Add warning and test

Author: oryan-block

src/main/kotlin/graphql/kickstart/tools/resolver/MethodFieldResolver.kt

@@ -14,6 +14,7 @@ import graphql.schema.DataFetcher
 import graphql.schema.DataFetchingEnvironment
 import graphql.schema.GraphQLTypeUtil.isScalar
 import kotlinx.coroutines.future.future
+import org.slf4j.LoggerFactory
 import java.lang.reflect.Method
 import java.util.*
 import kotlin.coroutines.intrinsics.suspendCoroutineUninterceptedOrReturn
@@ -31,6 +32,8 @@ internal class MethodFieldResolver(
     val method: Method
 ) : FieldResolver(field, search, options, search.type) {
 
+    private val log = LoggerFactory.getLogger(javaClass)
+
     private val additionalLastArgument =
         try {
             (method.kotlinFunction?.valueParameters?.size
@@ -97,8 +100,15 @@ internal class MethodFieldResolver(
             when (this.method.parameterTypes.last()) {
                 null -> throw ResolverError("Expected at least one argument but got none, this is most likely a bug with graphql-java-tools")
                 options.contextClass -> args.add { environment ->
-                    environment.graphQlContext[options.contextClass]
-                        ?: environment.getContext() // TODO: remove deprecated use in next major release
+                    val context: Any? = environment.graphQlContext[options.contextClass]
+                    if (context != null) {
+                        context
+                    } else {
+                        log.warn("Generic context class has been deprecated by graphql-java. " +
+                            "To continue using a custom context class as the last parameter in resolver methods " +
+                            "please insert it into the new GraphQLContext class when building the ExecutionInput.")
+                        environment.getContext() // TODO: remove deprecated use in next major release
+                    }
                 }
                 GraphQLContext::class.java -> args.add { environment -> environment.graphQlContext }
                 else -> args.add { environment -> environment }

src/test/kotlin/graphql/kickstart/tools/MethodFieldResolverDataFetcherTest.kt

@@ -197,6 +197,20 @@ class MethodFieldResolverDataFetcherTest {
         assertEquals(resolver.get(createEnvironment(DataClass(), context = context)), true)
     }
 
+    @Test
+    fun `data fetcher passes custom context if method has extra argument and custom context is specified as part of GraphQLContext`() {
+        val customContext = ContextClass()
+        val context = GraphQLContext.of(mapOf(ContextClass::class.java to customContext))
+        val options = SchemaParserOptions.newOptions().contextClass(ContextClass::class).build()
+        val resolver = createFetcher("active", options = options, resolver = object : GraphQLResolver<DataClass> {
+            fun isActive(dataClass: DataClass, ctx: ContextClass): Boolean {
+                return ctx == customContext
+            }
+        })
+
+        assertEquals(resolver.get(createEnvironment(DataClass(), context = context)), true)
+    }
+
     @Test
     fun `data fetcher marshalls input object if required`() {
         val name = "correct name"