[generator] filter lambda properties

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/exceptions/InvalidPropertyReturnTypeException.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2022 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.generator.exceptions
+
+import kotlin.reflect.KClass
+import kotlin.reflect.KProperty
+
+/**
+ * Thrown when the schema defines an object property which is a lambda.
+ */
+class InvalidPropertyReturnTypeException(kClass: KClass<*>, property: KProperty<*>) :
+    GraphQLKotlinException("The class $kClass defines $property as a lambda which is currently unsupported")

generator/graphql-kotlin-schema-generator/src/main/kotlin/com/expediagroup/graphql/generator/internal/filters/propertyFilters.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021 Expedia, Inc
+ * Copyright 2022 Expedia, Inc
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,15 +16,18 @@
 
 package com.expediagroup.graphql.generator.internal.filters
 
+import com.expediagroup.graphql.generator.exceptions.InvalidPropertyReturnTypeException
 import com.expediagroup.graphql.generator.internal.extensions.isGraphQLIgnored
 import com.expediagroup.graphql.generator.internal.extensions.isPropertyGraphQLIgnored
 import com.expediagroup.graphql.generator.internal.extensions.isPublic
 import com.expediagroup.graphql.generator.internal.extensions.qualifiedName
 import com.expediagroup.graphql.generator.internal.types.utils.validGraphQLNameRegex
 import kotlin.reflect.KClass
 import kotlin.reflect.KProperty
+import kotlin.reflect.full.isSubtypeOf
 import kotlin.reflect.full.memberProperties
 import kotlin.reflect.jvm.jvmErasure
+import kotlin.reflect.typeOf
 
 private typealias PropertyFilter = (KProperty<*>, KClass<*>) -> Boolean
 
@@ -34,13 +37,21 @@ private val isPropertyPublic: PropertyFilter = { prop, _ -> prop.isPublic() }
 private val isPropertyNotGraphQLIgnored: PropertyFilter = { prop, parentClass -> prop.isPropertyGraphQLIgnored(parentClass).not() }
 private val isNotBlacklistedType: PropertyFilter = { prop, _ -> blacklistTypes.contains(prop.returnType.qualifiedName).not() }
 private val isValidPropertyName: PropertyFilter = { prop, _ -> prop.name.matches(validGraphQLNameRegex) }
+@OptIn(ExperimentalStdlibApi::class)
+private val isNotLambda: PropertyFilter = { prop, parentClass ->
+    if (prop.returnType.isSubtypeOf(typeOf<Function<*>>())) {
+        throw InvalidPropertyReturnTypeException(parentClass, prop)
+    } else {
+        true
+    }
+}
 
 private val isNotIgnoredFromSuperClass: PropertyFilter = { prop, parentClass ->
     val superPropsIgnored = parentClass.supertypes
         .flatMap { superType ->
             superType.jvmErasure.memberProperties
-                .filter { superProp -> basicPropertyFilters.all { it.invoke(superProp, superType::class) } }
                 .filter { it.isGraphQLIgnored() }
+                .filter { superProp -> basicPropertyFilters.all { it.invoke(superProp, superType::class) } }
         }
 
     superPropsIgnored.none { superProp ->
@@ -49,5 +60,5 @@ private val isNotIgnoredFromSuperClass: PropertyFilter = { prop, parentClass ->
     }
 }
 
-private val basicPropertyFilters = listOf(isPropertyPublic, isNotBlacklistedType)
-internal val propertyFilters: List<PropertyFilter> = basicPropertyFilters + isPropertyNotGraphQLIgnored + isNotIgnoredFromSuperClass + isValidPropertyName
+private val basicPropertyFilters = listOf(isPropertyPublic, isNotLambda, isNotBlacklistedType)
+internal val propertyFilters: List<PropertyFilter> = listOf(isPropertyNotGraphQLIgnored) + basicPropertyFilters + isNotIgnoredFromSuperClass + isValidPropertyName

generator/graphql-kotlin-schema-generator/src/test/kotlin/com/expediagroup/graphql/generator/internal/filters/PropertyFiltersTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019 Expedia, Inc
+ * Copyright 2022 Expedia, Inc
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,9 @@
 package com.expediagroup.graphql.generator.internal.filters
 
 import com.expediagroup.graphql.generator.annotations.GraphQLIgnore
+import com.expediagroup.graphql.generator.exceptions.InvalidPropertyReturnTypeException
 import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertThrows
 import kotlin.reflect.KClass
 import kotlin.reflect.KProperty
 import kotlin.test.assertFalse
@@ -35,6 +37,13 @@ internal class PropertyFiltersTest {
         assertFalse(isValidProperty(MyDataClass::ignoredProperty, MyDataClass::class))
         assertFalse(isValidProperty(MyClass::foo, MyClass::class))
         assertFalse(isValidProperty(MyClass::`$invalidPropertyName`, MyClass::class))
+
+        assertThrows<InvalidPropertyReturnTypeException> {
+            isValidProperty(MyClass::lambda, MyClass::class)
+        }
+        assertThrows<InvalidPropertyReturnTypeException> {
+            isValidProperty(MyClass::suspendableLambda, MyClass::class)
+        }
     }
 
     internal data class MyDataClass(
@@ -49,7 +58,10 @@ internal class PropertyFiltersTest {
         val foo: Int
     }
 
-    internal class MyClass : MyInterface {
+    internal class MyClass(
+        val lambda: () -> String,
+        val suspendableLambda: suspend () -> String
+    ) : MyInterface {
 
         val publicProperty: Int = 0
 

generator/graphql-kotlin-schema-generator/src/test/kotlin/com/expediagroup/graphql/generator/internal/types/GenerateObjectTest.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021 Expedia, Inc
+ * Copyright 2022 Expedia, Inc
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,16 +18,19 @@ package com.expediagroup.graphql.generator.internal.types
 
 import com.expediagroup.graphql.generator.annotations.GraphQLDescription
 import com.expediagroup.graphql.generator.annotations.GraphQLDirective
+import com.expediagroup.graphql.generator.annotations.GraphQLIgnore
 import com.expediagroup.graphql.generator.annotations.GraphQLName
 import com.expediagroup.graphql.generator.annotations.GraphQLValidObjectLocations
 import com.expediagroup.graphql.generator.exceptions.InvalidGraphQLNameException
 import com.expediagroup.graphql.generator.exceptions.InvalidObjectLocationException
+import com.expediagroup.graphql.generator.exceptions.InvalidPropertyReturnTypeException
 import graphql.Scalars
 import graphql.introspection.Introspection
 import graphql.schema.GraphQLNonNull
 import graphql.schema.GraphQLObjectType
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertDoesNotThrow
+import org.junit.jupiter.api.assertThrows
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 import kotlin.test.assertNotNull
@@ -66,6 +69,20 @@ class GenerateObjectTest : TypeTestHelper() {
     @GraphQLName("Invalid\$Name")
     class InvalidOutputTypeNameOverride
 
+    data class FooLambda(
+        val foo: () -> String
+    )
+
+    data class SuspendableFooLambda(
+        val foo: suspend () -> String?
+    )
+
+    data class Foo(
+        val foo: String,
+        @GraphQLIgnore val fooLambda: () -> String?,
+        private val fooSuspendable: suspend () -> String?
+    )
+
     @Test
     fun `Test naming`() {
         val result = generateObject(generator, BeHappy::class) as? GraphQLObjectType
@@ -139,4 +156,27 @@ class GenerateObjectTest : TypeTestHelper() {
             generateInputObject(generator, InvalidOutputTypeNameOverride::class)
         }
     }
+
+    @Test
+    fun `Generation of output object will fail if one of the properties is lambda`() {
+        assertThrows<InvalidPropertyReturnTypeException> {
+            generateObject(generator, FooLambda::class)
+        }
+    }
+
+    @Test
+    fun `Generation of output object will fail if one of the properties is suspendable lambda`() {
+        assertThrows<InvalidPropertyReturnTypeException> {
+            generateObject(generator, SuspendableFooLambda::class)
+        }
+    }
+
+    @Test
+    fun `Generation of output objects ignores private or @GraphQLIgnored lambdas `() {
+        val result = generateObject(generator, Foo::class)
+        assertNotNull(result)
+        assertEquals("Foo", result.name)
+        assertEquals(1, result.fieldDefinitions.size)
+        assertEquals("foo", result.fieldDefinitions[0].name)
+    }
 }