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andreishaandreisha
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Merge pull request #22 from assoconnect/month_traveler
Time traveler
2 parents 26a4ea3 + 4a72fc9 commit 5071861

3 files changed

Lines changed: 173 additions & 2 deletions

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‎src/AbsoluteDate.php‎

Lines changed: 6 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -56,8 +56,12 @@ public function format(string $format = self::DEFAULT_DATE_FORMAT): string
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/**
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* Modify the internal datetime
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* Supported modify strings :
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*
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* This method only supports year, month, and day modifiers
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* @link https://www.php.net/manual/fr/datetime.formats.php
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*
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* @see TimeTraveler for coherent modifications month-over-month & year-over-year
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*
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* @return AbsoluteDate
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*/
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public function modify(string $modifier): self
@@ -76,7 +80,7 @@ public function modify(string $modifier): self
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'ago',
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'this',
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'of',
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'previous'
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'previous',
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];
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preg_match_all('/([a-z]+)/', $modifier, $matches);
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$invalidPatterns = array_diff($matches[0], $validPatterns);

‎src/TimeTraveler.php‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,71 @@
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<?php
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declare(strict_types=1);
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namespace AssoConnect\PHPDate;
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/**
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* This class addresses corner-case of the modify('+1 month') method
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*/
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class TimeTraveler
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{
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/**
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* Adds at most one month to a given date
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*
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* (new AbsoluteDate(2020-01-31))->modify('+1 month') = 2020-02-31 => 2020-03-02 so more than a month
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* addMonth(new AbsoluteDate(2020-01-31)) = 2020-02-29
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*/
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public function addMonth(AbsoluteDate $from): AbsoluteDate
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{
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$expectedMonth = (intval($from->format('n')) % 12) + 1;
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$next = $from->modify('+1 month');
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while ($expectedMonth !== intval($next->format('n'))) {
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$next = $next->modify('-1 day');
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}
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return $next;
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}
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/**
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* Ensures that months calculation are coherent year over year
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*
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* (new AbsoluteDate(2020-01-31))->modify('+1 year') = 2021-01-31
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* (new AbsoluteDate(2020-01-31))
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* ->modify('+1 month') = 2020-02-31 => 2020-03-02
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* ->modify('+1 month') = 2020-04-02
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* ...
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* ->modify('+1 month') = 2021-02-02 but we would expect 2021-01-31
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*
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* $this->addMonth(
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* $this->addMonth(
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* ...
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* $this->addMonth(new AbsoluteDate(2020-01-31))
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* ...
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* )
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* ) = 2021-01-28 but we would expect 2021-01-31
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*/
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public function addMonthWithReference(AbsoluteDate $reference, AbsoluteDate $from): AbsoluteDate
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{
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$next = $this->addMonth($from);
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$day = min(
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intval($reference->format('j')),
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intval($next->modify('last day of this month')->format('j'))
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);
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$dayString = str_pad(strval($day), 2, '0', STR_PAD_LEFT);
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return new AbsoluteDate($next->format('Y-m') . '-' . $dayString);
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}
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/**
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* Add at most a year to a date
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*
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* (new AbsoluteDate(2020-02-29))->modify('+1 year') = 2021-02-29 => 2020-03-01 so more than a year
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*/
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public function addYear(AbsoluteDate $from): AbsoluteDate
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{
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$expectedMonth = intval($from->format('n'));
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$next = $from->modify('+1 year');
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while ($expectedMonth !== intval($next->format('n'))) {
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$next = $next->modify('-1 day');
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}
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return $next;
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}
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}

‎tests/TimeTravelerTest.php‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,96 @@
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<?php
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declare(strict_types=1);
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namespace AssoConnect\PHPDate\Tests;
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use AssoConnect\PHPDate\AbsoluteDate;
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use AssoConnect\PHPDate\TimeTraveler;
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use PHPUnit\Framework\TestCase;
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class TimeTravelerTest extends TestCase
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{
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private TimeTraveler $timeTraveler;
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public function setUp(): void
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{
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$this->timeTraveler = new TimeTraveler();
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}
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/** @dataProvider provideMonths */
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public function testAddMonth(string $from, string $expected): void
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{
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self::assertSame($expected, $this->timeTraveler->addMonth(new AbsoluteDate($from))->__toString());
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}
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/** @return array{string, string}[] */
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public function provideMonths(): iterable
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{
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yield ['2020-01-01', '2020-02-01'];
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yield ['2020-01-28', '2020-02-28'];
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yield ['2020-01-29', '2020-02-29'];
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yield ['2020-01-30', '2020-02-29'];
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yield ['2020-01-31', '2020-02-29'];
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yield ['2020-02-29', '2020-03-29'];
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}
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/** @dataProvider provideMonthsWithReference */
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public function testAddMonthWithReference(string $reference, string $from, string $expected): void
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{
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self::assertSame($expected, $this->timeTraveler->addMonthWithReference(
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new AbsoluteDate($reference),
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new AbsoluteDate($from)
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)->__toString());
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}
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/** @return array{string, string, string}[] */
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public function provideMonthsWithReference(): iterable
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{
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yield ['2020-01-01', '2020-01-01', '2020-02-01'];
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yield ['2020-01-01', '2020-02-01', '2020-03-01'];
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yield ['2020-01-25', '2020-02-25', '2020-03-25'];
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// Test the result day matches the reference day
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yield ['2020-01-30', '2020-02-29', '2020-03-30'];
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yield ['2020-01-31', '2020-02-29', '2020-03-31'];
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yield ['2020-01-31', '2020-03-31', '2020-04-30'];
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}
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/** @dataProvider provideMonthsWithReferenceOverYear */
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public function testAddMonthWithReferenceWorksYearOverYear(string $reference, string $expected): void
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{
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$reference = new AbsoluteDate($reference);
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for ($i = 0; $i < 12; $i++) {
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$actual = $this->timeTraveler->addMonthWithReference($reference, $actual ?? $reference);
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}
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self::assertTrue(isset($actual));
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self::assertSame($expected, $actual->__toString());
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}
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/** @return array{string, string}[] */
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public function provideMonthsWithReferenceOverYear(): iterable
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{
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yield ['2020-01-01', '2021-01-01'];
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yield ['2020-01-15', '2021-01-15'];
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yield ['2020-01-28', '2021-01-28'];
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yield ['2020-01-29', '2021-01-29'];
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yield ['2020-01-30', '2021-01-30'];
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yield ['2020-01-31', '2021-01-31'];
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}
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/** @dataProvider provideYears */
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public function testAddYear(string $from, string $expected): void
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{
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self::assertSame($expected, $this->timeTraveler->addYear(new AbsoluteDate($from))->__toString());
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}
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/** @return array{string, string}[] */
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public function provideYears(): iterable
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{
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yield ['2020-01-01', '2021-01-01'];
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yield ['2020-01-31', '2021-01-31'];
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yield ['2020-02-29', '2021-02-28'];
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}
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}

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