Skip to content

Commit

Permalink
Merge pull request moment#2133 from ichernev:fix-month-diff
Browse files Browse the repository at this point in the history 
Reimplement month diff logic
  • Loading branch information
@ichernev
ichernev committed Dec 30, 2014
2 parents 75ed8e6 + ae83a69 commit 4c60d3c
Show file tree
Hide file tree
Showing 2 changed files with 71 additions and 42 deletions.
37 changes: 23 additions & 14 deletions moment.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -356,6 +356,26 @@
};
}

function monthDiff(a, b) {
// difference in months
var wholeMonthDiff = ((b.year() - a.year()) * 12) + (b.month() - a.month()),
// b is in (anchor - 1 month, anchor + 1 month)
anchor = a.clone().add(wholeMonthDiff, 'months'),
anchor2, adjust;

if (b - anchor < 0) {
anchor2 = a.clone().add(wholeMonthDiff - 1, 'months');
// linear across the month
adjust = (b - anchor) / (anchor - anchor2);
} else {
anchor2 = a.clone().add(wholeMonthDiff + 1, 'months');
// linear across the month
adjust = (b - anchor) / (anchor2 - anchor);
}

return -(wholeMonthDiff + adjust);
}

while (ordinalizeTokens.length) {
i = ordinalizeTokens.pop();
formatTokenFunctions[i + 'o'] = ordinalizeToken(formatTokenFunctions[i], i);
Expand Down Expand Up @@ -2268,30 +2288,19 @@
diff : function (input, units, asFloat) {
var that = makeAs(input, this),
zoneDiff = (that.utcOffset() - this.utcOffset()) * 6e4,
diff, output, daysAdjust;
anchor, diff, output, daysAdjust;

units = normalizeUnits(units);

if (units === 'year' || units === 'month' || units === 'quarter') {
// average number of days in the months in the given dates
diff = (this.daysInMonth() + that.daysInMonth()) * 432e5; // 24 * 60 * 60 * 1000 / 2
// difference in months
output = ((this.year() - that.year()) * 12) + (this.month() - that.month());
// adjust by taking difference in days, average number of days
// and dst in the given months.
daysAdjust = (this - moment(this).startOf('month')) -
(that - moment(that).startOf('month'));
// same as above but with zones, to negate all dst
daysAdjust += ((this.utcOffset() - moment(this).startOf('month').utcOffset()) -
(that.utcOffset() - moment(that).startOf('month').utcOffset())) * 6e4;
output += daysAdjust / diff;
output = monthDiff(this, that);
if (units === 'quarter') {
output = output / 3;
} else if (units === 'year') {
output = output / 12;
}
} else {
diff = (this - that);
diff = this - that;
output = units === 'second' ? diff / 1e3 : // 1000
units === 'minute' ? diff / 6e4 : // 1000 * 60
units === 'hour' ? diff / 36e5 : // 1000 * 60 * 60
Expand Down
76 changes: 48 additions & 28 deletions test/moment/diff.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -132,33 +132,54 @@ exports.diff = {
return;
}

test.expect(16);

a = dst.moment;
b = a.clone().utc().add(12, 'hours').local();
daysInMonth = (a.daysInMonth() + b.daysInMonth()) / 2;
equal(test, b.diff(a, 'ms', true), 12 * 60 * 60 * 1000, 'ms diff across DST');
equal(test, b.diff(a, 's', true), 12 * 60 * 60, 'second diff across DST');
equal(test, b.diff(a, 'm', true), 12 * 60, 'minute diff across DST');
equal(test, b.diff(a, 'h', true), 12, 'hour diff across DST');
equal(test, b.diff(a, 'd', true), (12 - dst.diff) / 24, 'day diff across DST');
equal(test, b.diff(a, 'w', true), (12 - dst.diff) / 24 / 7, 'week diff across DST');
equal(test, b.diff(a, 'M', true), (12 - dst.diff) / 24 / daysInMonth, 'month diff across DST');
equal(test, b.diff(a, 'y', true), (12 - dst.diff) / 24 / daysInMonth / 12, 'year diff across DST');

test.equal(b.diff(a, 'milliseconds', true), 12 * 60 * 60 * 1000,
'ms diff across DST');
test.equal(b.diff(a, 'seconds', true), 12 * 60 * 60,
'second diff across DST');
test.equal(b.diff(a, 'minutes', true), 12 * 60,
'minute diff across DST');
test.equal(b.diff(a, 'hours', true), 12,
'hour diff across DST');
test.equal(b.diff(a, 'days', true), (12 - dst.diff) / 24,
'day diff across DST');
equal(test, b.diff(a, 'weeks', true), (12 - dst.diff) / 24 / 7,
'week diff across DST');
test.ok(0.95 / (2 * 31) < b.diff(a, 'months', true),
'month diff across DST, lower bound');
test.ok(b.diff(a, 'month', true) < 1.05 / (2 * 28),
'month diff across DST, upper bound');
test.ok(0.95 / (2 * 31 * 12) < b.diff(a, 'years', true),
'year diff across DST, lower bound');
test.ok(b.diff(a, 'year', true) < 1.05 / (2 * 28 * 12),
'year diff across DST, upper bound');

a = dst.moment;
b = a.clone().utc().add(12 + dst.diff, 'hours').local();
daysInMonth = (a.daysInMonth() + b.daysInMonth()) / 2;

equal(test, b.diff(a, 'ms', true), (12 + dst.diff) * 60 * 60 * 1000, 'ms diff across DST');
equal(test, b.diff(a, 's', true), (12 + dst.diff) * 60 * 60, 'second diff across DST');
equal(test, b.diff(a, 'm', true), (12 + dst.diff) * 60, 'minute diff across DST');
equal(test, b.diff(a, 'h', true), (12 + dst.diff), 'hour diff across DST');
equal(test, b.diff(a, 'd', true), 12 / 24, 'day diff across DST');
equal(test, b.diff(a, 'w', true), 12 / 24 / 7, 'week diff across DST');
equal(test, b.diff(a, 'M', true), 12 / 24 / daysInMonth, 'month diff across DST');
equal(test, b.diff(a, 'y', true), 12 / 24 / daysInMonth / 12, 'year diff across DST');
test.equal(b.diff(a, 'milliseconds', true),
(12 + dst.diff) * 60 * 60 * 1000,
'ms diff across DST');
test.equal(b.diff(a, 'seconds', true), (12 + dst.diff) * 60 * 60,
'second diff across DST');
test.equal(b.diff(a, 'minutes', true), (12 + dst.diff) * 60,
'minute diff across DST');
test.equal(b.diff(a, 'hours', true), (12 + dst.diff),
'hour diff across DST');
test.equal(b.diff(a, 'days', true), 12 / 24, 'day diff across DST');
equal(test, b.diff(a, 'weeks', true), 12 / 24 / 7,
'week diff across DST');
test.ok(0.95 / (2 * 31) < b.diff(a, 'months', true),
'month diff across DST, lower bound');
test.ok(b.diff(a, 'month', true) < 1.05 / (2 * 28),
'month diff across DST, upper bound');
test.ok(0.95 / (2 * 31 * 12) < b.diff(a, 'years', true),
'year diff across DST, lower bound');
test.ok(b.diff(a, 'year', true) < 1.05 / (2 * 28 * 12),
'year diff across DST, upper bound');

test.done();
},
Expand Down Expand Up @@ -211,17 +232,16 @@ exports.diff = {
},

'month diffs' : function (test) {
test.expect(8);

// due to floating point math errors, these tests just need to be accurate within 0.00000001
equal(test, moment([2012, 0, 1]).diff([2012, 1, 1], 'months', true), -1, 'Jan 1 to Feb 1 should be 1 month');
test.equal(moment([2012, 0, 1]).diff([2012, 1, 1], 'months', true), -1, 'Jan 1 to Feb 1 should be 1 month');
equal(test, moment([2012, 0, 1]).diff([2012, 0, 1, 12], 'months', true), -0.5 / 31, 'Jan 1 to Jan 1 noon should be 0.5 / 31 months');
equal(test, moment([2012, 0, 15]).diff([2012, 1, 15], 'months', true), -1, 'Jan 15 to Feb 15 should be 1 month');
equal(test, moment([2012, 0, 28]).diff([2012, 1, 28], 'months', true), -1, 'Jan 28 to Feb 28 should be 1 month');
equal(test, moment([2012, 0, 31]).diff([2012, 1, 29], 'months', true), -1 + (2 / 30), 'Jan 31 to Feb 29 should be 1 - (2 / 30) months');
equal(test, moment([2012, 0, 31]).diff([2012, 2, 1], 'months', true), -2 + (30 / 31), 'Jan 31 to Mar 1 should be 2 - (30 / 31) months');
equal(test, moment([2012, 0, 31]).diff([2012, 2, 1, 12], 'months', true), -2 + (29.5 / 31), 'Jan 31 to Mar 1 should be 2 - (29.5 / 31) months');
test.equal(moment([2012, 0, 15]).diff([2012, 1, 15], 'months', true), -1, 'Jan 15 to Feb 15 should be 1 month');
test.equal(moment([2012, 0, 28]).diff([2012, 1, 28], 'months', true), -1, 'Jan 28 to Feb 28 should be 1 month');
test.ok(moment([2012, 0, 31]).diff([2012, 1, 29], 'months', true), -1, 'Jan 31 to Feb 29 should be 1 month');
test.ok(-1 > moment([2012, 0, 31]).diff([2012, 2, 1], 'months', true), 'Jan 31 to Mar 1 should be more than 1 month');
test.ok(-30 / 28 < moment([2012, 0, 31]).diff([2012, 2, 1], 'months', true), 'Jan 31 to Mar 1 should be less than 1 month and 1 day');
equal(test, moment([2012, 0, 1]).diff([2012, 0, 31], 'months', true), -(30 / 31), 'Jan 1 to Jan 31 should be 30 / 31 months');
test.ok(0 < moment('2014-02-01').diff(moment('2014-01-31'), 'months', true), 'jan-31 to feb-1 diff is positive');

test.done();
},
Expand Down Expand Up @@ -253,7 +273,7 @@ exports.diff = {
equal(test, moment([2012, 0, 31]).diff([2013, 6, 31], 'years', true), -1.5, 'Jan 31 2012 to Jul 31 2013 should be 1.5 years');
equal(test, moment([2012, 0, 1]).diff([2013, 0, 1, 12], 'years', true), -1 - (0.5 / 31) / 12, 'Jan 1 2012 to Jan 1 2013 noon should be 1+(0.5 / 31) / 12 years');
equal(test, moment([2012, 0, 1]).diff([2013, 6, 1, 12], 'years', true), -1.5 - (0.5 / 31) / 12, 'Jan 1 2012 to Jul 1 2013 noon should be 1.5+(0.5 / 31) / 12 years');
equal(test, moment([2012, 1, 29]).diff([2013, 1, 28], 'years', true), -1 + (1 / 28.5) / 12, 'Feb 29 2012 to Feb 28 2013 should be 1-(1 / 28.5) / 12 years');
equal(test, moment([2012, 1, 29]).diff([2013, 1, 28], 'years', true), -1, 'Feb 29 2012 to Feb 28 2013 should be 1-(1 / 28.5) / 12 years');

test.done();
}
Expand Down

0 comments on commit 4c60d3c

Please sign in to comment.