Fix #24512: unset tag operation from MR was not supported

Signed-off-by: Taylor Smock <smocktaylor@gmail.com>

Author: tsmock

src/main/java/org/openstreetmap/josm/plugins/maproulette/api/parsers/TaskParser.java

@@ -12,6 +12,7 @@
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Base64;
+import java.util.Collections;
 import java.util.Map;
 import java.util.stream.Collectors;
 
@@ -170,6 +171,12 @@ private static Object parseCooperativeWork(JsonObject object) {
                                             Map.Entry::getKey, entry -> ((JsonString) entry.getValue()).getString()));
                             modifies.add(new ElementUpdate(id.getUniqueId(), id.getType(), Integer.MIN_VALUE,
                                     new ElementTagChange(elemData, new String[0])));
+                        } else if ("unsetTags".equals(elemType)) {
+                            final var elemData = elemOp.getJsonArray("data").stream()
+                                    .filter(JsonString.class::isInstance).map(JsonString.class::cast)
+                                    .map(JsonString::getString).toArray(String[]::new);
+                            modifies.add(new ElementUpdate(id.getUniqueId(), id.getType(), Integer.MIN_VALUE,
+                                    new ElementTagChange(Collections.emptyMap(), elemData)));
                         } else {
                             throw new IllegalArgumentException(object.toString());
                         }

src/test/resources/__files/api/v2/task/135045992/start

@@ -98,6 +98,12 @@
                 "FMMP_modified": "yes"
               },
               "operation": "setTags"
+            },
+            {
+              "data": [
+                "source"
+              ],
+              "operation":"unsetTags"
             }
           ]
         },

src/test/unit/org/openstreetmap/josm/plugins/maproulette/api/parsers/TaskParserTest.java

@@ -9,6 +9,7 @@
 import static org.openstreetmap.josm.plugins.maproulette.util.RecordAssertion.assertRecordsEqual;
 
 import java.time.Instant;
+import java.util.Collections;
 import java.util.Map;
 
 import org.junit.jupiter.api.Test;
@@ -40,9 +41,12 @@ void testTaskParsing135045992() {
                 Instant.parse("2022-08-06T15:23:36.531Z"), 24092, "", new Point(36.0819446365856, -119.104608317353),
                 task.geometries(),
                 new OSMChange(new ElementCreate[0],
-                        new ElementUpdate[] { new ElementUpdate(131190351L, OsmPrimitiveType.WAY, Integer.MIN_VALUE,
-                                new ElementTagChange(Map.of("landuse", "farmland", "FMMP_modified", "yes"),
-                                        new String[0])) }),
+                        new ElementUpdate[] {
+                                new ElementUpdate(131190351L, OsmPrimitiveType.WAY, Integer.MIN_VALUE,
+                                        new ElementTagChange(Map.of("landuse", "farmland", "FMMP_modified", "yes"),
+                                                new String[0])),
+                                new ElementUpdate(131190351L, OsmPrimitiveType.WAY, Integer.MIN_VALUE,
+                                        new ElementTagChange(Collections.emptyMap(), new String[] { "source" })) }),
                 TaskStatus.CREATED, null, null, null,
                 new TaskReviewFields(null, null, null, null, null, null, null, null, null, null), 0, -1L, null, null,
                 false, null, "");

src/test/unit/org/openstreetmap/josm/plugins/maproulette/util/RecordAssertion.java

@@ -53,13 +53,13 @@ public static <T extends Record> void assertRecordsEqual(T expected, T actual, S
                 final var method = component.getAccessor();
                 final var expectedObj = method.invoke(expected);
                 final var actualObj = method.invoke(actual);
-                if (expectedObj instanceof Record && actualObj instanceof Record
-                        && expectedObj.getClass().equals(actualObj.getClass())) {
+                final var sameClass = actualObj != null && expectedObj != null
+                        && expectedObj.getClass().equals(actualObj.getClass());
+                if (expectedObj instanceof Record && actualObj instanceof Record && sameClass) {
                     executableList.add(
                             () -> assertRecordsEqual((Record) expectedObj, (Record) actualObj, component.getName()));
                 } else if (expectedObj instanceof Object[] expectedArray && actualObj instanceof Object[] actualArray) {
-                    if (expectedObj.getClass().getComponentType().isRecord()
-                            && expectedObj.getClass().equals(actualObj.getClass())) {
+                    if (expectedObj.getClass().getComponentType().isRecord() && sameClass) {
                         executableList
                                 .add(() -> assertEquals(expectedArray.length, actualArray.length, component.getName()));
                         if (expectedArray.length == actualArray.length) {