[client] support optional input for jackson serializer (ExpediaGroup#…

…1158)

* [client] support optional input for jackson serializer

Wrap optional input arguments in new `OptionalInput` sealed class which can either be `Undefined` (omitted) or `Defined` (value or explicit null). Unfortunately it looks like we won't be able to support this functionality for `kotlinx-serialization` until Kotlin/kotlinx.serialization#1091 is resolved.

Related: ExpediaGroup#1151

* fix build

* add explicit opt-in flag for plugins to use optional input wrapper

clients/graphql-kotlin-client-jackson/build.gradle.kts

@@ -14,7 +14,7 @@ tasks {
  limit {
  counter = "INSTRUCTION"
  value = "COVEREDRATIO"
- minimum = "0.85".toBigDecimal()
+ minimum = "0.89".toBigDecimal()
  }
  }
  }

clients/graphql-kotlin-client-jackson/src/main/kotlin/com/expediagroup/graphql/client/jackson/GraphQLClientJacksonSerializer.kt

@@ -19,6 +19,7 @@ package com.expediagroup.graphql.client.jackson
 import com.expediagroup.graphql.client.jackson.types.JacksonGraphQLResponse
 import com.expediagroup.graphql.client.serializer.GraphQLClientSerializer
 import com.expediagroup.graphql.client.types.GraphQLClientRequest
+import com.fasterxml.jackson.annotation.JsonInclude
 import com.fasterxml.jackson.databind.DeserializationFeature
 import com.fasterxml.jackson.databind.JavaType
 import com.fasterxml.jackson.databind.ObjectMapper
@@ -34,6 +35,7 @@ class GraphQLClientJacksonSerializer(private val mapper: ObjectMapper = jacksonO
 
  init {
  mapper.enable(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_USING_DEFAULT_VALUE)
+ mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY)
  }
 
  override fun serialize(request: GraphQLClientRequest<*>): String = mapper.writeValueAsString(request)

clients/graphql-kotlin-client-jackson/src/main/kotlin/com/expediagroup/graphql/client/jackson/serializers/OptionalInputSerializer.kt

@@ -0,0 +1,42 @@
+/*
+ * 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.client.jackson.serializers
+
+import com.expediagroup.graphql.client.jackson.types.OptionalInput
+import com.fasterxml.jackson.core.JsonGenerator
+import com.fasterxml.jackson.databind.JsonSerializer
+import com.fasterxml.jackson.databind.SerializerProvider
+
+class OptionalInputSerializer : JsonSerializer<OptionalInput<*>>() {
+
+ override fun isEmpty(provider: SerializerProvider, value: OptionalInput<*>?): Boolean {
+ return value == OptionalInput.Undefined
+ }
+
+ override fun serialize(value: OptionalInput<*>, gen: JsonGenerator, serializers: SerializerProvider) {
+ when (value) {
+ is OptionalInput.Undefined -> return
+ is OptionalInput.Defined -> {
+ if (value.value == null) {
+ serializers.defaultNullValueSerializer.serialize(value.value, gen, serializers)
+ } else {
+ serializers.findValueSerializer(value.value::class.java).serialize(value.value, gen, serializers)
+ }
+ }
+ }
+ }
+}

clients/graphql-kotlin-client-jackson/src/main/kotlin/com/expediagroup/graphql/client/jackson/types/OptionalInput.kt

@@ -0,0 +1,41 @@
+/*
+ * 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.client.jackson.types
+
+import com.expediagroup.graphql.client.jackson.serializers.OptionalInputSerializer
+import com.fasterxml.jackson.annotation.JsonCreator
+import com.fasterxml.jackson.annotation.JsonValue
+import com.fasterxml.jackson.databind.annotation.JsonSerialize
+
+@JsonSerialize(using = OptionalInputSerializer::class)
+sealed class OptionalInput<out T> {
+ /**
+ * Represents missing/undefined value.
+ */
+ @JsonSerialize(using = OptionalInputSerializer::class)
+ object Undefined : OptionalInput<Nothing>() {
+ override fun toString() = "Undefined"
+ }
+
+ /**
+ * Wrapper holding explicitly specified value including NULL.
+ */
+ @JsonSerialize(using = OptionalInputSerializer::class)
+ class Defined<out U> @JsonCreator constructor(@JsonValue val value: U?) : OptionalInput<U>() {
+ override fun toString(): String = "Defined(value=$value)"
+ }
+}

clients/graphql-kotlin-client-jackson/src/test/kotlin/com/expediagroup/graphql/client/jackson/GraphQLClientJacksonSerializerTest.kt

@@ -18,6 +18,7 @@ package com.expediagroup.graphql.client.jackson
 
 import com.expediagroup.graphql.client.jackson.data.EnumQuery
 import com.expediagroup.graphql.client.jackson.data.FirstQuery
+import com.expediagroup.graphql.client.jackson.data.InputQuery
 import com.expediagroup.graphql.client.jackson.data.OtherQuery
 import com.expediagroup.graphql.client.jackson.data.PolymorphicQuery
 import com.expediagroup.graphql.client.jackson.data.ScalarQuery
@@ -26,6 +27,7 @@ import com.expediagroup.graphql.client.jackson.data.polymorphicquery.SecondInter
 import com.expediagroup.graphql.client.jackson.types.JacksonGraphQLError
 import com.expediagroup.graphql.client.jackson.types.JacksonGraphQLResponse
 import com.expediagroup.graphql.client.jackson.types.JacksonGraphQLSourceLocation
+import com.expediagroup.graphql.client.jackson.types.OptionalInput
 import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import org.junit.jupiter.api.Test
 import java.util.UUID
@@ -61,8 +63,7 @@ class GraphQLClientJacksonSerializerTest {
  | "variables": { "input": 1.0 }
  |},{
  | "query": "OTHER_QUERY",
- | "operationName": "OtherQuery",
- | "variables": null
+ | "operationName": "OtherQuery"
  |}]
  """.trimMargin()
 
@@ -236,4 +237,29 @@ class GraphQLClientJacksonSerializerTest {
  val deserialized = serializer.deserialize(rawResponse, EnumQuery(EnumQuery.Variables()).responseType())
  assertEquals(TestEnum.THREE, deserialized.data?.enumResult)
  }
+
+ @Test
+ fun `verify we can serialize optional inputs`() {
+ val query = InputQuery(
+ variables = InputQuery.Variables(
+ requiredInput = 123,
+ optionalIntInput = OptionalInput.Defined(123),
+ optionalStringInput = OptionalInput.Defined(null)
+ )
+ )
+ val rawQuery =
+ """{
+ | "query": "INPUT_QUERY",
+ | "operationName": "InputQuery",
+ | "variables": {
+ | "requiredInput": 123,
+ | "optionalIntInput": 123,
+ | "optionalStringInput": null
+ | }
+ |}
+ """.trimMargin()
+
+ val serialized = serializer.serialize(query)
+ assertEquals(testMapper.readTree(rawQuery), testMapper.readTree(serialized))
+ }
 }

clients/graphql-kotlin-client-jackson/src/test/kotlin/com/expediagroup/graphql/client/jackson/data/InputQuery.kt

@@ -0,0 +1,42 @@
+/*
+ * 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.client.jackson.data
+
+import com.expediagroup.graphql.client.jackson.types.OptionalInput
+import com.expediagroup.graphql.client.types.GraphQLClientRequest
+import kotlin.reflect.KClass
+
+class InputQuery(
+ override val variables: Variables
+) : GraphQLClientRequest<InputQuery.Result> {
+ override val query: String = "INPUT_QUERY"
+
+ override val operationName: String = "InputQuery"
+
+ override fun responseType(): KClass<Result> = Result::class
+
+ data class Variables(
+ val requiredInput: Int,
+ val optionalIntInput: OptionalInput<Int> = OptionalInput.Undefined,
+ val optionalStringInput: OptionalInput<String> = OptionalInput.Undefined,
+ val optionalBooleanInput: OptionalInput<Boolean> = OptionalInput.Undefined
+ )
+
+ data class Result(
+ val stringResult: String
+ )
+}

clients/graphql-kotlin-client-jackson/src/test/kotlin/com/expediagroup/graphql/client/jackson/serializers/OptionalInputSerializerTest.kt

@@ -0,0 +1,73 @@
+/*
+ * 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.client.jackson.serializers
+
+import com.expediagroup.graphql.client.jackson.types.OptionalInput
+import com.fasterxml.jackson.annotation.JsonInclude
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import org.junit.jupiter.api.Test
+import kotlin.test.assertEquals
+
+class OptionalInputSerializerTest {
+
+ private val mapper = jacksonObjectMapper()
+ init {
+ mapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY)
+ }
+
+ @Test
+ fun `verify undefined value is serialized to empty JSON`() {
+ val undefined = InputWrapper()
+ assertEquals("{}", mapper.writeValueAsString(undefined))
+ }
+
+ @Test
+ fun `verify null value is serialized correctly`() {
+ val explicitNull = InputWrapper(
+ optionalInput = OptionalInput.Defined(null),
+ optionalInputObject = OptionalInput.Defined(null),
+ optionalInputList = OptionalInput.Defined(null)
+ )
+ assertEquals("""{"optionalInput":null,"optionalInputObject":null,"optionalInputList":null}""", mapper.writeValueAsString(explicitNull))
+ }
+
+ @Test
+ fun `verify defined values are serialized correctly`() {
+ val defined = InputWrapper(
+ optionalInput = OptionalInput.Defined(123),
+ optionalInputObject = OptionalInput.Defined(BasicInput(OptionalInput.Defined("foo"))),
+ optionalInputList = OptionalInput.Defined(listOf("a", "b", "c"))
+ )
+ assertEquals("""{"optionalInput":123,"optionalInputObject":{"name":"foo"},"optionalInputList":["a","b","c"]}""", mapper.writeValueAsString(defined))
+ }
+
+ @Test
+ fun `verify inner undefined values are serialized correctly`() {
+ val nestedUndefined = InputWrapper(optionalInputObject = OptionalInput.Defined(BasicInput(name = OptionalInput.Undefined)))
+ assertEquals("""{"optionalInputObject":{}}""", mapper.writeValueAsString(nestedUndefined))
+ }
+
+ data class InputWrapper(
+ val optionalInput: OptionalInput<Int> = OptionalInput.Undefined,
+ val optionalInputObject: OptionalInput<BasicInput> = OptionalInput.Undefined,
+ val optionalInputList: OptionalInput<List<String>> = OptionalInput.Undefined
+ )
+
+ data class BasicInput(
+ val name: OptionalInput<String> = OptionalInput.Undefined
+ )
+}

clients/graphql-kotlin-client-serialization/build.gradle.kts

@@ -20,7 +20,7 @@ tasks {
  limit {
  counter = "INSTRUCTION"
  value = "COVEREDRATIO"
- minimum = "0.73".toBigDecimal()
+ minimum = "0.77".toBigDecimal()
  }
  }
  }

clients/graphql-kotlin-client-serialization/src/main/kotlin/com/expediagroup/graphql/client/serialization/GraphQLClientKotlinxSerializer.kt

@@ -41,6 +41,7 @@ class GraphQLClientKotlinxSerializer(private val jsonBuilder: JsonBuilder.() ->
  apply(jsonBuilder)
  classDiscriminator = "__typename"
  coerceInputValues = true
+ // encodeDefaults = false // need this for optional
  encodeDefaults = true
  }
 

clients/graphql-kotlin-client-serialization/src/main/kotlin/com/expediagroup/graphql/client/serialization/serializers/AnyKSerializer.kt

@@ -16,6 +16,7 @@
 
 package com.expediagroup.graphql.client.serialization.serializers
 
+import com.expediagroup.graphql.client.serialization.types.OptionalInput
 import kotlinx.serialization.KSerializer
 import kotlinx.serialization.descriptors.SerialDescriptor
 import kotlinx.serialization.descriptors.buildClassSerialDescriptor
@@ -47,30 +48,37 @@ object AnyKSerializer : KSerializer<Any?> {
  override val descriptor: SerialDescriptor = buildClassSerialDescriptor("Any")
 
  override fun serialize(encoder: Encoder, value: Any?) {
- val jsonEncoder = encoder as JsonEncoder
- val jsonElement = serializeAny(value)
- jsonEncoder.encodeJsonElement(jsonElement)
+ serializeAny(value)?.let {
+ val jsonEncoder = encoder as JsonEncoder
+ jsonEncoder.encodeJsonElement(it)
+ }
  }
 
- private fun serializeAny(value: Any?): JsonElement = when (value) {
+ private fun serializeAny(value: Any?): JsonElement? = when (value) {
  null -> JsonNull
+ is OptionalInput.Undefined -> null
+ is OptionalInput.Defined<*> -> serializeAny(value.value)
  is Map<*, *> -> {
- val mapContents = value.entries.associate { mapEntry ->
- mapEntry.key.toString() to serializeAny(mapEntry.value)
- }
+ val mapContents = value.mapNotNull { (key, value) ->
+ serializeAny(value)?.let {
+ key.toString() to it
+ }
+ }.toMap()
  JsonObject(mapContents)
  }
  is List<*> -> {
- val arrayContents = value.map { listEntry -> serializeAny(listEntry) }
+ val arrayContents = value.mapNotNull { listEntry -> serializeAny(listEntry) }
  JsonArray(arrayContents)
  }
  is Number -> JsonPrimitive(value)
  is Boolean -> JsonPrimitive(value)
  is String -> JsonPrimitive(value)
  else -> {
- val contents = value::class.memberProperties.associate { property ->
- property.name to serializeAny(property.getter.call(value))
- }
+ val contents = value::class.memberProperties.mapNotNull { property ->
+ serializeAny(property.getter.call(value))?.let {
+ property.name to it
+ }
+ }.toMap()
  JsonObject(contents)
  }
  }