Normative: Fix date difference for end-of-month edge cases #2759
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Additional details and impacted files@@ Coverage Diff @@
## main #2759 +/- ##
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- Coverage 96.59% 96.57% -0.02%
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Files 23 23
Lines 12218 12242 +24
Branches 2263 2268 +5
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+ Hits 11802 11823 +21
- Misses 356 358 +2
- Partials 60 61 +1 ☔ View full report in Codecov by Sentry. |
pipobscure
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This adjusts the difference algorithm for Gregorian-year dates so that when an intermediate date occurs past the end of a month, it is not shifted to the end of that month. Previously, in some edge cases where taking the difference in months or years would return a number of months and zero days, we now return one month less and 28, 29, or 30 days instead. Example: 1970-01-29 until 1971-02-28, largestUnit years Old result: 1 year, 1 month New result: 1 year, 30 days Note that largestUnit weeks and largestUnit days, the latter of which is the default, are not affected. Closes: #2535
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This adds tests specifically for every kind of case that changes due to the tweak to the date difference algorithm: differences from a longer month to a shorter month, when the months are adjacent, in the same year but not adjacent, and in different years. Also adds tests for a case that does *not* change, but would trip on an incorrectly implemented algorithm: when the intermediate months value falls at the end of February. There was incidental coverage of the change to the date difference algorithm in other tests. Those are adjusted, as well. Normative change: tc39/proposal-temporal#2759 Consensus in February 2024
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This adds tests specifically for every kind of case that changes due to the tweak to the date difference algorithm: differences from a longer month to a shorter month, when the months are adjacent, in the same year but not adjacent, and in different years. Also adds tests for a case that does *not* change, but would trip on an incorrectly implemented algorithm: when the intermediate months value falls at the end of February. There was incidental coverage of the change to the date difference algorithm in other tests. Those are adjusted, as well. Normative change: tc39/proposal-temporal#2759 Consensus in February 2024
ptomato
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This adds tests specifically for every kind of case that changes due to the tweak to the date difference algorithm: differences from a longer month to a shorter month, when the months are adjacent, in the same year but not adjacent, and in different years. Also adds tests for a case that does *not* change, but would trip on an incorrectly implemented algorithm: when the intermediate months value falls at the end of February. There was incidental coverage of the change to the date difference algorithm in other tests. Those are adjusted, as well. Normative change: tc39/proposal-temporal#2759 Consensus in February 2024
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This change gained consensus at TC39 on 2024-02-06. |
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This adjusts the difference algorithm for Gregorian-year dates so that when an intermediate date occurs past the end of a month, it is not shifted to the end of that month.
Previously, in some edge cases where taking the difference in months or years would return a number of months and zero days, we now return one month less and 28, 29, or 30 days instead.
Example: 1970-01-29 until 1971-02-28, largestUnit years
Old result: 1 year, 1 month
New result: 1 year, 30 days
Note that largestUnit weeks and largestUnit days, the latter of which is the default, are not affected.
(Note: Stacked on top of an editorial change which I will eventually make a separate PR for.)Closes: #2535