Fix a case when List NonNullType has a default value #177 (#179)

Author: kobylynskyi

src/main/java/com/kobylynskyi/graphql/codegen/mapper/DefaultValueMapper.java

@@ -31,7 +31,7 @@ public static String map(MappingContext mappingContext, Value<?> defaultValue, T
             return mapObject((ObjectValue) defaultValue);
         }
         if (defaultValue instanceof ArrayValue) {
-            return mapArray(mappingContext, (ArrayValue) defaultValue, graphQLType);
+            return mapArray(mappingContext, graphQLType, (ArrayValue) defaultValue);
         }
         // no default value, or not a known type
         return null;
@@ -74,17 +74,20 @@ private static String mapObject(ObjectValue defaultValue) {
         return null;
     }
 
-    private static String mapArray(MappingContext mappingContext, ArrayValue defaultValue, Type<?> graphQLType) {
-        if (!(graphQLType instanceof ListType)) {
-            throw new IllegalArgumentException("Unexpected array default value for non-list type");
+    private static String mapArray(MappingContext mappingContext, Type<?> graphQLType, ArrayValue defaultValue) {
+        if (graphQLType instanceof NonNullType) {
+            return mapArray(mappingContext, ((NonNullType) graphQLType).getType(), defaultValue);
         }
-        List<Value> values = defaultValue.getValues();
-        if (values.isEmpty()) {
-            return "java.util.Collections.emptyList()";
+        if (graphQLType instanceof ListType) {
+            List<Value> values = defaultValue.getValues();
+            if (values.isEmpty()) {
+                return "java.util.Collections.emptyList()";
+            }
+            Type<?> elementType = ((ListType) graphQLType).getType();
+            return values.stream()
+                    .map(v -> map(mappingContext, v, elementType))
+                    .collect(Collectors.joining(", ", "java.util.Arrays.asList(", ")"));
         }
-        Type<?> elementType = ((ListType) graphQLType).getType();
-        return values.stream()
-                .map(v -> map(mappingContext, v, elementType))
-                .collect(Collectors.joining(", ", "java.util.Arrays.asList(", ")"));
+        throw new IllegalArgumentException("Unexpected array default value for non-list type");
     }
 }

src/test/resources/expected-classes/defaults/InputWithDefaults.java.txt

@@ -17,6 +17,7 @@ public class InputWithDefaults implements java.io.Serializable {
     private SomeObject objectWithNonNullDefault;
     private java.util.List<Integer> intList = java.util.Arrays.asList(1, 2, 3);
     private java.util.List<Integer> intListEmptyDefault = java.util.Collections.emptyList();
+    @javax.validation.constraints.NotNull
     private java.util.List<SomeObject> objectListEmptyDefault = java.util.Collections.emptyList();
 
     public InputWithDefaults() {

src/test/resources/expected-classes/defaults/InputWithDefaultsTO.java.txt

@@ -17,6 +17,7 @@ public class InputWithDefaultsTO implements java.io.Serializable {
     private SomeObjectTO objectWithNonNullDefault;
     private java.util.List<Integer> intList = java.util.Arrays.asList(1, 2, 3);
     private java.util.List<Integer> intListEmptyDefault = java.util.Collections.emptyList();
+    @javax.validation.constraints.NotNull
     private java.util.List<SomeObjectTO> objectListEmptyDefault = java.util.Collections.emptyList();
 
     public InputWithDefaultsTO() {

src/test/resources/schemas/defaults.graphqls

@@ -11,7 +11,7 @@ input InputWithDefaults {
     objectWithNonNullDefault: SomeObject = { name: "Bob" }
     intList: [Int] = [1, 2, 3]
     intListEmptyDefault: [Int] = []
-    objectListEmptyDefault: [SomeObject] = []
+    objectListEmptyDefault: [SomeObject]! = []
 }
 
 input SomeObject {