This allows circular types to be applied to. It fixes a StackOverflow bug (#34)

Author: bbakerman

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

@@ -65,7 +65,7 @@ public boolean appliesTo(GraphQLFieldDefinition fieldDefinition, GraphQLFieldsCo
     @Override
     public boolean appliesTo(GraphQLArgument argument, GraphQLFieldDefinition fieldDefinition, GraphQLFieldsContainer fieldsContainer) {
 
-        boolean suitable = DirectivesAndTypeWalker.isSuitable(argument, (inputType, directive) -> {
+        boolean suitable = new DirectivesAndTypeWalker().isSuitable(argument, (inputType, directive) -> {
             boolean hasNamedDirective = directive.getName().equals(this.getName());
             if (hasNamedDirective) {
                 inputType = Util.unwrapNonNull(inputType);

src/main/java/graphql/validation/util/DirectivesAndTypeWalker.java

@@ -8,34 +8,45 @@
 import graphql.schema.GraphQLInputObjectType;
 import graphql.schema.GraphQLInputType;
 import graphql.schema.GraphQLList;
+import graphql.schema.GraphQLTypeUtil;
 
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.BiFunction;
 
 @Internal
 public class DirectivesAndTypeWalker {
 
-    public static boolean isSuitable(GraphQLArgument argument, BiFunction<GraphQLInputType, GraphQLDirective, Boolean> isSuitable) {
+    private final Map<String, Boolean> seenTypes = new HashMap<>();
+
+    public boolean isSuitable(GraphQLArgument argument, BiFunction<GraphQLInputType, GraphQLDirective, Boolean> isSuitable) {
         GraphQLInputType inputType = argument.getType();
         List<GraphQLDirective> directives = argument.getDirectives();
         return walkInputType(inputType, directives, isSuitable);
     }
 
-    private static boolean walkInputType(GraphQLInputType inputType, List<GraphQLDirective> directives, BiFunction<GraphQLInputType, GraphQLDirective, Boolean> isSuitable) {
+    private boolean walkInputType(GraphQLInputType inputType, List<GraphQLDirective> directives, BiFunction<GraphQLInputType, GraphQLDirective, Boolean> isSuitable) {
+        String typeName = GraphQLTypeUtil.unwrapAll(inputType).getName();
         GraphQLInputType unwrappedInputType = Util.unwrapNonNull(inputType);
         for (GraphQLDirective directive : directives) {
             if (isSuitable.apply(unwrappedInputType, directive)) {
-                return true;
+                return seen(typeName,true);
             }
         }
         if (unwrappedInputType instanceof GraphQLInputObjectType) {
             GraphQLInputObjectType inputObjType = (GraphQLInputObjectType) unwrappedInputType;
+            if (seenTypes.containsKey(typeName)) {
+                return seenTypes.get(typeName);
+            }
+            seen(typeName,false);
+
             for (GraphQLInputObjectField inputField : inputObjType.getFieldDefinitions()) {
                 inputType = inputField.getType();
                 directives = inputField.getDirectives();
 
                 if (walkInputType(inputType, directives, isSuitable)) {
-                    return true;
+                    return seen(typeName,true);
                 }
             }
         }
@@ -44,11 +55,16 @@ private static boolean walkInputType(GraphQLInputType inputType, List<GraphQLDir
             if (innerListType instanceof GraphQLDirectiveContainer) {
                 directives = ((GraphQLDirectiveContainer) innerListType).getDirectives();
                 if (walkInputType(innerListType, directives, isSuitable)) {
-                    return true;
+                    return seen(typeName,true);
                 }
             }
         }
-        return false;
+        return seen(typeName,false);
+    }
+
+    private boolean seen(String typeName, boolean flag) {
+        seenTypes.put(typeName, flag);
+        return flag;
     }
 
 }

src/test/groovy/graphql/validation/rules/ValidationRulesTest.groovy

@@ -3,9 +3,11 @@ package graphql.validation.rules
 import graphql.GraphQL
 import graphql.execution.DataFetcherResult
 import graphql.schema.DataFetcher
+import graphql.schema.DataFetchingEnvironment
 import graphql.schema.idl.RuntimeWiring
 import graphql.validation.TestUtil
 import graphql.validation.constraints.DirectiveConstraints
+import graphql.validation.schemawiring.ValidationSchemaWiring
 import spock.lang.Specification
 
 import static graphql.schema.idl.TypeRuntimeWiring.newTypeWiring
@@ -78,4 +80,74 @@ class ValidationRulesTest extends Specification {
         er.errors[2].message == "/cars/filter/model size must be between 0 and 10"
         er.errors[2].path == ["cars"]
     }
+
+    def "issue 17 - type references handled"() {
+
+        def directiveRules = DirectiveConstraints.newDirectiveConstraints().build()
+
+        def sdl = '''
+
+            ''' + directiveRules.directivesSDL + '''
+
+           input NameRequest {
+	         # The title associated to the name
+            title: String @Size(min : 1, max : 1)
+	        # The given name
+	        givenName: String! @Size(min : 1, max : 1)
+	        # Middle Name
+   	        middleName: String
+   	        # Last Name
+   	        surName: String!
+   	        
+   	        # recursion
+   	        inner : NameRequest
+   	        
+   	        innerList : [NameRequest!]
+          }
+
+            type Query {
+                request( arg : NameRequest!) : String
+            }
+        '''
+
+        ValidationRules validationRules = ValidationRules.newValidationRules()
+                .onValidationErrorStrategy(OnValidationErrorStrategy.RETURN_NULL).build()
+        def validationWiring = new ValidationSchemaWiring(validationRules)
+
+        DataFetcher df = { DataFetchingEnvironment env ->
+            return "OK"
+        }
+
+        def runtime = RuntimeWiring.newRuntimeWiring()
+                .type(newTypeWiring("Query").dataFetcher("request", df))
+                .directiveWiring(validationWiring)
+                .build()
+        def graphQLSchema = TestUtil.schema(sdl, runtime)
+        def graphQL = GraphQL.newGraphQL(graphQLSchema).build()
+
+        when:
+
+        def er = graphQL.execute('''
+            {
+                request (
+                    arg : { 
+                        title : "Mr BRAD", givenName : "BRADLEY" , surName : "BAKER" 
+                        inner : { title : "Mr BRAD", givenName : "BRADLEY" , surName : "BAKER" }
+                        innerList : [ { title : "Mr BRAD", givenName : "BRADLEY" , surName : "BAKER" } ]
+                    }
+                )
+            }
+        ''')
+        then:
+        er != null
+        er.data["request"] == null
+        er.errors.size() == 6
+
+        er.errors[0].getMessage() == "/request/arg/givenName size must be between 1 and 1"
+        er.errors[1].getMessage() == "/request/arg/inner/givenName size must be between 1 and 1"
+        er.errors[2].getMessage() == "/request/arg/inner/title size must be between 1 and 1"
+        er.errors[3].getMessage() == "/request/arg/innerList[0]/givenName size must be between 1 and 1"
+        er.errors[4].getMessage() == "/request/arg/innerList[0]/title size must be between 1 and 1"
+        er.errors[5].getMessage() == "/request/arg/title size must be between 1 and 1"
+    }
 }

src/test/groovy/graphql/validation/util/DirectivesAndTypeWalkerTest.groovy

@@ -0,0 +1,32 @@
+package graphql.validation.util
+
+
+import graphql.schema.GraphQLObjectType
+import graphql.validation.TestUtil
+import spock.lang.Specification
+
+class DirectivesAndTypeWalkerTest extends Specification {
+
+    def "can walk self referencing types"() {
+        def sdl = """
+            input TestInput @deprecated {
+                name : String
+                list : [TestInput]
+                self : TestInput
+            }
+            
+            type Query {
+                f(arg : TestInput) : String
+            }
+        """
+
+        def schema = TestUtil.schema(sdl)
+        def arg = (schema.getType("Query") as GraphQLObjectType).getFieldDefinition("f").getArgument("arg")
+        def callback = { t, d -> true }
+        when:
+        def suitable = new DirectivesAndTypeWalker().isSuitable(arg, callback)
+
+        then:
+        suitable
+    }
+}