Index: trunk/test/unit/org/openstreetmap/josm/gui/dialogs/properties/TaginfoActionTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/dialogs/properties/TaginfoActionTest.java	(revision 16596)
+++ trunk/test/unit/org/openstreetmap/josm/gui/dialogs/properties/TaginfoActionTest.java	(revision 16596)
@@ -0,0 +1,44 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.gui.dialogs.properties;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.openstreetmap.josm.data.osm.Tag;
+import org.openstreetmap.josm.testutils.JOSMTestRules;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+public class TaginfoActionTest {
+
+    /**
+     * Setup test.
+     */
+    @Rule
+    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
+    public JOSMTestRules test = new JOSMTestRules();
+
+    /**
+     * Unit test of {@link TaginfoAction#getTaginfoUrlForTag} and {@link TaginfoAction#getTaginfoUrlForRelationType}
+     */
+    @Test
+    public void testTaginfoUrls() {
+        TaginfoAction action = new TaginfoAction(() -> null, () -> null);
+        assertEquals("https://taginfo.openstreetmap.org/keys/railway", action.getTaginfoUrlForTag(new Tag("railway")));
+        assertEquals("https://taginfo.openstreetmap.org/tags/railway=tram", action.getTaginfoUrlForTag(new Tag("railway", "tram")));
+        assertEquals("https://taginfo.openstreetmap.org/relations/route", action.getTaginfoUrlForRelationType("route"));
+    }
+
+    /**
+     * Unit test of {@link TaginfoAction#toTagHistoryAction()}
+     */
+    @Test
+    public void testTagHistoryUrls() {
+        TaginfoAction action = new TaginfoAction(() -> null, () -> null).toTagHistoryAction();
+        assertEquals("https://taghistory.raifer.tech/#***/railway/", action.getTaginfoUrlForTag(new Tag("railway")));
+        assertEquals("https://taghistory.raifer.tech/#***/railway/tram", action.getTaginfoUrlForTag(new Tag("railway", "tram")));
+        assertNull(action.getTaginfoUrlForRelationType("route"));
+    }
+}