1 files changed, 93 insertions, 0 deletions
diff --git a/comm/calendar/test/unit/test_timezone_changes.js b/comm/calendar/test/unit/test_timezone_changes.js
new file mode 100644
index 0000000000..125187ca67
--- /dev/null
+++ b/comm/calendar/test/unit/test_timezone_changes.js
@@ -0,0 +1,93 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const FEBRUARY = 1;
+const OCTOBER = 9;
+const NOVEMBER = 10;
+
+const UTC_MINUS_3 = -3 * 3600;
+const UTC_MINUS_2 = -2 * 3600;
+
+function run_test() {
+  do_calendar_startup(run_next_test);
+}
+
+// This test requires timezone data going back to 2016. It's been kept here as an example.
+/* add_test(function testCaracas() {
+    let time = cal.createDateTime();
+    let zone = cal.timezoneService.getTimezone("America/Caracas");
+
+    for (let month = JANUARY; month <= DECEMBER; month++) {
+        time.resetTo(2015, month, 1, 0, 0, 0, zone);
+        equal(time.timezoneOffset, UTC_MINUS_430, time.toString());
+    }
+
+    for (let month = JANUARY; month <= APRIL; month++) {
+        time.resetTo(2016, month, 1, 0, 0, 0, zone);
+        equal(time.timezoneOffset, UTC_MINUS_430, time.toString());
+    }
+
+    time.resetTo(2016, MAY, 1, 1, 0, 0, zone);
+    equal(time.timezoneOffset, UTC_MINUS_430, time.toString());
+
+    time.resetTo(2016, MAY, 1, 3, 0, 0, zone);
+    equal(time.timezoneOffset, UTC_MINUS_4, time.toString());
+
+    for (let month = JUNE; month <= DECEMBER; month++) {
+        time.resetTo(2016, month, 1, 0, 0, 0, zone);
+        equal(time.timezoneOffset, UTC_MINUS_4, time.toString());
+    }
+
+    for (let month = JANUARY; month <= DECEMBER; month++) {
+        time.resetTo(2017, month, 1, 0, 0, 0, zone);
+        equal(time.timezoneOffset, UTC_MINUS_4, time.toString());
+    }
+
+    run_next_test();
+}); */
+
+// Brazil's rules are complicated. This tests every change in the time range we have data for.
+// Updated for 2019b: Brazil no longer has DST.
+add_test(function testSaoPaulo() {
+  let time = cal.createDateTime();
+  let zone = cal.timezoneService.getTimezone("America/Sao_Paulo");
+
+  time.resetTo(2018, FEBRUARY, 17, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_2, time.toString());
+
+  time.resetTo(2018, FEBRUARY, 18, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2018, NOVEMBER, 3, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2018, NOVEMBER, 4, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_2, time.toString());
+
+  time.resetTo(2019, FEBRUARY, 16, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_2, time.toString());
+
+  time.resetTo(2019, FEBRUARY, 17, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2019, NOVEMBER, 2, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2019, NOVEMBER, 3, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2020, FEBRUARY, 15, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2020, FEBRUARY, 16, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2020, OCTOBER, 31, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  time.resetTo(2020, NOVEMBER, 1, 0, 0, 0, zone);
+  equal(time.timezoneOffset, UTC_MINUS_3, time.toString());
+
+  run_next_test();
+});