Fixing a bug where the checksum would fail due to losing float precision

Author: weaverryan

src/LiveComponent/src/LiveComponentHydrator.php

@@ -257,7 +257,7 @@ private function calculateChecksum(array $dehydratedPropsData): ?string
         // sort so it is always consistent (frontend could have re-ordered data)
         ksort($dehydratedPropsData);
 
-        return base64_encode(hash_hmac('sha256', var_export($dehydratedPropsData, true), $this->secret, true));
+        return base64_encode(hash_hmac('sha256', json_encode($dehydratedPropsData), $this->secret, true));
     }
 
     private function verifyChecksum(array $identifierPops): void

src/LiveComponent/tests/Integration/LiveComponentHydratorTest.php

@@ -105,6 +105,8 @@ private function executeHydrationTestCase(callable $testFactory, int $minPhpVers
         }
 
         $originalPropsToSend = $testCase->changedOriginalProps ?? $dehydratedProps->getProps();
+        // mimic sending over the wire, which can subtle change php types
+        $originalPropsToSend = json_decode(json_encode($originalPropsToSend), true);
 
         $this->hydrator()->hydrate(
             $componentAfterHydration,
@@ -165,6 +167,25 @@ public function provideDehydrationHydrationTests(): iterable
             ;
         }];
 
+        yield 'float: precision change to the frontend works ok' => [function () {
+            return HydrationTest::create(new class() {
+                #[LiveProp(writable: true)]
+                public float $price;
+            })
+                // when the 123.00 float/double is json encoded, it becomes the
+                // integer 123. If not handled correctly, this can cause a checksum
+                // failure: the checksum is originally calculated with the float
+                // 123.00, but then when the props are sent back to the server,
+                // the float is converted to an integer 123, which causes the checksum
+                // to fail.
+                ->mountWith(['price' => 123.00])
+                ->assertDehydratesTo(['price' => 123.00])
+                ->assertObjectAfterHydration(function (object $object) {
+                    $this->assertSame(123.00, $object->price);
+                })
+            ;
+        }];
+
         yield 'DateTime: (de)hydrates correctly' => [function () {
             $date = new \DateTime('2023-03-05 9:23', new \DateTimeZone('America/New_York'));
 
@@ -1042,7 +1063,7 @@ public function __construct()
 
         $updatedProps = ['holdsDateAndEntity.product' => ['name' => 'new name']];
 
-        $result = $this->hydrator()->hydrate(
+        $this->hydrator()->hydrate(
             $component,
             $dehydratedProps->getProps(),
             $updatedProps,