Merge pull request #25 from google/work
Bump pubspec version.
diff --git a/lib/clock.dart b/lib/clock.dart
index 933dee8..f3327f7 100644
--- a/lib/clock.dart
+++ b/lib/clock.dart
@@ -23,6 +23,35 @@
/// A predefined instance of [Clock] that's based on system clock.
const SYSTEM_CLOCK = const Clock();
+/// Days in a month. This array uses 1-based month numbers, i.e. January is
+/// the 1-st element in the array, not the 0-th.
+const _DAYS_IN_MONTH =
+ const [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
+
+int _daysInMonth(int year, int month) =>
+ (month == DateTime.FEBRUARY && _isLeapYear(year))
+ ? 29 : _DAYS_IN_MONTH[month];
+
+bool _isLeapYear(int year) =>
+ (year % 4 == 0) && ((year % 100 != 0) || (year % 400 == 0));
+
+/// Takes a [date] that may be outside the allowed range of dates for a given
+/// [month] in a given [year] and returns the closest date that is within the
+/// allowed range.
+///
+/// For example:
+///
+/// February 31, 2013 => February 28, 2013
+///
+/// When jumping from month to month or from leap year to common year we may
+/// end up in a month that has fewer days than the month we are jumping from.
+/// In that case it is impossible to preserve the exact date. So we "clamp" the
+/// date value to fit within the month. For example, jumping from March 31 one
+/// month back takes us to February 28 (or 29 during a leap year), as February
+/// doesn't have 31-st date.
+int _clampDate(int date, int year, int month) =>
+ date.clamp(1, _daysInMonth(year, month));
+
/// Provides points in time relative to the current point in time, for example:
/// now, 2 days ago, 4 weeks from now, etc.
///
@@ -133,10 +162,13 @@
/// Return the point in time [months] ago on the same date.
DateTime monthsAgo(int months) {
var time = now();
+ var m = (time.month - months - 1) % 12 + 1;
+ var y = time.year - (months + 12 - time.month) ~/ 12;
+ var d = _clampDate(time.day, y, m);
return new DateTime(
- time.year,
- time.month - months,
- time.day,
+ y,
+ m,
+ d,
time.hour,
time.minute,
time.second,
@@ -145,15 +177,31 @@
}
/// Return the point in time [months] from now on the same date.
- DateTime monthsFromNow(int months) => monthsAgo(-months);
+ DateTime monthsFromNow(int months) {
+ var time = now();
+ var m = (time.month + months - 1) % 12 + 1;
+ var y = time.year + (months + time.month - 1) ~/ 12;
+ var d = _clampDate(time.day, y, m);
+ return new DateTime(
+ y,
+ m,
+ d,
+ time.hour,
+ time.minute,
+ time.second,
+ time.millisecond
+ );
+ }
/// Return the point in time [years] ago on the same date.
DateTime yearsAgo(int years) {
var time = now();
+ var y = time.year - years;
+ var d = _clampDate(time.day, y, time.month);
return new DateTime(
- time.year - years,
+ y,
time.month,
- time.day,
+ d,
time.hour,
time.minute,
time.second,
diff --git a/test/clock_test.dart b/test/clock_test.dart
index a9e3bc6..73cdeb4 100644
--- a/test/clock_test.dart
+++ b/test/clock_test.dart
@@ -1,13 +1,13 @@
// Copyright 2013 Google Inc. All Rights Reserved.
//
-// Licensed under the Apache License, Version 2.0 (the "License");
+// 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,
+// 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.
@@ -17,20 +17,30 @@
import 'package:unittest/unittest.dart';
import 'package:quiver/time.dart';
+Clock from(int y, int m, int d) => new Clock.fixed(new DateTime(y, m, d));
+
+expectDate(DateTime date, int y, [int m = 1, int d = 1]) {
+ expect(date, new DateTime(y, m, d));
+}
+
main() {
group('clock', () {
- var subject = new Clock.fixed(new DateTime(2013));
+ Clock subject;
- test("should return a non-null value from system clock", () {
+ setUp(() {
+ subject = new Clock.fixed(new DateTime(2013));
+ });
+
+ test('should return a non-null value from system clock', () {
expect(new Clock().now(), isNotNull);
expect(SYSTEM_CLOCK.now(), isNotNull);
});
// This test may be flaky on certain systems. I ran it over 10 million
// cycles on my machine without any failures, but that's no guarantee.
- test("should be close enough to system clock", () {
- // I picked 2ms because 1ms was starting to get flaky.
- var epsilon = 2;
+ test('should be close enough to system clock', () {
+ // At 10ms the test doesn't seem to be flaky.
+ var epsilon = 10;
expect(new DateTime.now().difference(
new Clock().now()).inMilliseconds.abs(),
lessThan(epsilon));
@@ -39,7 +49,7 @@
lessThan(epsilon));
});
- test("should return time provided by custom TimeFunction", () {
+ test('should return time provided by custom TimeFunction', () {
var time = new DateTime(2013);
var fixedClock = new Clock(() => time);
expect(fixedClock.now(), new DateTime(2013));
@@ -48,19 +58,19 @@
expect(fixedClock.now(), new DateTime(2014));
});
- test("should return fixed time", () {
+ test('should return fixed time', () {
expect(new Clock.fixed(new DateTime(2013)).now(), new DateTime(2013));
});
- test("should return time Duration ago", () {
+ test('should return time Duration ago', () {
expect(subject.agoBy(new Duration(days: 366)), new DateTime(2012));
});
- test("should return time Duration from now", () {
+ test('should return time Duration from now', () {
expect(subject.fromNowBy(new Duration(days: 365)), new DateTime(2014));
});
- test("should return time parts ago", () {
+ test('should return time parts ago', () {
expect(subject.ago(
days: 1,
hours: 1,
@@ -70,7 +80,7 @@
microseconds: 1000), new DateTime(2012, 12, 30, 22, 58, 58, 998));
});
- test("should return time parts from now", () {
+ test('should return time parts from now', () {
expect(subject.fromNow(
days: 1,
hours: 1,
@@ -80,124 +90,138 @@
microseconds: 1000), new DateTime(2013, 1, 2, 1, 1, 1, 2));
});
- test("should return time micros ago", () {
+ test('should return time micros ago', () {
expect(subject.microsAgo(1000),
new DateTime(2012, 12, 31, 23, 59, 59, 999));
});
- test("should return time micros from now", () {
+ test('should return time micros from now', () {
expect(subject.microsFromNow(1000),
new DateTime(2013, 1, 1, 0, 0, 0, 1));
});
- test("should return time millis ago", () {
+ test('should return time millis ago', () {
expect(subject.millisAgo(1000),
new DateTime(2012, 12, 31, 23, 59, 59, 000));
});
- test("should return time millis from now", () {
+ test('should return time millis from now', () {
expect(subject.millisFromNow(3),
new DateTime(2013, 1, 1, 0, 0, 0, 3));
});
- test("should return time seconds ago", () {
+ test('should return time seconds ago', () {
expect(subject.secondsAgo(10),
new DateTime(2012, 12, 31, 23, 59, 50, 000));
});
- test("should return time seconds from now", () {
+ test('should return time seconds from now', () {
expect(subject.secondsFromNow(3),
new DateTime(2013, 1, 1, 0, 0, 3, 0));
});
- test("should return time minutes ago", () {
+ test('should return time minutes ago', () {
expect(subject.minutesAgo(10),
new DateTime(2012, 12, 31, 23, 50, 0, 000));
});
- test("should return time minutes from now", () {
+ test('should return time minutes from now', () {
expect(subject.minutesFromNow(3),
new DateTime(2013, 1, 1, 0, 3, 0, 0));
});
- test("should return time hours ago", () {
+ test('should return time hours ago', () {
expect(subject.hoursAgo(10),
new DateTime(2012, 12, 31, 14, 0, 0, 000));
});
- test("should return time hours from now", () {
+ test('should return time hours from now', () {
expect(subject.hoursFromNow(3),
new DateTime(2013, 1, 1, 3, 0, 0, 0));
});
- test("should return time days ago", () {
- expect(subject.daysAgo(10),
- new DateTime(2012, 12, 22, 0, 0, 0, 000));
+ test('should return time days ago', () {
+ expectDate(subject.daysAgo(10), 2012, 12, 22);
});
- test("should return time days from now", () {
- expect(subject.daysFromNow(3),
- new DateTime(2013, 1, 4, 0, 0, 0, 0));
+ test('should return time days from now', () {
+ expectDate(subject.daysFromNow(3), 2013, 1, 4);
});
- test("should return time months ago on the same date", () {
- expect(subject.monthsAgo(1),
- new DateTime(2012, 12, 1, 0, 0, 0, 000));
- expect(subject.monthsAgo(2),
- new DateTime(2012, 11, 1, 0, 0, 0, 000));
- expect(subject.monthsAgo(3),
- new DateTime(2012, 10, 1, 0, 0, 0, 000));
- expect(subject.monthsAgo(4),
- new DateTime(2012, 9, 1, 0, 0, 0, 000));
+ test('should return time months ago on the same date', () {
+ expectDate(subject.monthsAgo(1), 2012, 12, 1);
+ expectDate(subject.monthsAgo(2), 2012, 11, 1);
+ expectDate(subject.monthsAgo(3), 2012, 10, 1);
+ expectDate(subject.monthsAgo(4), 2012, 9, 1);
});
- test("should return time months from now on the same date", () {
- expect(subject.monthsFromNow(1),
- new DateTime(2013, 2, 1, 0, 0, 0, 0));
- expect(subject.monthsFromNow(2),
- new DateTime(2013, 3, 1, 0, 0, 0, 0));
- expect(subject.monthsFromNow(3),
- new DateTime(2013, 4, 1, 0, 0, 0, 0));
- expect(subject.monthsFromNow(4),
- new DateTime(2013, 5, 1, 0, 0, 0, 0));
+ test('should return time months from now on the same date', () {
+ expectDate(subject.monthsFromNow(1), 2013, 2, 1);
+ expectDate(subject.monthsFromNow(2), 2013, 3, 1);
+ expectDate(subject.monthsFromNow(3), 2013, 4, 1);
+ expectDate(subject.monthsFromNow(4), 2013, 5, 1);
});
- test("should return time years ago on the same date", () {
- expect(subject.yearsAgo(1),
- new DateTime(2012, 1, 1, 0, 0, 0, 000)); // leap year
- expect(subject.yearsAgo(2),
- new DateTime(2011, 1, 1, 0, 0, 0, 000));
- expect(subject.yearsAgo(3),
- new DateTime(2010, 1, 1, 0, 0, 0, 000));
- expect(subject.yearsAgo(4),
- new DateTime(2009, 1, 1, 0, 0, 0, 000));
- expect(subject.yearsAgo(5),
- new DateTime(2008, 1, 1, 0, 0, 0, 000)); // leap year
- expect(subject.yearsAgo(6),
- new DateTime(2007, 1, 1, 0, 0, 0, 000));
- expect(subject.yearsAgo(30),
- new DateTime(1983, 1, 1, 0, 0, 0, 000));
- expect(subject.yearsAgo(2013),
- new DateTime(0, 1, 1, 0, 0, 0, 000));
+ test('should go from 2013-05-31 to 2012-11-30', () {
+ expectDate(from(2013, 5, 31).monthsAgo(6), 2012, 11, 30);
});
- test("should return time years from now on the same date", () {
- expect(subject.yearsFromNow(1),
- new DateTime(2014, 1, 1, 0, 0, 0, 0));
- expect(subject.yearsFromNow(2),
- new DateTime(2015, 1, 1, 0, 0, 0, 0));
- expect(subject.yearsFromNow(3),
- new DateTime(2016, 1, 1, 0, 0, 0, 0));
- expect(subject.yearsFromNow(4),
- new DateTime(2017, 1, 1, 0, 0, 0, 0));
- expect(subject.yearsFromNow(5),
- new DateTime(2018, 1, 1, 0, 0, 0, 0));
- expect(subject.yearsFromNow(6),
- new DateTime(2019, 1, 1, 0, 0, 0, 0));
- expect(subject.yearsFromNow(30),
- new DateTime(2043, 1, 1, 0, 0, 0, 0));
- expect(subject.yearsFromNow(1000),
- new DateTime(3013, 1, 1, 0, 0, 0, 0));
+ test('should go from 2013-03-31 to 2013-02-28 (common year)', () {
+ expectDate(from(2013, 3, 31).monthsAgo(1), 2013, 2, 28);
+ });
+
+ test('should go from 2013-05-31 to 2013-02-28 (common year)', () {
+ expectDate(from(2013, 5, 31).monthsAgo(3), 2013, 2, 28);
+ });
+
+ test('should go from 2004-03-31 to 2004-02-29 (leap year)', () {
+ expectDate(from(2004, 3, 31).monthsAgo(1), 2004, 2, 29);
+ });
+
+ test('should go from 2013-03-31 to 2013-06-30', () {
+ expectDate(from(2013, 3, 31).monthsFromNow(3), 2013, 6, 30);
+ });
+
+ test('should go from 2003-12-31 to 2004-02-29 (common to leap)', () {
+ expectDate(from(2003, 12, 31).monthsFromNow(2), 2004, 2, 29);
+ });
+
+ test('should go from 2004-02-29 to 2003-02-28 by year', () {
+ expectDate(from(2004, 2, 29).yearsAgo(1), 2003, 2, 28);
+ });
+
+ test('should go from 2004-02-29 to 2003-02-28 by month', () {
+ expectDate(from(2004, 2, 29).monthsAgo(12), 2003, 2, 28);
+ });
+
+ test('should go from 2004-02-29 to 2005-02-28 by year', () {
+ expectDate(from(2004, 2, 29).yearsFromNow(1), 2005, 2, 28);
+ });
+
+ test('should go from 2004-02-29 to 2005-02-28 by month', () {
+ expectDate(from(2004, 2, 29).monthsFromNow(12), 2005, 2, 28);
+ });
+
+ test('should return time years ago on the same date', () {
+ expectDate(subject.yearsAgo(1), 2012, 1, 1); // leap year
+ expectDate(subject.yearsAgo(2), 2011, 1, 1);
+ expectDate(subject.yearsAgo(3), 2010, 1, 1);
+ expectDate(subject.yearsAgo(4), 2009, 1, 1);
+ expectDate(subject.yearsAgo(5), 2008, 1, 1); // leap year
+ expectDate(subject.yearsAgo(6), 2007, 1, 1);
+ expectDate(subject.yearsAgo(30), 1983, 1, 1);
+ expectDate(subject.yearsAgo(2013), 0, 1, 1);
+ });
+
+ test('should return time years from now on the same date', () {
+ expectDate(subject.yearsFromNow(1), 2014, 1, 1);
+ expectDate(subject.yearsFromNow(2), 2015, 1, 1);
+ expectDate(subject.yearsFromNow(3), 2016, 1, 1);
+ expectDate(subject.yearsFromNow(4), 2017, 1, 1);
+ expectDate(subject.yearsFromNow(5), 2018, 1, 1);
+ expectDate(subject.yearsFromNow(6), 2019, 1, 1);
+ expectDate(subject.yearsFromNow(30), 2043, 1, 1);
+ expectDate(subject.yearsFromNow(1000), 3013, 1, 1);
});
});
