add configuration to disable instrospection

kgraphql/src/main/kotlin/com/apurebase/kgraphql/configuration/SchemaConfiguration.kt

@@ -19,6 +19,7 @@ data class SchemaConfiguration(
 
         val executor: Executor,
         val timeout: Long?,
+        val introspection: Boolean = true,
         val plugins: MutableMap<KClass<*>, Any>
 ) {
         @Suppress("UNCHECKED_CAST")

kgraphql/src/main/kotlin/com/apurebase/kgraphql/schema/DefaultSchema.kt

@@ -44,6 +44,10 @@ class DefaultSchema (
             ?.let { VariablesJson.Defined(configuration.objectMapper, variables) }
             ?: VariablesJson.Empty()
 
+        if (!configuration.introspection && request.isIntrospection()) {
+            throw GraphQLError("GraphQL introspection is not allowed")
+        }
+
         val document = Parser(request).parseDocument()
 
         val executor = options.executor?.let(this@DefaultSchema::getExecutor) ?: defaultRequestExecutor
@@ -55,6 +59,8 @@ class DefaultSchema (
         )
     }
 
+    private fun String.isIntrospection() = this.contains("__schema") || this.contains("__type")
+
     override fun typeByKClass(kClass: KClass<*>): Type? = model.queryTypes[kClass]
 
     override fun typeByKType(kType: KType): Type? = typeByKClass(kType.jvmErasure)

kgraphql/src/main/kotlin/com/apurebase/kgraphql/schema/dsl/SchemaConfigurationDSL.kt

@@ -20,6 +20,7 @@ open class SchemaConfigurationDSL {
     var wrapErrors: Boolean = true
     var executor: Executor = Executor.Parallel
     var timeout: Long? = null
+    var introspection: Boolean = true
 
     private val plugins: MutableMap<KClass<*>, Any> = mutableMapOf()
 
@@ -42,6 +43,7 @@ open class SchemaConfigurationDSL {
             wrapErrors,
             executor,
             timeout,
+            introspection,
             plugins
         )
     }

kgraphql/src/test/kotlin/com/apurebase/kgraphql/schema/SchemaBuilderTest.kt

@@ -337,6 +337,28 @@ class SchemaBuilderTest {
         assertThat(introspection.extract<String>("data/__schema/queryType/fields[0]/args[0]/description"), equalTo(expectedDescription))
     }
 
+    @Test
+    fun `introspections query should be disabled`(){
+        val expectedDescription = "Int Argument"
+        val expectedDefaultValue = 33
+        val schema = defaultSchema {
+
+            configure {
+                introspection = false
+            }
+
+            query("data"){
+                resolver { int: Int -> int }.withArgs {
+                    arg <Int> { name = "int"; defaultValue = expectedDefaultValue; description = expectedDescription }
+                }
+            }
+        }
+
+        expect<GraphQLError> {
+            schema.executeBlocking("{__schema{queryType{fields{name, args{name, description, defaultValue}}}}}")
+        }
+    }
+
     @Test
     @Suppress("UNUSED_ANONYMOUS_PARAMETER")
     fun `arg name must match exactly one of type property`(){