revert small change

src/main/java/graphql/validation/constraints/AbstractDirectiveConstraint.java

@@ -112,6 +112,11 @@ public boolean appliesTo(GraphQLArgument argument, GraphQLFieldDefinition fieldD
     public List<GraphQLError> runValidation(ValidationEnvironment validationEnvironment) {
         Object validatedValue = validationEnvironment.getValidatedValue();
 
+        // output fields are special
+        if (validationEnvironment.getValidatedElement() == FIELD) {
+            return runValidationImpl(validationEnvironment);
+        }
+
         //
         // all the directives validation code does NOT care for NULL ness since the graphql engine covers that.
         // eg a @NonNull validation directive makes no sense in graphql like it might in Java
@@ -120,11 +125,6 @@ public List<GraphQLError> runValidation(ValidationEnvironment validationEnvironm
             return Collections.emptyList();
         }
 
-        // output fields are special
-        if (validationEnvironment.getValidatedElement() == FIELD) {
-            return runValidationImpl(validationEnvironment);
-        }
-
         GraphQLInputType inputType = Util.unwrapNonNull(validationEnvironment.getValidatedType());
         validationEnvironment = validationEnvironment.transform(b -> b.validatedType(inputType));
 

src/test/groovy/graphql/validation/constraints/standard/ExpressionConstraintTest.groovy

@@ -11,9 +11,6 @@ class ExpressionConstraintTest extends BaseConstraintTestSupport {
 
     @Unroll
     def "expression constraints on a field"() {
-        // TODO - is this useful? Those tests don't pass anymore because `validatedValue` is null.
-        // Those also validate the arguments, even it the directive is on the field. An alternative for the user could be to wrap the arguments in another abject and put the directive on that wrapped type.
-
         DirectiveConstraint ruleUnderTest = new ExpressionConstraint()
 
         expect:
@@ -31,7 +28,7 @@ class ExpressionConstraintTest extends BaseConstraintTestSupport {
 
         fieldDeclaration                                     | args        | expectedMessage
         'field( first : Int, last : Int) : ID ' + relayCheck | [first: 10] | ""
-//        'field( first : Int, last : Int) : ID ' + relayCheck | [first: 10, last: 20] | "Expression;path=/field;val:null;\t"
+        'field( first : Int, last : Int) : ID ' + relayCheck | [first: 10, last: 20] | "Expression;path=/field;val:null;\t"
     }