Strengthen tests for datetime mapping

[romm]

As stated by @keichinger in #40 (comment), the test-cases below can lead to false-positive, mainly because every case is mapping to the exact same datetime.

Valinor/tests/Integration/Mapping/Type/DateTimeMappingTest.php

Lines 18 to 60 in f12ef39

	public function test_datetime_properties_are_converted_properly(): void
	{
	$dateTimeInterface = new DateTimeImmutable('@1356097062');
	$dateTimeImmutable = new DateTimeImmutable('@1356097062');
	$dateTimeFromTimestamp = 1356097062;
	$dateTimeFromTimestampWithFormat = [
	'datetime' => 1356097062,
	'format' => 'U',
	];
	$dateTimeFromAtomFormat = '2012-12-21T13:37:42+00:00';
	$dateTimeFromArray = [
	'datetime' => '2012-12-21 13:37:42',
	'format' => 'Y-m-d H:i:s',
	];
	$mysqlDate = '2012-12-21 13:37:42';
	$pgsqlDate = '2012-12-21 13:37:42.123456';
	try {
	$result = $this->mapperBuilder->mapper()->map(AllDateTimeValues::class, [
	'dateTimeInterface' => $dateTimeInterface,
	'dateTimeImmutable' => $dateTimeImmutable,
	'dateTimeFromTimestamp' => $dateTimeFromTimestamp,
	'dateTimeFromTimestampWithFormat' => $dateTimeFromTimestampWithFormat,
	'dateTimeFromAtomFormat' => $dateTimeFromAtomFormat,
	'dateTimeFromArray' => $dateTimeFromArray,
	'mysqlDate' => $mysqlDate,
	'pgsqlDate' => $pgsqlDate,
	]);
	} catch (MappingError $error) {
	$this->mappingFail($error);
	}
	self::assertInstanceOf(DateTimeImmutable::class, $result->dateTimeInterface);
	self::assertEquals($dateTimeInterface, $result->dateTimeInterface);
	self::assertEquals($dateTimeImmutable, $result->dateTimeImmutable);
	self::assertEquals(new DateTimeImmutable("@$dateTimeFromTimestamp"), $result->dateTimeFromTimestamp);
	self::assertEquals(new DateTimeImmutable("@{$dateTimeFromTimestampWithFormat['datetime']}"), $result->dateTimeFromTimestampWithFormat);
	self::assertEquals(DateTimeImmutable::createFromFormat(DATE_ATOM, $dateTimeFromAtomFormat), $result->dateTimeFromAtomFormat);
	self::assertEquals(DateTimeImmutable::createFromFormat($dateTimeFromArray['format'], $dateTimeFromArray['datetime']), $result->dateTimeFromArray);
	self::assertEquals(DateTimeImmutable::createFromFormat(DateTimeObjectBuilder::DATE_MYSQL, $mysqlDate), $result->mysqlDate);
	self::assertEquals(DateTimeImmutable::createFromFormat(DateTimeObjectBuilder::DATE_PGSQL, $pgsqlDate), $result->pgsqlDate);
	}

Changing each case to a different datetime everytime would strengthen the tests and ensure the expected behaviour is correct.

[romm]

Fixed in #84, thanks @Lucian-Olariu!