Index: trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/FunctionsTest.java
===================================================================
--- trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/FunctionsTest.java	(revision 16109)
+++ trunk/test/unit/org/openstreetmap/josm/gui/mappaint/mapcss/FunctionsTest.java	(revision 16110)
@@ -3,4 +3,5 @@
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 import static org.openstreetmap.josm.data.osm.OsmPrimitiveType.NODE;
 
@@ -89,3 +90,17 @@
         assertEquals(0, Functions.osm_timestamp(new EnvBuilder(NODE).build()));
     }
+
+    /**
+     * Unit test of {@code Functions#to_xxx}
+     */
+    @Test
+    public void testParseFunctions() {
+        assertTrue(Functions.to_boolean("true"));
+        assertEquals(1, Functions.to_byte("1"));
+        assertEquals(1, Functions.to_short("1"));
+        assertEquals(1, Functions.to_int("1"));
+        assertEquals(1L, Functions.to_long("1"));
+        assertEquals(1f, Functions.to_float("1"), 1e-10);
+        assertEquals(1d, Functions.to_double("1"), 1e-10);
+    }
 }