,7 +35,8 @@ fun generateClient(
     schemaPath: String,
     queries: List<File>,
     useOptionalInputWrapper: Boolean = false,
-    parserOptions: ParserOptions.Builder.() -> Unit = {}
+    parserOptions: ParserOptions.Builder.() -> Unit = {},
+    fragmentsFile: File?
 ): List<FileSpec> {
     val customScalars = customScalarsMap.associateBy { it.scalar }
     val config = GraphQLClientGeneratorConfig(
@@ -47,5 +48,5 @@ fun generateClient(
         parserOptions = parserOptions
     )
     val generator = GraphQLClientGenerator(schemaPath, config)
-    return generator.generate(queries)
+    return generator.generate(queries, fragmentsFile)
 }

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

@@ -17,6 +17,7 @@
 package com.expediagroup.graphql.plugin.client.generator
 
 import com.expediagroup.graphql.client.Generated
+import com.expediagroup.graphql.plugin.client.generator.exceptions.InvalidFragmentFileException
 import com.expediagroup.graphql.plugin.client.generator.exceptions.MultipleOperationsInFileException
 import com.expediagroup.graphql.plugin.client.generator.exceptions.SchemaUnavailableException
 import com.expediagroup.graphql.plugin.client.generator.types.generateGraphQLObjectTypeSpec
@@ -30,6 +31,8 @@ import com.squareup.kotlinpoet.PropertySpec
 import com.squareup.kotlinpoet.STRING
 import com.squareup.kotlinpoet.TypeAliasSpec
 import com.squareup.kotlinpoet.TypeSpec
+import graphql.language.Document
+import graphql.language.FragmentDefinition
 import graphql.language.ObjectTypeDefinition
 import graphql.language.OperationDefinition
 import graphql.parser.Parser
@@ -63,10 +66,22 @@ class GraphQLClientGenerator(
     /**
      * Generate GraphQL clients for the specified queries.
      */
-    fun generate(queries: List<File>): List<FileSpec> {
+    fun generate(queries: List<File>, fragmentsFile: File? = null): List<FileSpec> {
+
         val result = mutableListOf<FileSpec>()
+
+        val fragmentsDocument = fragmentsFile?.let {
+            val fragmentsConst = fragmentsFile.readText().trim()
+            val d = documentParser.parseDocument(fragmentsConst, parserOptions)
+            d.definitions.forEach {
+                if (it !is FragmentDefinition) {
+                    throw InvalidFragmentFileException(fragmentsFile)
+                }
+            }
+            d
+        }
         for (query in queries) {
-            result.addAll(generate(query))
+            result.addAll(generate(query, fragmentsFile, fragmentsDocument))
         }
 
         // common shared types
@@ -86,13 +101,13 @@ class GraphQLClientGenerator(
             }
             result.add(typeAliasSpec.build())
         }
-        return result
+        return result.distinctBy { it.packageName + it.name }
     }
 
     /**
      * Generate GraphQL client wrapper class and data classes that match the specified query.
      */
-    internal fun generate(queryFile: File): List<FileSpec> {
+    internal fun generate(queryFile: File, fragmentsFile: File?, fragmentsDocument: Document?): List<FileSpec> {
         val queryConst = queryFile.readText().trim()
         val queryDocument = documentParser.parseDocument(queryConst, parserOptions)
 
@@ -113,12 +128,18 @@ class GraphQLClientGenerator(
                 allowDeprecated = config.allowDeprecated,
                 customScalarMap = config.customScalarMap,
                 serializer = config.serializer,
-                useOptionalInputWrapper = config.useOptionalInputWrapper
+                useOptionalInputWrapper = config.useOptionalInputWrapper,
+                fragmentsFile = fragmentsDocument
             )
             val queryConstName = capitalizedOperationName.toUpperUnderscore()
             val queryConstProp = PropertySpec.builder(queryConstName, STRING)
                 .addModifiers(KModifier.CONST)
-                .initializer("%S", queryConst)
+                .initializer(
+                    "%S",
+                    fragmentsFile?.let {
+                        queryConst + "\n\n" + fragmentsFile.readText().trim() // todo only add relevant fragments
+                    } ?: queryConst
+                )
                 .build()
             operationFileSpec.addProperty(queryConstProp)
 

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

@@ -36,7 +36,8 @@ 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 fragmentsFile: Document? = null,
 ) {
     // per operation caches
     val typeSpecs: MutableMap<ClassName, TypeSpec> = mutableMapOf()

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

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 Expedia, Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.expediagroup.graphql.plugin.client.generator.exceptions
+
+import java.io.File
+
+/**
+ * Exception thrown when attempting to generate a client with a fragments file containing not allowed definitions.
+ */
+internal class InvalidFragmentFileException(queryFile: File) :
+    RuntimeException("GraphQL client does not support a fragments file with other definitions than fragments, ${queryFile.name}")

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

@@ -22,6 +22,13 @@ import graphql.language.Document
 import graphql.language.FragmentDefinition
 
 internal fun Document.findFragmentDefinition(context: GraphQLClientGeneratorContext, targetFragment: String, targetType: String): FragmentDefinition =
+    findFragmentDefinitionNullable(context, targetFragment, targetType)
+        ?: throw InvalidFragmentException(context.operationName, targetFragment, targetType)
+
+internal fun Document.findFragmentDefinitionNullable(context: GraphQLClientGeneratorContext, targetFragment: String, targetType: String): FragmentDefinition? =
     this.getDefinitionsOfType(FragmentDefinition::class.java)
         .find { it.name == targetFragment && context.graphQLSchema.getType(it.typeCondition.name).isPresent }
-        ?: throw InvalidFragmentException(context.operationName, targetFragment, targetType)
+
+internal fun GraphQLClientGeneratorContext.findFragmentDefinition(targetFragment: String, targetType: String): FragmentDefinition {
+    return this.fragmentsFile?.findFragmentDefinitionNullable(this, targetFragment, targetType) ?: this.queryDocument.findFragmentDefinition(this, targetFragment, targetType)
+}

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

@@ -78,8 +78,8 @@ internal fun generateGraphQLObjectTypeSpec(
 
     selectionSet.getSelectionsOfType(FragmentSpread::class.java)
         .forEach { fragment ->
-            val fragmentDefinition = context.queryDocument
-                .findFragmentDefinition(context, fragment.name, objectDefinition.name)
+            val fragmentDefinition = context
+                .findFragmentDefinition(fragment.name, objectDefinition.name)
             generatePropertySpecs(
                 context = context,
                 objectName = objectDefinition.name,

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

@@ -21,6 +21,7 @@ import com.expediagroup.graphql.plugin.client.generator.GraphQLSerializer
 import com.expediagroup.graphql.plugin.client.generator.ScalarConverterInfo
 import com.expediagroup.graphql.plugin.client.generator.exceptions.UnknownGraphQLTypeException
 import com.expediagroup.graphql.plugin.client.generator.extensions.findFragmentDefinition
+import com.expediagroup.graphql.plugin.client.generator.extensions.findFragmentDefinitionNullable
 import com.squareup.kotlinpoet.AnnotationSpec
 import com.squareup.kotlinpoet.BOOLEAN
 import com.squareup.kotlinpoet.ClassName
@@ -68,6 +69,7 @@ internal fun generateTypeName(
             Scalars.GraphQLBoolean.name -> BOOLEAN
             else -> generateCustomClassName(context, graphQLType, selectionSet)
         }
+
         is ListType -> {
             val type = generateTypeName(context, graphQLType.type, selectionSet)
             val parameterizedType = if (context.serializer == GraphQLSerializer.KOTLINX && context.isCustomScalar(type)) {
@@ -114,24 +116,29 @@ internal fun generateCustomClassName(context: GraphQLClientGeneratorContext, gra
                     className = generateClassName(context, graphQLTypeDefinition, selectionSet)
                     context.typeSpecs[className] = generateGraphQLObjectTypeSpec(context, graphQLTypeDefinition, selectionSet)
                 }
+
                 is InputObjectTypeDefinition -> {
                     className = generateClassName(context, graphQLTypeDefinition, selectionSet, packageName = "${context.packageName}.inputs")
                     context.inputClassToTypeSpecs[className] = generateGraphQLInputObjectTypeSpec(context, graphQLTypeDefinition)
                 }
+
                 is EnumTypeDefinition -> {
                     className = generateClassName(context, graphQLTypeDefinition, selectionSet, packageName = "${context.packageName}.enums")
                     context.enumClassToTypeSpecs[className] = generateGraphQLEnumTypeSpec(context, graphQLTypeDefinition)
                 }
+
                 is InterfaceTypeDefinition -> {
                     className = generateClassName(context, graphQLTypeDefinition, selectionSet)
                     context.polymorphicTypes[className] = mutableListOf(className)
                     context.typeSpecs[className] = generateGraphQLInterfaceTypeSpec(context, graphQLTypeDefinition, selectionSet)
                 }
+
                 is UnionTypeDefinition -> {
                     className = generateClassName(context, graphQLTypeDefinition, selectionSet)
                     context.polymorphicTypes[className] = mutableListOf(className)
                     context.typeSpecs[className] = generateGraphQLUnionTypeSpec(context, graphQLTypeDefinition, selectionSet)
                 }
+
                 is ScalarTypeDefinition -> {
                     // its not possible to enter this clause if converter is not available
                     val graphQLScalarMapping = context.customScalarMap[graphQLTypeName]!!
@@ -167,6 +174,7 @@ internal fun generateCustomClassName(context: GraphQLClientGeneratorContext, gra
                 context.polymorphicTypes[className] = mutableListOf(className)
                 generateGraphQLInterfaceTypeSpec(context, graphQLTypeDefinition, selectionSet, overriddenName)
             }
+
             is UnionTypeDefinition -> {
                 context.polymorphicTypes[className] = mutableListOf(className)
                 generateGraphQLUnionTypeSpec(context, graphQLTypeDefinition, selectionSet, overriddenName)
@@ -189,8 +197,18 @@ internal fun generateClassName(
     nameOverride: String? = null,
     packageName: String = "${context.packageName}.${context.operationName.lowercase()}"
 ): ClassName {
+    var pName = packageName
+    selectionSet?.let {
+        if (it.selections.size == 1 && it.selections.first() is FragmentSpread) {
+            val first = it.selections.first() as FragmentSpread
+            val isSharedFragment = context.fragmentsFile?.findFragmentDefinitionNullable(context, first.name, nameOverride ?: graphQLType.name) != null
+            if (isSharedFragment) {
+                pName = "${context.packageName}.fragments"
+            }
+        }
+    }
     val typeName = nameOverride ?: graphQLType.name
-    val className = ClassName(packageName, typeName)
+    val className = ClassName(pName, typeName)
     val classNames = context.classNameCache.getOrDefault(graphQLType.name, mutableListOf())
     classNames.add(className)
     context.classNameCache[graphQLType.name] = classNames
@@ -235,6 +253,7 @@ private fun calculateSelectedFields(
                     result.addAll(calculateSelectedFields(context, targetType, selection.selectionSet, "$path$fieldName."))
                 }
             }
+
             is InlineFragment -> {
                 val targetFragmentType = selection.typeCondition.name
                 val fragmentPathPrefix = if (targetFragmentType == targetType) {
@@ -244,8 +263,10 @@ private fun calculateSelectedFields(
                 }
                 result.addAll(calculateSelectedFields(context, targetType, selection.selectionSet, fragmentPathPrefix))
             }
+
             is FragmentSpread -> {
-                val fragmentDefinition = context.queryDocument.findFragmentDefinition(context, selection.name, targetType)
+                val fragmentDefinition = context.findFragmentDefinition(selection.name, targetType)
+
                 val targetFragmentType = fragmentDefinition.typeCondition.name
                 val fragmentPathPrefix = if (targetFragmentType == targetType) {
                     path

plugins/client/graphql-kotlin-client-generator/src/test/data/fragments/Fragments.graphql

@@ -0,0 +1,11 @@
+fragment complexObjectFields on ComplexObject {
+  id
+  name
+  details {
+    ...detailObjectFields
+  }
+}
+
+fragment detailObjectFields on DetailsObject {
+  value
+}

plugins/client/graphql-kotlin-client-generator/src/test/data/fragments/object_named_fragments/ObjectWithNamedFragmentQuery.graphql

@@ -0,0 +1,5 @@
+query ObjectWithNamedFragmentQuery {
+  complexObjectQuery {
+    ...complexObjectFields
+  }
+}

plugins/client/graphql-kotlin-client-generator/src/test/data/fragments/object_named_fragments/ObjectWithNamedFragmentQuery.kt

@@ -0,0 +1,29 @@
+package com.expediagroup.graphql.generated
+
+import com.expediagroup.graphql.client.Generated
+import com.expediagroup.graphql.client.types.GraphQLClientRequest
+import com.expediagroup.graphql.generated.fragments.ComplexObject
+import kotlin.String
+import kotlin.reflect.KClass
+
+public const val OBJECT_WITH_NAMED_FRAGMENT_QUERY: String =
+    "query ObjectWithNamedFragmentQuery {\n  complexObjectQuery {\n    ...complexObjectFields\n  }\n}\n\nfragment complexObjectFields on ComplexObject {\n  id\n  name\n  details {\n    ...detailObjectFields\n  }\n}\n\nfragment detailObjectFields on DetailsObject {\n  value\n}"
+
+@Generated
+public class ObjectWithNamedFragmentQuery :
+    GraphQLClientRequest<ObjectWithNamedFragmentQuery.Result> {
+  override val query: String = OBJECT_WITH_NAMED_FRAGMENT_QUERY
+
+  override val operationName: String = "ObjectWithNamedFragmentQuery"
+
+  override fun responseType(): KClass<ObjectWithNamedFragmentQuery.Result> =
+      ObjectWithNamedFragmentQuery.Result::class
+
+  @Generated
+  public data class Result(
+    /**
+     * Query returning an object that references another object
+     */
+    public val complexObjectQuery: ComplexObject,
+  )
+}

plugins/client/graphql-kotlin-client-generator/src/test/data/fragments/object_named_fragments/ObjectWithNamedFragmentQuery2.graphql

@@ -0,0 +1,7 @@
+query ObjectWithNamedFragmentQuery2 {
+  complexObjectQuery {
+    ...complexObjectFields
+  }
+}
+
+

plugins/client/graphql-kotlin-client-generator/src/test/data/fragments/object_named_fragments/ObjectWithNamedFragmentQuery2.kt

@@ -0,0 +1,29 @@
+package com.expediagroup.graphql.generated
+
+import com.expediagroup.graphql.client.Generated
+import com.expediagroup.graphql.client.types.GraphQLClientRequest
+import com.expediagroup.graphql.generated.fragments.ComplexObject
+import kotlin.String
+import kotlin.reflect.KClass
+
+public const val OBJECT_WITH_NAMED_FRAGMENT_QUERY2: String =
+    "query ObjectWithNamedFragmentQuery2 {\n  complexObjectQuery {\n    ...complexObjectFields\n  }\n}\n\nfragment complexObjectFields on ComplexObject {\n  id\n  name\n  details {\n    ...detailObjectFields\n  }\n}\n\nfragment detailObjectFields on DetailsObject {\n  value\n}"
+
+@Generated
+public class ObjectWithNamedFragmentQuery2 :
+    GraphQLClientRequest<ObjectWithNamedFragmentQuery2.Result> {
+  override val query: String = OBJECT_WITH_NAMED_FRAGMENT_QUERY2
+
+  override val operationName: String = "ObjectWithNamedFragmentQuery2"
+
+  override fun responseType(): KClass<ObjectWithNamedFragmentQuery2.Result> =
+      ObjectWithNamedFragmentQuery2.Result::class
+
+  @Generated
+  public data class Result(
+    /**
+     * Query returning an object that references another object
+     */
+    public val complexObjectQuery: ComplexObject,
+  )
+}

plugins/client/graphql-kotlin-client-generator/src/test/data/fragments/object_named_fragments/fragments/ComplexObject.kt

@@ -0,0 +1,26 @@
+package com.expediagroup.graphql.generated.fragments
+
+import com.expediagroup.graphql.client.Generated
+import kotlin.Int
+import kotlin.String
+
+/**
+ * Multi line description of a complex type.
+ * This is a second line of the paragraph.
+ * This is final line of the description.
+ */
+@Generated
+public data class ComplexObject(
+  /**
+   * Some unique identifier
+   */
+  public val id: Int,
+  /**
+   * Some object name
+   */
+  public val name: String,
+  /**
+   * Some additional details
+   */
+  public val details: DetailsObject,
+)

plugins/client/graphql-kotlin-client-generator/src/test/data/fragments/object_named_fragments/fragments/DetailsObject.kt

@@ -0,0 +1,15 @@
+package com.expediagroup.graphql.generated.fragments
+
+import com.expediagroup.graphql.client.Generated
+import kotlin.String
+
+/**
+ * Inner type object description
+ */
+@Generated
+public data class DetailsObject(
+  /**
+   * Actual detail value
+   */
+  public val `value`: String,
+)