Fix negative DateInterval

src/Symfony/Component/Serializer/Normalizer/DateIntervalNormalizer.php

@@ -29,7 +29,7 @@ class DateIntervalNormalizer implements NormalizerInterface, DenormalizerInterfa
     /**
      * @param string $format
      */
-    public function __construct($format = 'P%yY%mM%dDT%hH%iM%sS')
+    public function __construct($format = '%rP%yY%mM%dDT%hH%iM%sS')
     {
         $this->format = $format;
     }
@@ -76,12 +76,34 @@ class DateIntervalNormalizer implements NormalizerInterface, DenormalizerInterfa
 
         $dateIntervalFormat = isset($context[self::FORMAT_KEY]) ? $context[self::FORMAT_KEY] : $this->format;
 
-        $valuePattern = '/^'.preg_replace('/%([yYmMdDhHiIsSwW])(\w)/', '(?P<$1>\d+)$2', $dateIntervalFormat).'$/';
+        $signPattern = '';
+        switch (substr($dateIntervalFormat, 0, 2)) {
+            case '%R':
+                $signPattern = '[-+]';
+                $dateIntervalFormat = substr($dateIntervalFormat, 2);
+                break;
+            case '%r':
+                $signPattern = '-?';
+                $dateIntervalFormat = substr($dateIntervalFormat, 2);
+                break;
+        }
+        $valuePattern = '/^'.$signPattern.preg_replace('/%([yYmMdDhHiIsSwW])(\w)/', '(?P<$1>\d+)$2', $dateIntervalFormat).'$/';
         if (!preg_match($valuePattern, $data)) {
             throw new UnexpectedValueException(sprintf('Value "%s" contains intervals not accepted by format "%s".', $data, $dateIntervalFormat));
         }
 
         try {
+            if ('-' === $data[0]) {
+                $interval = new \DateInterval(substr($data, 1));
+                $interval->invert = 1;
+
+                return $interval;
+            }
+
+            if ('+' === $data[0]) {
+                return new \DateInterval(substr($data, 1));
+            }
+
             return new \DateInterval($data);
         } catch (\Exception $e) {
             throw new UnexpectedValueException($e->getMessage(), $e->getCode(), $e);
@@ -98,6 +120,6 @@ class DateIntervalNormalizer implements NormalizerInterface, DenormalizerInterfa
 
     private function isISO8601($string)
     {
-        return preg_match('/^P(?=\w*(?:\d|%\w))(?:\d+Y|%[yY]Y)?(?:\d+M|%[mM]M)?(?:(?:\d+D|%[dD]D)|(?:\d+W|%[wW]W))?(?:T(?:\d+H|[hH]H)?(?:\d+M|[iI]M)?(?:\d+S|[sS]S)?)?$/', $string);
+        return preg_match('/^[\-+]?P(?=\w*(?:\d|%\w))(?:\d+Y|%[yY]Y)?(?:\d+M|%[mM]M)?(?:(?:\d+D|%[dD]D)|(?:\d+W|%[wW]W))?(?:T(?:\d+H|[hH]H)?(?:\d+M|[iI]M)?(?:\d+S|[sS]S)?)?$/', $string);
     }
 }

src/Symfony/Component/Serializer/Tests/Normalizer/DateIntervalNormalizerTest.php

@@ -29,6 +29,11 @@ class DateIntervalNormalizerTest extends TestCase
             ['P%yY%mM%dDT%hH%iM', 'P10Y2M3DT16H5M', 'P10Y2M3DT16H5M'],
             ['P%yY%mM%dDT%hH', 'P10Y2M3DT16H', 'P10Y2M3DT16H'],
             ['P%yY%mM%dD', 'P10Y2M3D', 'P10Y2M3DT0H'],
+            ['%RP%yY%mM%dD', '-P10Y2M3D', '-P10Y2M3DT0H'],
+            ['%RP%yY%mM%dD', '+P10Y2M3D', '+P10Y2M3DT0H'],
+            ['%RP%yY%mM%dD', '+P10Y2M3D', 'P10Y2M3DT0H'],
+            ['%rP%yY%mM%dD', '-P10Y2M3D', '-P10Y2M3DT0H'],
+            ['%rP%yY%mM%dD', 'P10Y2M3D', 'P10Y2M3DT0H'],
         ];
 
         return $data;
@@ -50,7 +55,7 @@ class DateIntervalNormalizerTest extends TestCase
      */
     public function testNormalizeUsingFormatPassedInContext($format, $output, $input)
     {
-        $this->assertEquals($output, $this->normalizer->normalize(new \DateInterval($input), null, [DateIntervalNormalizer::FORMAT_KEY => $format]));
+        $this->assertEquals($output, $this->normalizer->normalize($this->getInterval($input), null, [DateIntervalNormalizer::FORMAT_KEY => $format]));
     }
 
     /**
@@ -58,7 +63,7 @@ class DateIntervalNormalizerTest extends TestCase
      */
     public function testNormalizeUsingFormatPassedInConstructor($format, $output, $input)
     {
-        $this->assertEquals($output, (new DateIntervalNormalizer($format))->normalize(new \DateInterval($input)));
+        $this->assertEquals($output, (new DateIntervalNormalizer($format))->normalize($this->getInterval($input)));
     }
 
     public function testNormalizeInvalidObjectThrowsException()
@@ -84,7 +89,7 @@ class DateIntervalNormalizerTest extends TestCase
      */
     public function testDenormalizeUsingFormatPassedInContext($format, $input, $output)
     {
-        $this->assertDateIntervalEquals(new \DateInterval($output), $this->normalizer->denormalize($input, \DateInterval::class, null, [DateIntervalNormalizer::FORMAT_KEY => $format]));
+        $this->assertDateIntervalEquals($this->getInterval($input), $this->normalizer->denormalize($input, \DateInterval::class, null, [DateIntervalNormalizer::FORMAT_KEY => $format]));
     }
 
     /**
@@ -92,7 +97,7 @@ class DateIntervalNormalizerTest extends TestCase
      */
     public function testDenormalizeUsingFormatPassedInConstructor($format, $input, $output)
     {
-        $this->assertDateIntervalEquals(new \DateInterval($output), (new DateIntervalNormalizer($format))->denormalize($input, \DateInterval::class));
+        $this->assertDateIntervalEquals($this->getInterval($input), (new DateIntervalNormalizer($format))->denormalize($input, \DateInterval::class));
     }
 
     public function testDenormalizeExpectsString()
@@ -124,4 +129,20 @@ class DateIntervalNormalizerTest extends TestCase
     {
         $this->assertEquals($expected->format('%RP%yY%mM%dDT%hH%iM%sS'), $actual->format('%RP%yY%mM%dDT%hH%iM%sS'));
     }
+
+    private function getInterval($data)
+    {
+        if ('-' === $data[0]) {
+            $interval = new \DateInterval(substr($data, 1));
+            $interval->invert = 1;
+
+            return $interval;
+        }
+
+        if ('+' === $data[0]) {
+            return new \DateInterval(substr($data, 1));
+        }
+
+        return new \DateInterval($data);
+    }
 }