Applied Directives now only show argument values IF there is a value set. This is a better reflection of the type intentions (graphql-java#2367)

bbakerman · web-flow · commit 1a1070872d67 · 2021-06-01T14:40:23.000+10:00
```
_DirectiveArgument {
   name : String!
   value : String!
}
```
diff --git a/src/main/java/graphql/introspection/IntrospectionWithDirectivesSupport.java b/src/main/java/graphql/introspection/IntrospectionWithDirectivesSupport.java
@@ -5,6 +5,7 @@
 import graphql.PublicSpi;
 import graphql.execution.ValuesResolver;
 import graphql.language.AstPrinter;
+import graphql.language.Node;
 import graphql.schema.DataFetcher;
 import graphql.schema.GraphQLArgument;
 import graphql.schema.GraphQLCodeRegistry;
@@ -191,16 +192,15 @@ private GraphQLObjectType addAppliedDirectives(GraphQLObjectType originalType, G
         };
         DataFetcher<?> argsDF = env -> {
             final GraphQLDirective directive = env.getSource();
-            return directive.getArguments();
+            // we only show directive arguments that have values set on them
+            return directive.getArguments().stream()
+                    .filter(arg -> arg.getArgumentValue().isSet());
         };
         DataFetcher<?> argValueDF = env -> {
             final GraphQLArgument argument = env.getSource();
-            if (argument.hasSetValue()) {
-                InputValueWithState value = argument.getArgumentValue();
-                return AstPrinter.printAst(ValuesResolver.valueToLiteral(value, argument.getType()));
-            } else {
-                return null;
-            }
+            InputValueWithState value = argument.getArgumentValue();
+            Node<?> literal = ValuesResolver.valueToLiteral(value, argument.getType());
+            return AstPrinter.printAst(literal);
         };
         codeRegistry.dataFetcher(coordinates(objectType, "appliedDirectives"), df);
         codeRegistry.dataFetcher(coordinates(appliedDirectiveType, "args"), argsDF);
diff --git a/src/test/java/graphql/introspection/IntrospectionWithDirectivesSupportTest.groovy b/src/test/java/graphql/introspection/IntrospectionWithDirectivesSupportTest.groovy
@@ -2,27 +2,25 @@ package graphql.introspection
 
 import graphql.GraphQL
 import graphql.TestUtil
-import graphql.schema.idl.SchemaPrinter
 import spock.lang.Specification
 
 class IntrospectionWithDirectivesSupportTest extends Specification {
 
-    def printer = new SchemaPrinter(SchemaPrinter.Options.defaultOptions().includeIntrospectionTypes(true))
-
     def "can find directives in introspection"() {
         def sdl = '''
             directive @example( argName : String = "default") on OBJECT | FIELD_DEFINITION | INPUT_OBJECT | INPUT_FIELD_DEFINITION | SCHEMA
             directive @secret( argName : String = "secret") on OBJECT
+            directive @noDefault( arg1 : String, arg2 : String) on OBJECT
             
             schema @example(argName : "onSchema") {
                 query : Query
             }
             
-            type Query @example(argName : "onQuery") {
+            type Query @example(argName : "onQuery") @noDefault(arg1 : "set") {
                 hello : Hello @deprecated
             }
             
-            type Hello @example {
+            type Hello @example @noDefault {
                 world : String @deprecated
             }
             
@@ -33,9 +31,6 @@ class IntrospectionWithDirectivesSupportTest extends Specification {
 
         def schema = TestUtil.schema(sdl)
         schema = new IntrospectionWithDirectivesSupport().apply(schema)
-
-        println printer.print(schema)
-
         def graphql = GraphQL.newGraphQL(schema).build()
 
         def query = '''
@@ -94,15 +89,21 @@ class IntrospectionWithDirectivesSupportTest extends Specification {
 
         def schemaType = er.data["__schema"]
 
-        schemaType["directives"] == [[name: "include"], [name: "skip"], [name: "example"], [name: "secret"], [name: "deprecated"], [name: "specifiedBy"]]
+        schemaType["directives"] == [[name: "include"], [name: "skip"], [name: "example"], [name: "secret"], [name: "noDefault"], [name: "deprecated"], [name: "specifiedBy"]]
 
         schemaType["appliedDirectives"] == [[name: "example", args: [[name: "argName", value: '"onSchema"']]]]
 
         def queryType = er.data["__schema"]["types"].find({ type -> (type["name"] == "Query") })
-        queryType["appliedDirectives"] == [[name: "example", args: [[name: "argName", value: '"onQuery"']]]]
+        queryType["appliedDirectives"] == [
+                [name: "example", args: [[name: "argName", value: '"onQuery"']]],
+                [name: "noDefault", args: [[name: "arg1", value: '"set"']]]
+        ]
 
         def helloType = er.data["__schema"]["types"].find({ type -> (type["name"] == "Hello") })
-        helloType["appliedDirectives"] == [[name: "example", args: [[name: "argName", value: '"default"']]]]
+        helloType["appliedDirectives"] == [
+                [name: "example", args: [[name: "argName", value: '"default"']]],
+                [name: "noDefault", args: []] // always empty list
+        ]
 
         def worldField = helloType["fields"].find({ type -> (type["name"] == "world") })
         worldField["appliedDirectives"] == [[name: 'deprecated', args: [[name: 'reason', value: '"No longer supported"']]]]
