Index: trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/FunctionsTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/FunctionsTest.java	(revision 15246)
+++ trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/FunctionsTest.java	(revision 15246)
@@ -0,0 +1,91 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.gui.mappaint.mapcss;
+
+import static org.junit.Assert.assertEquals;
+import static org.openstreetmap.josm.data.osm.OsmPrimitiveType.NODE;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.openstreetmap.josm.TestUtils;
+import org.openstreetmap.josm.data.osm.OsmPrimitive;
+import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
+import org.openstreetmap.josm.data.osm.User;
+import org.openstreetmap.josm.gui.mappaint.Environment;
+import org.openstreetmap.josm.testutils.JOSMTestRules;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+/**
+ * Unit tests of {@link Functions}.
+ */
+public class FunctionsTest {
+
+    /**
+     * Setup rule
+     */
+    @Rule
+    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
+    public JOSMTestRules test = new JOSMTestRules();
+
+    private static class EnvBuilder {
+        private final OsmPrimitive osm;
+
+        EnvBuilder(OsmPrimitiveType type) {
+            switch (type) {
+                case NODE : osm = TestUtils.newNode(""); break;
+                case WAY : osm = TestUtils.newWay(""); break;
+                case RELATION : osm = TestUtils.newRelation(""); break;
+                default: throw new IllegalArgumentException();
+            }
+        }
+
+        EnvBuilder setUser(User user) {
+            osm.setUser(user);
+            return this;
+        }
+
+        Environment build() {
+            return new Environment(osm);
+        }
+    }
+
+    /**
+     * Unit test of {@link Functions#osm_user_name}.
+     */
+    @Test
+    public void testOsmUserName() {
+        assertEquals("<anonymous>", Functions.osm_user_name(new EnvBuilder(NODE).setUser(User.getAnonymous()).build()));
+    }
+
+    /**
+     * Unit test of {@link Functions#osm_user_id}.
+     */
+    @Test
+    public void testOsmUserId() {
+        assertEquals(-1, Functions.osm_user_id(new EnvBuilder(NODE).setUser(User.getAnonymous()).build()));
+    }
+
+    /**
+     * Unit test of {@link Functions#osm_version}.
+     */
+    @Test
+    public void testOsmVersion() {
+        assertEquals(0, Functions.osm_version(new EnvBuilder(NODE).build()));
+    }
+
+    /**
+     * Unit test of {@link Functions#osm_changeset_id}.
+     */
+    @Test
+    public void testOsmChangesetId() {
+        assertEquals(0, Functions.osm_changeset_id(new EnvBuilder(NODE).build()));
+    }
+
+    /**
+     * Unit test of {@link Functions#osm_timestamp}.
+     */
+    @Test
+    public void testOsmTimestamp() {
+        assertEquals(0, Functions.osm_timestamp(new EnvBuilder(NODE).build()));
+    }
+}