Merge pull request #158 from One-com/fix/recur-with-negative-offset

Fix: negative BYYEARDAY indexes into the previous year
kewisch · May 27, 2015 · d5d9133 · d5d9133
2 parents 2580b5d + ef4cf4c
commit d5d9133
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Showing 3 changed files with 97 additions and 18 deletions.
diff --git a/build/ical.js b/build/ical.js
@@ -6684,10 +6684,7 @@ ICAL.RecurIterator = (function() {
           this.increment_year(this.rule.interval);
         }
 
-        var next = ICAL.Time.fromDayOfYear(this.days[0], this.last.year);
-
-        this.last.day = next.day;
-        this.last.month = next.month;
+        this._nextByYearDay();
       }
 
       if (this.rule.freq == "MONTHLY" && this.has_by_data("BYDAY")) {
@@ -7247,15 +7244,27 @@ ICAL.RecurIterator = (function() {
         } while (this.days.length == 0);
       }
 
-      var next = ICAL.Time.fromDayOfYear(this.days[this.days_index],
-                                                this.last.year);
-
-      this.last.day = next.day;
-      this.last.month = next.month;
+      this._nextByYearDay();
 
       return 1;
     },
 
+    _nextByYearDay: function _nextByYearDay() {
+        var doy = this.days[this.days_index];
+        var year = this.last.year;
+        if (doy < 1) {
+            // Time.fromDayOfYear(doy, year) indexes relative to the
+            // start of the given year. That is different from the
+            // semantics of BYYEARDAY where negative indexes are an
+            // offset from the end of the given year.
+            doy += 1;
+            year += 1;
+        }
+        var next = ICAL.Time.fromDayOfYear(doy, year);
+        this.last.day = next.day;
+        this.last.month = next.month;
+    },
+
     ruleDayOfWeek: function ruleDayOfWeek(dow) {
       var matches = dow.match(/([+-]?[0-9])?(MO|TU|WE|TH|FR|SA|SU)/);
       if (matches) {

diff --git a/lib/ical/recur_iterator.js b/lib/ical/recur_iterator.js
@@ -240,10 +240,7 @@ ICAL.RecurIterator = (function() {
           this.increment_year(this.rule.interval);
         }
 
-        var next = ICAL.Time.fromDayOfYear(this.days[0], this.last.year);
-
-        this.last.day = next.day;
-        this.last.month = next.month;
+        this._nextByYearDay();
       }
 
       if (this.rule.freq == "MONTHLY" && this.has_by_data("BYDAY")) {
@@ -803,15 +800,27 @@ ICAL.RecurIterator = (function() {
         } while (this.days.length == 0);
       }
 
-      var next = ICAL.Time.fromDayOfYear(this.days[this.days_index],
-                                                this.last.year);
-
-      this.last.day = next.day;
-      this.last.month = next.month;
+      this._nextByYearDay();
 
       return 1;
     },
 
+    _nextByYearDay: function _nextByYearDay() {
+        var doy = this.days[this.days_index];
+        var year = this.last.year;
+        if (doy < 1) {
+            // Time.fromDayOfYear(doy, year) indexes relative to the
+            // start of the given year. That is different from the
+            // semantics of BYYEARDAY where negative indexes are an
+            // offset from the end of the given year.
+            doy += 1;
+            year += 1;
+        }
+        var next = ICAL.Time.fromDayOfYear(doy, year);
+        this.last.day = next.day;
+        this.last.month = next.month;
+    },
+
     ruleDayOfWeek: function ruleDayOfWeek(dow) {
       var matches = dow.match(/([+-]?[0-9])?(MO|TU|WE|TH|FR|SA|SU)/);
       if (matches) {

diff --git a/test/recur_iterator_test.js b/test/recur_iterator_test.js
@@ -879,4 +879,65 @@ suite('recur_iterator', function() {
       '2019-01-07T08:00:00'
     ]
   });
+
+  // Tycho brahe days - yearly, byYearDay with negative offsets
+  testRRULE('FREQ=YEARLY;BYYEARDAY=1,2,4,6,11,12,20,42,48,49,-306,-303,' +
+            '-293,-292,-266,-259,-258,-239,-228,-209,-168,-164,-134,-133,' +
+            '-113,-105,-87,-56,-44,-26,-21,-14', {
+    dtStart: '2015-01-01',
+    dates: [
+      '2015-01-01',
+      '2015-01-02',
+      '2015-01-04',
+      '2015-01-06',
+      '2015-01-11',
+      '2015-01-12',
+      '2015-01-20',
+      '2015-02-11',
+      '2015-02-17',
+      '2015-02-18',
+      '2015-03-01',
+      '2015-03-04',
+      '2015-03-14',
+      '2015-03-15',
+      '2015-04-10',
+      '2015-04-17',
+      '2015-04-18',
+      '2015-05-07',
+      '2015-05-18',
+      '2015-06-06',
+      '2015-07-17',
+      '2015-07-21',
+      '2015-08-20',
+      '2015-08-21',
+      '2015-09-10',
+      '2015-09-18',
+      '2015-10-06',
+      '2015-11-06',
+      '2015-11-18',
+      '2015-12-06',
+      '2015-12-11',
+      '2015-12-18'
+    ]
+  });
+
+  // Leap year - yearly, byYearDay with negative offsets
+  testRRULE('FREQ=YEARLY;BYYEARDAY=-308,-307,-306', {
+    dtStart: '2012-01-01',
+    dates: [
+      '2012-02-28',
+      '2012-02-29',
+      '2012-03-01',
+    ]
+  });
+
+  // Non-leap year - yearly, byYearDay with negative offsets
+  testRRULE('FREQ=YEARLY;BYYEARDAY=-307,-306,-305', {
+    dtStart: '2013-01-01',
+    dates: [
+      '2013-02-28',
+      '2013-03-01',
+      '2013-03-02',
+    ]
+  });
 });