Index: trunk/test/unit/org/openstreetmap/josm/gui/dialogs/properties/RecentTagCollectionTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/dialogs/properties/RecentTagCollectionTest.java	(revision 9939)
+++ trunk/test/unit/org/openstreetmap/josm/gui/dialogs/properties/RecentTagCollectionTest.java	(revision 9939)
@@ -0,0 +1,58 @@
+// 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.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+import java.util.Collections;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.openstreetmap.josm.JOSMFixture;
+import org.openstreetmap.josm.data.osm.Tag;
+import org.openstreetmap.josm.data.preferences.CollectionProperty;
+
+/**
+ * Unit tests of {@link RecentTagCollection} class.
+ */
+public class RecentTagCollectionTest {
+
+    /**
+     * Setup tests
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() {
+        JOSMFixture.createUnitTestFixture().init();
+    }
+
+    /**
+     * Performs various tests on a {@link RecentTagCollection}.
+      */
+    @Test
+    public void test() {
+        final RecentTagCollection recentTags = new RecentTagCollection(2);
+        assertTrue(recentTags.isEmpty());
+
+        final Tag foo = new Tag("name", "foo");
+        final Tag bar = new Tag("name", "bar");
+        final Tag baz = new Tag("name", "baz");
+        recentTags.add(foo);
+        recentTags.add(bar);
+        assertFalse(recentTags.isEmpty());
+        assertEquals(Arrays.asList(foo, bar), recentTags.toList());
+        recentTags.add(foo);
+        assertEquals(Arrays.asList(bar, foo), recentTags.toList());
+        recentTags.add(baz);
+        assertEquals(Arrays.asList(foo, baz), recentTags.toList());
+
+        final CollectionProperty pref = new CollectionProperty("properties.recent-tags", Collections.<String>emptyList());
+        recentTags.saveToPreference(pref);
+        assertEquals(Arrays.asList("name", "foo", "name", "baz"), pref.get());
+        pref.put(Arrays.asList("key=", "=value"));
+        recentTags.loadFromPreference(pref);
+        assertEquals(Collections.singletonList(new Tag("key=", "=value")), recentTags.toList());
+
+    }
+}