Add DateTime option to Range function

Signed-off-by: davidarendsen <davidarendsen@hey.com>

tests/FormattersTest.php

@@ -18,4 +18,13 @@ final class FormattersTest extends TestCase {
         $this->assertEquals($expected, Formatters::toFluxArrayString($array));
     }
 
+    public function testDateTimeToString()
+    {
+        $dateTime = new DateTime('2022-08-12 17:31:00');
+
+        $expected = 'time(v: 2022-08-12T17:31:00Z)';
+
+        $this->assertEquals($expected, Formatters::dateTimeToString($dateTime));
+    }
+
 }

tests/Functions/RangeFunctionTest.php

@@ -2,6 +2,7 @@
 declare(strict_types=1);
 
 use Arendsen\FluxQueryBuilder\Exception\FunctionRequiredSettingMissingException;
+use Arendsen\FluxQueryBuilder\Formatters;
 use Arendsen\FluxQueryBuilder\Functions\Range;
 use PHPUnit\Framework\TestCase;
 
@@ -25,6 +26,18 @@ final class RangeFunctionTest extends TestCase {
         $this->assertEquals($query, $expression->__toString());
     }
 
+    public function testRangeInBetween()
+    {
+        $expression = new Range([
+            'start' => new DateTime('2022-08-12 17:31:00'),
+            'stop' => new DateTime('2022-08-12 18:31:00'),
+        ]);
+
+        $expected = '|> range(start: time(v: 2022-08-12T17:31:00Z), stop: time(v: 2022-08-12T18:31:00Z)) ';
+
+        $this->assertEquals($expected, $expression->__toString());
+    }
+
     public function testThrowsExceptionWhenStartIsMissing()
     {
         $this->expectException(FunctionRequiredSettingMissingException::class);

tests/QueryBuilderTest.php

@@ -92,14 +92,14 @@ final class QueryBuilderTest extends TestCase {
         $queryBuilder = new QueryBuilder();
         $queryBuilder->fromBucket('test_bucket')
             ->fromMeasurement('test_measurement')
-		    ->addRangeStart('-3h')
+		    ->addRangeStart(new DateTime('2022-08-12 17:31:00'))
             ->addFilter(KeyValue::setEqualTo('_field', 'username'))
             ->addMap('r with name: r.user')
             ->addGroup(['_field', 'ip'])
             ->addReduce(['count' => 'accumulator.count + 1'], ['count' => 0])
             ->addFilter(KeyValue::setGreaterOrEqualTo('count', 1)->andGreaterOrEqualTo('count2', 2));
 
-        $expectedQuery = 'from(bucket: "test_bucket") |> range(start: -3h) ' . 
+        $expectedQuery = 'from(bucket: "test_bucket") |> range(start: time(v: 2022-08-12T17:31:00Z)) ' . 
             '|> reduce(fn: (r, accumulator) => ({count: accumulator.count + 1}), identity: {count: 0}) ' . 
             '|> filter(fn: (r) => r._measurement == "test_measurement") |> filter(fn: (r) => r._field == "username") ' . 
             '|> filter(fn: (r) => r.count >= 1 and r.count2 >= 2) |> map(fn: (r) => ({ r with name: r.user })) ' .