Index: trunk/test/unit/org/openstreetmap/josm/gui/autofilter/AutoFilterManagerTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/autofilter/AutoFilterManagerTest.java	(revision 12407)
+++ trunk/test/unit/org/openstreetmap/josm/gui/autofilter/AutoFilterManagerTest.java	(revision 12407)
@@ -0,0 +1,49 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.gui.autofilter;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Arrays;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.function.Consumer;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.openstreetmap.josm.data.osm.OsmPrimitive;
+import org.openstreetmap.josm.data.osm.OsmUtils;
+import org.openstreetmap.josm.testutils.JOSMTestRules;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+/**
+ * Unit tests of {@link AutoFilterManager} class.
+ */
+public class AutoFilterManagerTest {
+
+    /**
+     * Setup tests
+     */
+    @Rule
+    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
+    public JOSMTestRules test = new JOSMTestRules();
+
+    /**
+     * Unit test of {@link AutoFilterManager#getTagValuesConsumer}.
+     */
+    @Test
+    public void testTagValuesConsumer() {
+        Set<String> values = new TreeSet<>();
+        Consumer<OsmPrimitive> consumer = AutoFilterManager.getTagValuesConsumer("level", values);
+        Arrays.asList(
+                OsmUtils.createPrimitive("way level=-4--5"),
+                OsmUtils.createPrimitive("way level=-2"),
+                OsmUtils.createPrimitive("node level=0"),
+                OsmUtils.createPrimitive("way level=1"),
+                OsmUtils.createPrimitive("way level=2;3"),
+                OsmUtils.createPrimitive("way level=6-9"),
+                OsmUtils.createPrimitive("way level=10;12-13")
+                ).forEach(consumer);
+        assertEquals(new TreeSet<>(Arrays.asList("-5", "-4", "-2", "0", "1", "2", "3", "6", "7", "8", "9", "10", "12", "13")), values);
+    }
+}