Add unit test for Issue 124

#124

src/test/java/biweekly/issues/Issue124.java

@@ -0,0 +1,46 @@
+package biweekly.issues;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.junit.Test;
+
+import biweekly.ICalVersion;
+import biweekly.io.ParseContext;
+import biweekly.io.scribe.property.RecurrenceRuleScribe;
+import biweekly.parameter.ICalParameters;
+import biweekly.property.RecurrenceRule;
+import biweekly.util.Recurrence;
+
+/**
+ * @author Michael Angstadt
+ * @see "https://github.com/mangstadt/biweekly/issues/124"
+ */
+public class Issue124 {
+	@Test
+	public void test() throws Exception {
+		String input = "INVALID";
+		Recurrence recur = parseRecurrence(input);
+
+		Map<String, List<String>> expectedXRules = new HashMap<String, List<String>>();
+		List<String> values = new ArrayList<String>();
+		values.add("");
+		expectedXRules.put(input, values);
+
+		assertNull(recur.getFrequency());
+		assertEquals(expectedXRules, recur.getXRules());
+	}
+
+	private Recurrence parseRecurrence(String input) {
+		RecurrenceRuleScribe scribe = new RecurrenceRuleScribe();
+		ParseContext context = new ParseContext();
+		context.setVersion(ICalVersion.V2_0);
+		RecurrenceRule rrule = scribe.parseText(input, null, new ICalParameters(), context);
+		return rrule.getValue();
+	}
+}