Tolerate all-day UNTIL with datetime start in lax mode, closes #109 (#117)

Author: dmfs

src/main/java/org/dmfs/rfc5545/recur/RecurrenceRule.java

@@ -50,7 +50,7 @@ public enum RfcMode
          * Parses recurrence rules according to <a href="http://tools.ietf.org/html/rfc2445#section-4.3.10">RFC 2445</a>. Every error will cause an exception to
          * be thrown.
          */
-        RFC2445_STRICT,
+        RFC2445_STRICT(false),
 
         /**
          * Parses recurrence rules according to <a href="http://tools.ietf.org/html/rfc2445#section-4.3.10">RFC 2445</a> in a more tolerant way. The parser will
@@ -59,13 +59,13 @@ public enum RfcMode
          * differently than with {@link #RFC5545_LAX}. {@link #RFC5545_LAX} will just drop all invalid parts and evaluate the rule according to RFC 5545. This
          * mode will evaluate all rules. <p> Also this mode will output rules that comply with RFC 2445. </p>
          */
-        RFC2445_LAX,
+        RFC2445_LAX(true),
 
         /**
          * Parses recurrence rules according to <a href="http://tools.ietf.org/html/rfc5545#section-3.3.10">RFC 5545</a>. Every error will cause an exception to
          * be thrown.
          */
-        RFC5545_STRICT,
+        RFC5545_STRICT(false),
 
         /**
          * Parses recurrence rules according to <a href="http://tools.ietf.org/html/rfc5545#section-3.3.10">RFC 5545</a> in a more tolerant way. The parser will
@@ -74,7 +74,15 @@ public enum RfcMode
          * are evaluated differently than with {@link #RFC2445_LAX}. This mode will just drop all invalid parts and evaluate the rule according to RFC 5545.
          * {@link #RFC2445_LAX} will evaluate all rules. <p> Also this mode will output rules that comply with RFC 5545. </p>
          */
-        RFC5545_LAX;
+        RFC5545_LAX(true);
+
+        final boolean mIsLax;
+
+
+        RfcMode(boolean isLax)
+        {
+            mIsLax = isLax;
+        }
     }
 
 
@@ -847,7 +855,9 @@ boolean expands(RecurrenceRule rule)
                 @Override
                 RuleIterator getExpander(RecurrenceRule rule, RuleIterator previous, CalendarMetrics calendarMetrics, long start, TimeZone startTimeZone)
                 {
-                    return new UntilLimiter(rule, previous, calendarMetrics, startTimeZone);
+                    return rule.mode.mIsLax && rule.getUntil() != null && rule.getUntil().isAllDay()
+                        ? new UntilDateLimiter(rule, previous)
+                        : new UntilLimiter(rule, previous, startTimeZone);
                 }
 
 
@@ -1151,6 +1161,11 @@ public String toString()
      */
     private final static CalendarMetrics DEFAULT_CALENDAR_SCALE = new GregorianCalendarMetrics(Weekday.MO, 4);
 
+    /**
+     * {@link Part}s that don't provide expander or limiter.
+     */
+    private final static Set<Part> NON_EXPANDABLE = EnumSet.of(Part.FREQ, Part.INTERVAL, Part.WKST, Part.RSCALE);
+
     /**
      * The default skip value if RSCALE is present but SKIP is not.
      */
@@ -2140,10 +2155,10 @@ public RecurrenceRuleIterator iterator(DateTime start)
         DateTime until = getUntil();
         if (until != null)
         {
-            if (until.isAllDay() != start.isAllDay())
+            if (!mode.mIsLax && until.isAllDay() != start.isAllDay())
             {
                 throw new IllegalArgumentException(
-                    "using allday start times with non-allday until values (and vice versa) is not allowed");
+                    "using allday start times with non-allday until values (and vice versa) is not allowed in strict modes");
             }
             if (until.isFloating() != start.isFloating())
             {
@@ -2182,21 +2197,20 @@ public RecurrenceRuleIterator iterator(DateTime start)
             }
         }
 
+        parts.removeAll(NON_EXPANDABLE);
+
         for (Part p : parts)
         {
             // add a filter for each rule part
-            if (p != Part.FREQ && p != Part.INTERVAL && p != Part.WKST && p != Part.RSCALE)
+            if (p.expands(this))
             {
-                if (p.expands(this))
-                {
-                    // if a part returns null for the expander just skip it
-                    RuleIterator newIterator = p.getExpander(this, iterator, rScaleCalendarMetrics, startInstance, startTimeZone);
-                    iterator = newIterator == null ? iterator : newIterator;
-                }
-                else
-                {
-                    ((ByExpander) iterator).addFilter(p.getFilter(this, rScaleCalendarMetrics));
-                }
+                // if a part returns null for the expander just skip it
+                RuleIterator newIterator = p.getExpander(this, iterator, rScaleCalendarMetrics, startInstance, startTimeZone);
+                iterator = newIterator == null ? iterator : newIterator;
+            }
+            else
+            {
+                ((ByExpander) iterator).addFilter(p.getFilter(this, rScaleCalendarMetrics));
             }
         }
         return new RecurrenceRuleIterator(iterator, start, rScaleCalendarMetrics);

src/main/java/org/dmfs/rfc5545/recur/UntilDateLimiter.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2013 Marten Gajda <marten@dmfs.org>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.dmfs.rfc5545.recur;
+
+import org.dmfs.rfc5545.DateTime;
+import org.dmfs.rfc5545.Instance;
+
+
+/**
+ * A {@link Limiter} that filters all instances after a certain all-day date (the one specified in the UNTIL part).
+ */
+final class UntilDateLimiter extends Limiter
+{
+    /**
+     * The latest allowed instance start date.
+     */
+    private final long mUntil;
+
+
+    /**
+     * Create a new limiter for an all-day UNTIL part.
+     */
+    public UntilDateLimiter(RecurrenceRule rule, RuleIterator previous)
+    {
+        super(previous);
+        DateTime until = rule.getUntil();
+        if (!until.isAllDay())
+        {
+            throw new RuntimeException("Illegal use of UntilDateLimiter with non-allday date " + until);
+        }
+        mUntil = until.getInstance();
+    }
+
+
+    @Override
+    boolean stop(long instance)
+    {
+        return mUntil < Instance.setSecond(Instance.setMinute(Instance.setHour(Instance.maskWeekday(instance), 0), 0), 0);
+    }
+}

src/main/java/org/dmfs/rfc5545/recur/UntilLimiter.java

@@ -12,14 +12,13 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- * 
+ *
  */
 
 package org.dmfs.rfc5545.recur;
 
 import org.dmfs.rfc5545.DateTime;
 import org.dmfs.rfc5545.Instance;
-import org.dmfs.rfc5545.calendarmetrics.CalendarMetrics;
 
 import java.util.TimeZone;
 
@@ -41,11 +40,11 @@ final class UntilLimiter extends Limiter
      * Create a new limiter for the UNTIL part.
      *
      * @param rule
-     *         The {@link RecurrenceRule} to filter.
+     *     The {@link RecurrenceRule} to filter.
      * @param previous
-     *         The previous filter instance.
+     *     The previous filter instance.
      */
-    public UntilLimiter(RecurrenceRule rule, RuleIterator previous, CalendarMetrics calendarMetrics, TimeZone startTimezone)
+    public UntilLimiter(RecurrenceRule rule, RuleIterator previous, TimeZone startTimezone)
     {
         super(previous);
         DateTime until = rule.getUntil();

src/test/java/org/dmfs/rfc5545/recur/RecurrenceRuleTest.java

@@ -21,17 +21,20 @@
 import org.dmfs.rfc5545.Weekday;
 import org.junit.jupiter.api.Test;
 
+import static org.dmfs.jems2.hamcrest.matchers.LambdaMatcher.having;
+import static org.dmfs.jems2.hamcrest.matchers.fragile.BrokenFragileMatcher.throwing;
 import static org.dmfs.jems2.hamcrest.matchers.single.SingleMatcher.hasValue;
 import static org.dmfs.rfc5545.Weekday.*;
+import static org.dmfs.rfc5545.hamcrest.GeneratorMatcher.generates;
 import static org.dmfs.rfc5545.hamcrest.RecurrenceRuleMatcher.*;
 import static org.dmfs.rfc5545.hamcrest.datetime.BeforeMatcher.before;
 import static org.dmfs.rfc5545.hamcrest.datetime.DayOfMonthMatcher.onDayOfMonth;
 import static org.dmfs.rfc5545.hamcrest.datetime.MonthMatcher.inMonth;
 import static org.dmfs.rfc5545.hamcrest.datetime.WeekDayMatcher.onWeekDay;
 import static org.dmfs.rfc5545.hamcrest.datetime.YearMatcher.inYear;
+import static org.dmfs.rfc5545.recur.RecurrenceRule.RfcMode.*;
 import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.hasToString;
-import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.*;
 
 
 /**
@@ -94,4 +97,64 @@ public void test() throws InvalidRecurrenceRuleException
         System.out.println(rule.getByPart(RecurrenceRule.Part.BYMONTH));
         System.out.println(rule.toString());
     }
+
+
+    /**
+     * see https://github.com/dmfs/lib-recur/issues/109
+     */
+    @Test
+    void testAllDayUntilAndDateTimeStart() throws InvalidRecurrenceRuleException
+    {
+        assertThat(new RecurrenceRule("FREQ=DAILY;BYHOUR=12;UNTIL=20230305", RFC5545_LAX),
+            allOf(validRule(DateTime.parse("20230301T000000"),
+                    walking(),
+                    results(5)),
+                generates("20230301T000000",
+                    "20230301T120000",
+                    "20230302T120000",
+                    "20230303T120000",
+                    "20230304T120000",
+                    "20230305T120000")));
+
+        assertThat(new RecurrenceRule("FREQ=DAILY;BYHOUR=12;UNTIL=20230305", RFC2445_LAX),
+            allOf(validRule(DateTime.parse("20230301T000000"),
+                    walking(),
+                    results(5)),
+                generates("20230301T000000",
+                    "20230301T120000",
+                    "20230302T120000",
+                    "20230303T120000",
+                    "20230304T120000",
+                    "20230305T120000")));
+
+        assertThat(new RecurrenceRule("FREQ=DAILY;UNTIL=20230305", RFC5545_LAX),
+            allOf(validRule(DateTime.parse("20230301T000000"),
+                    walking(),
+                    results(5)),
+                generates("20230301T000000",
+                    "20230301T000000",
+                    "20230302T000000",
+                    "20230303T000000",
+                    "20230304T000000",
+                    "20230305T000000")));
+
+        assertThat(new RecurrenceRule("FREQ=DAILY;UNTIL=20230305", RFC2445_LAX),
+            allOf(validRule(DateTime.parse("20230301T000000"),
+                    walking(),
+                    results(5)),
+                generates("20230301T000000",
+                    "20230301T000000",
+                    "20230302T000000",
+                    "20230303T000000",
+                    "20230304T000000",
+                    "20230305T000000")));
+
+        assertThat(new RecurrenceRule("FREQ=DAILY;BYHOUR=12;UNTIL=20230305", RFC5545_STRICT),
+            is(having(
+                r -> () -> r.iterator(DateTime.parse("20230301T000000")), is(throwing(IllegalArgumentException.class)))));
+
+        assertThat(new RecurrenceRule("FREQ=DAILY;BYHOUR=12;UNTIL=20230305", RFC2445_STRICT),
+            is(having(
+                r -> () -> r.iterator(DateTime.parse("20230301T000000")), is(throwing(IllegalArgumentException.class)))));
+    }
 }