feat: Update to event schema v4 (#192)

Author: keelerm84

src/LaunchDarkly/Impl/Util.php

@@ -126,6 +126,9 @@ public static function eventHeaders(string $sdkKey, $applicationInfo): array
  {
  $headers = Util::defaultHeaders($sdkKey, $applicationInfo);
  $headers['X-LaunchDarkly-Event-Schema'] = EventPublisher::CURRENT_SCHEMA_VERSION;
+ // Only the presence of this header is important. We encode a string
+ // value of 'true' to ensure it isn't dropped along the way.
+ $headers['X-LaunchDarkly-Unsummarized'] = 'true';
 
  return $headers;
  }

src/LaunchDarkly/Subsystems/EventPublisher.php

@@ -18,7 +18,7 @@ interface EventPublisher
  * @var int
  * @ignore
  */
- const CURRENT_SCHEMA_VERSION = 2;
+ const CURRENT_SCHEMA_VERSION = 4;
 
  /**
  * @param string $sdkKey The SDK key for your account

tests/Impl/Integrations/EventPublisherTest.php

@@ -88,6 +88,7 @@ public function testSendsCorrectBodyAndHeaders($publisher)
  $this->assertEquals('sdk-key', $headers['Authorization']);
  $this->assertEquals('PHPClient/' . LDClient::VERSION, $headers['User-Agent']);
  $this->assertEquals(EventPublisher::CURRENT_SCHEMA_VERSION, $headers['X-LaunchDarkly-Event-Schema']);
+ $this->assertArrayHasKey('X-LaunchDarkly-Unsummarized', $headers);
  $this->assertEquals('application-id/my-id application-version/my-version', $headers['X-LaunchDarkly-Tags']);
  }
 }