Custom scalar input (ExpediaGroup#636)

* Add more tests for custom scalar input

* Undo api changes

* Fix input for lists of custom scalars

Converting a list input type for custom scalars was losing the type information. We need to use a specific Jackson conversion method to properly convert the List interface

* Remove reference to external classes in javadoc

Co-authored-by: Shane Myrick <[email protected]>

Author: smyrick

examples/spring/src/main/kotlin/com/expediagroup/graphql/examples/query/ScalarQuery.kt

@@ -32,6 +32,9 @@ class ScalarQuery : Query {
     @GraphQLDescription("generates random UUID")
     fun generateRandomUUID() = UUID.randomUUID()
 
+    @GraphQLDescription("Prints a string with a custom scalar as input")
+    fun printUuids(uuids: List<UUID>) = "You sent $uuids"
+
     fun findPersonById(@GraphQLID id: String) = Person(id, "Nelson")
 }
 

graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/execution/FunctionDataFetcher.kt

@@ -16,10 +16,12 @@
 
 package com.expediagroup.graphql.execution
 
+import com.expediagroup.graphql.generator.extensions.getJavaClass
 import com.expediagroup.graphql.generator.extensions.getName
+import com.expediagroup.graphql.generator.extensions.getTypeOfFirstArgument
 import com.expediagroup.graphql.generator.extensions.isDataFetchingEnvironment
 import com.expediagroup.graphql.generator.extensions.isGraphQLContext
-import com.expediagroup.graphql.generator.extensions.javaTypeClass
+import com.expediagroup.graphql.generator.extensions.isList
 import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import graphql.schema.DataFetcher
@@ -95,14 +97,20 @@ open class FunctionDataFetcher(
     /**
      * Called to convert the generic input object to the parameter class.
      *
-     * This is currently achieved by using a Jackson [ObjectMapper].
+     * This is currently achieved by using a Jackson ObjectMapper.
      */
     protected open fun convertParameterValue(param: KParameter, environment: DataFetchingEnvironment): Any? {
         val name = param.getName()
-        val klazz = param.javaTypeClass()
         val argument = environment.arguments[name]
 
-        return objectMapper.convertValue(argument, klazz)
+        return if (param.isList()) {
+            val argumentClass = param.type.getTypeOfFirstArgument().getJavaClass()
+            val jacksonCollectionType = objectMapper.typeFactory.constructCollectionType(List::class.java, argumentClass)
+            objectMapper.convertValue(argument, jacksonCollectionType)
+        } else {
+            val javaClass = param.type.getJavaClass()
+            objectMapper.convertValue(argument, javaClass)
+        }
     }
 
     /**

graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/extensions/kParameterExtensions.kt

@@ -22,7 +22,6 @@ import graphql.schema.DataFetchingEnvironment
 import kotlin.reflect.KParameter
 import kotlin.reflect.full.findAnnotation
 import kotlin.reflect.full.isSubclassOf
-import kotlin.reflect.jvm.javaType
 
 internal fun KParameter.isInterface() = this.type.getKClass().isInterface()
 
@@ -35,10 +34,3 @@ internal fun KParameter.isDataFetchingEnvironment() = this.type.classifier == Da
 @Throws(CouldNotGetNameOfKParameterException::class)
 internal fun KParameter.getName(): String =
     this.getGraphQLName() ?: this.name ?: throw CouldNotGetNameOfKParameterException(this)
-
-internal fun KParameter.javaTypeClass(): Class<*> =
-    if (this.isList()) {
-        this.type.getKClass().java
-    } else {
-        this.type.javaType as Class<*>
-    }

graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/extensions/kTypeExtensions.kt

@@ -21,6 +21,7 @@ import kotlin.reflect.KClass
 import kotlin.reflect.KType
 import kotlin.reflect.full.createType
 import kotlin.reflect.full.isSubclassOf
+import kotlin.reflect.jvm.javaType
 import kotlin.reflect.jvm.jvmErasure
 
 private val primitiveArrayTypes = mapOf(
@@ -35,6 +36,8 @@ private val primitiveArrayTypes = mapOf(
 
 internal fun KType.getKClass() = this.jvmErasure
 
+internal fun KType.getJavaClass() = this.javaType as Class<*>
+
 internal fun KType.isSubclassOf(kClass: KClass<*>) = this.getKClass().isSubclassOf(kClass)
 
 @Throws(InvalidListTypeException::class)

graphql-kotlin-schema-generator/src/test/kotlin/com/expediagroup/graphql/generator/extensions/KParameterExtensionsKtTest.kt

@@ -125,13 +125,6 @@ internal class KParameterExtensionsKtTest {
         assertFalse(param?.isDataFetchingEnvironment().isTrue())
     }
 
-    @Test
-    fun javaTypeClass() {
-        assertEquals(expected = String::class.java, actual = MyKotlinClass::stringFun.findParameterByName("string")?.javaTypeClass())
-        assertEquals(expected = List::class.java, actual = Container::listInput.findParameterByName("myList")?.javaTypeClass())
-        assertEquals(expected = MyInterface::class.java, actual = Container::interfaceInput.findParameterByName("myInterface")?.javaTypeClass())
-    }
-
     @Test
     fun isList() {
         assertTrue(Container::listInput.findParameterByName("myList")?.isList() == true)

graphql-kotlin-schema-generator/src/test/kotlin/com/expediagroup/graphql/hooks/SchemaGeneratorHooksTest.kt

@@ -23,10 +23,9 @@ import com.expediagroup.graphql.exceptions.EmptyInterfaceTypeException
 import com.expediagroup.graphql.exceptions.EmptyObjectTypeException
 import com.expediagroup.graphql.generator.extensions.getSimpleName
 import com.expediagroup.graphql.getTestSchemaConfigWithHooks
+import com.expediagroup.graphql.test.utils.graphqlUUIDType
 import com.expediagroup.graphql.testSchemaConfig
 import com.expediagroup.graphql.toSchema
-import graphql.language.StringValue
-import graphql.schema.Coercing
 import graphql.schema.GraphQLFieldDefinition
 import graphql.schema.GraphQLInterfaceType
 import graphql.schema.GraphQLObjectType
@@ -328,21 +327,4 @@ class SchemaGeneratorHooksTest {
     }
 
     class EmptyImplementation(override val id: String) : EmptyInterface
-
-    private val graphqlUUIDType = GraphQLScalarType.newScalar()
-        .name("UUID")
-        .description("A type representing a formatted java.util.UUID")
-        .coercing(UUIDCoercing)
-        .build()
-
-    private object UUIDCoercing : Coercing<UUID, String> {
-        override fun parseValue(input: Any?): UUID = UUID.fromString(serialize(input))
-
-        override fun parseLiteral(input: Any?): UUID? {
-            val uuidString = (input as? StringValue)?.value
-            return UUID.fromString(uuidString)
-        }
-
-        override fun serialize(dataFetcherResult: Any?): String = dataFetcherResult.toString()
-    }
 }

graphql-kotlin-schema-generator/src/test/kotlin/com/expediagroup/graphql/test/integration/CustomScalarExecutionTest.kt

@@ -0,0 +1,94 @@
+/*
+ * Copyright 2020 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.test.integration
+
+import com.expediagroup.graphql.TopLevelObject
+import com.expediagroup.graphql.getTestSchemaConfigWithHooks
+import com.expediagroup.graphql.hooks.SchemaGeneratorHooks
+import com.expediagroup.graphql.test.utils.graphqlUUIDType
+import com.expediagroup.graphql.toSchema
+import graphql.GraphQL
+import graphql.schema.GraphQLType
+import org.junit.jupiter.api.Test
+import java.util.UUID
+import kotlin.reflect.KClass
+import kotlin.reflect.KType
+import kotlin.test.assertEquals
+import kotlin.test.assertFails
+import kotlin.test.assertNotNull
+
+class CustomScalarExecutionTest {
+
+    private val schema = toSchema(
+        queries = listOf(TopLevelObject(QueryObject())),
+        config = getTestSchemaConfigWithHooks(CustomScalarHooks())
+    )
+    private val graphQL: GraphQL = GraphQL.newGraphQL(schema).build()
+
+    @Test
+    fun `a custom scalar can be used as output`() {
+        val result = graphQL.execute("{ uuidOutput }")
+        val data: Map<String, String>? = result.getData()
+
+        assertNotNull(data?.get("uuidOutput"))
+    }
+
+    @Test
+    fun `a custom scalar can be used as input`() {
+        val result = graphQL.execute("{ uuidInput(uuid: \"22dba784-f7c1-471f-8e8c-84e3a59bb5b5\") }")
+        val data: Map<String, String>? = result.getData()
+
+        assertNotNull(data?.get("uuidInput"))
+    }
+
+    @Test
+    fun `an invalid custom scalar as input will throw an error`() {
+        assertFails {
+            graphQL.execute("{ uuidInput(uuid: \"foo\") }")
+        }
+    }
+
+    @Test
+    fun `a custom scalar can be used as input in a list`() {
+        val result = graphQL.execute("{ uuidListInput(uuids: [\"435f5808-936b-40ab-89b6-ec4e8cd1ba36\", \"435f5808-936b-40ab-89b6-ec4e8cd1ba36\"]) }")
+        val data: Map<String, String>? = result.getData()
+
+        assertEquals("You sent 2 items and there are 1 unqiue items", data?.get("uuidListInput"))
+    }
+
+    class QueryObject {
+        fun uuidOutput(): UUID = UUID.randomUUID()
+
+        fun uuidInput(uuid: UUID) = "You sent $uuid"
+
+        fun uuidListInput(uuids: List<UUID>): String {
+            // This verifies that the custom scalar is converted properly by jackson
+            // and we can run comparisons on the original class
+            val group = uuids.groupBy { it }
+            return "You sent ${uuids.size} items and there are ${group.size} unqiue items"
+        }
+    }
+
+    class CustomScalarHooks : SchemaGeneratorHooks {
+        override fun willGenerateGraphQLType(type: KType): GraphQLType? {
+            return when (type.classifier as? KClass<*>) {
+                UUID::class -> graphqlUUIDType
+                else -> null
+            }
+        }
+    }
+}

graphql-kotlin-schema-generator/src/test/kotlin/com/expediagroup/graphql/test/utils/graphqlUuidType.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2020 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.test.utils
+
+import graphql.language.StringValue
+import graphql.schema.Coercing
+import graphql.schema.GraphQLScalarType
+import java.util.UUID
+
+/**
+ * Custom scalar to parse a string as a [UUID] for both input and output.
+ */
+internal val graphqlUUIDType = GraphQLScalarType.newScalar()
+    .name("UUID")
+    .description("A type representing a formatted java.util.UUID")
+    .coercing(UUIDCoercing)
+    .build()
+
+private object UUIDCoercing : Coercing<UUID, String> {
+    override fun parseValue(input: Any?): UUID = UUID.fromString(serialize(input))
+
+    override fun parseLiteral(input: Any?): UUID? {
+        val uuidString: String? = (input as? StringValue)?.value
+        return if (uuidString != null) {
+            UUID.fromString(uuidString)
+        } else null
+    }
+
+    override fun serialize(dataFetcherResult: Any?): String = dataFetcherResult.toString()
+}