JsonStructureParser fixes

- fix getObject() to work on root object
- fix getObject() to advance parser state
- fix getArray() to work on root array
- fix getArray() to advance parser state

Author: marschall

impl/src/main/java/org/eclipse/parsson/JsonStructureParser.java

@@ -19,6 +19,7 @@
 import jakarta.json.*;
 import jakarta.json.stream.JsonLocation;
 import jakarta.json.stream.JsonParser;
+
 import java.math.BigDecimal;
 import java.util.ArrayDeque;
 import java.util.Deque;
@@ -113,7 +114,10 @@ public JsonArray getArray() {
             throw new IllegalStateException(
                     JsonMessages.PARSER_GETARRAY_ERR(state));
         }
-        return (JsonArray) scopeStack.peek().getJsonValue();
+        JsonArray array = (JsonArray) current.getJsonStructure();
+        // #transition() will pop the stack 
+        this.state = Event.END_ARRAY;
+        return array;
     }
 
     @Override
@@ -122,7 +126,10 @@ public JsonObject getObject() {
             throw new IllegalStateException(
                     JsonMessages.PARSER_GETOBJECT_ERR(state));
         }
-        return (JsonObject) scopeStack.peek().getJsonValue();
+        JsonObject object = (JsonObject) current.getJsonStructure();
+        // #transition() will pop the stack 
+        this.state = Event.END_OBJECT;
+        return object;
     }
 
     @Override
@@ -271,8 +278,19 @@ private static Event getState(JsonValue value) {
     }
 
     private static abstract class Scope implements Iterator {
+
+        private final JsonStructure jsonStructure;
+
+        Scope(JsonStructure jsonStructure) {
+            this.jsonStructure = jsonStructure;
+        }
+
         abstract JsonValue getJsonValue();
 
+        JsonStructure getJsonStructure() {
+            return jsonStructure;
+        }
+
         static Scope createScope(JsonValue value) {
             if (value instanceof JsonArray) {
                 return new ArrayScope((JsonArray)value);
@@ -288,6 +306,7 @@ private static class ArrayScope extends Scope {
         private JsonValue value;
 
         ArrayScope(JsonArray array) {
+            super(array);
             this.it = array.iterator();
         }
 
@@ -320,6 +339,7 @@ private static class ObjectScope extends Scope {
         private String key;
 
         ObjectScope(JsonObject object) {
+            super(object);
             this.it = object.entrySet().iterator();
         }
 

impl/src/test/java/org/eclipse/parsson/tests/JsonParserTest.java

@@ -515,13 +515,13 @@ private void testGetValueStructure(JsonParser parser) {
         JsonValue value = parser.getValue();
         Assertions.assertTrue(value instanceof JsonNumber);
         JsonNumber number = (JsonNumber) value;
-        assertEquals(number.longValueExact(), 1L);
+        Assertions.assertEquals(number.longValueExact(), 1L);
 
         Assertions.assertEquals(Event.VALUE_NUMBER, parser.next());
         value = parser.getValue();
         Assertions.assertTrue(value instanceof JsonNumber);
         number = (JsonNumber) value;
-        assertEquals(number.bigDecimalValue(), new BigDecimal("1.1"));
+        Assertions.assertEquals(number.bigDecimalValue(), new BigDecimal("1.1"));
 
         Assertions.assertEquals(Event.VALUE_TRUE, parser.next());
         value = parser.getValue();
@@ -535,7 +535,7 @@ private void testGetValueStructure(JsonParser parser) {
         value = parser.getValue();
         Assertions.assertTrue(value instanceof JsonString);
         JsonString string = (JsonString) value;
-        assertEquals("aString", string.getString());
+        Assertions.assertEquals("aString", string.getString());
 
         Assertions.assertEquals(Event.VALUE_NULL, parser.next());
         value = parser.getValue();
@@ -545,7 +545,6 @@ private void testGetValueStructure(JsonParser parser) {
         Assertions.assertEquals(Event.START_ARRAY, parser.next());
         JsonArray array = parser.getArray();
         Assertions.assertTrue(array.isEmpty());
-        Assertions.assertEquals(Event.END_ARRAY, parser.next());
 
         Assertions.assertEquals(Event.START_OBJECT, parser.next());
 
@@ -595,11 +594,55 @@ private void testGetValueStructure(JsonParser parser) {
         JsonObject object = parser.getObject();
         Assertions.assertTrue(object.isEmpty());
         Assertions.assertEquals(Event.END_OBJECT, parser.next());
-        Assertions.assertEquals(Event.END_OBJECT, parser.next());
         Assertions.assertEquals(Event.END_ARRAY, parser.next());
         Assertions.assertFalse(parser.hasNext());
     }
 
+    @Test
+    void testGetArrayRoot() {
+        try (JsonParser parser = Json.createParserFactory(null).createParser(
+                Json.createArrayBuilder()
+                    .add(1)
+                    .add(2)
+                    .add(3)
+                    .build())) {
+          testGetArrayRoot(parser);
+        }
+    }
+
+    private void testGetArrayRoot(JsonParser parser) {
+        Assertions.assertEquals(Event.START_ARRAY, parser.next());
+        JsonArray actual = parser.getArray();
+        JsonArray expected = Json.createArrayBuilder()
+                .add(1)
+                .add(2)
+                .add(3)
+                .build();
+        Assertions.assertEquals(expected, actual);
+        Assertions.assertEquals(Event.END_ARRAY, parser.currentEvent());
+        Assertions.assertFalse(parser.hasNext());
+    }
+    
+    @Test
+    void testGetObjectRoot() {
+      try (JsonParser parser = Json.createParserFactory(null).createParser(
+              Json.createObjectBuilder()
+              .add("key1", "value1")
+              .build())) {
+        testGetObjectRoot(parser);
+      }
+    }
+    
+    private void testGetObjectRoot(JsonParser parser) {
+      Assertions.assertEquals(Event.START_OBJECT, parser.next());
+      JsonObject actual = parser.getObject();
+      JsonObject expected = Json.createObjectBuilder()
+              .add("key1", "value1")
+              .build();
+      Assertions.assertEquals(expected, actual);
+      Assertions.assertEquals(Event.END_OBJECT, parser.currentEvent());
+      Assertions.assertFalse(parser.hasNext());
+    }
 
     @Test
     void testNestedArrayReader() {