fix: If withProxy(apiKey) is set the client does not set custom heade…

…rs (#191)

Since our README explicitly states that using withProxy($apiKey) is in
lieu of using custom headers for the Authorization header, our SDK
now makes sure to check if the proxyApiKey is set, and if so, uses it
to set the Authorization header also for client registration and client
metrics.

src/UnleashBuilder.php

@@ -529,6 +529,7 @@ public function build(): Unleash
 
         if ($this->proxyKey !== null) {
             $configuration->setProxyKey($this->proxyKey);
+            $configuration->setHeaders(array_merge($this->headers, ['Authorization' => $this->proxyKey]));
             $proxyRepository = new DefaultUnleashProxyRepository(
                 $configuration,
                 $httpClient,

tests/UnleashBuilderTest.php

@@ -883,6 +883,27 @@ public function testBuilderWithProxyKeyYieldsProxyUnleash()
         self::assertInstanceOf(DefaultProxyUnleash::class, $base->build());
     }
 
+    public function testbuilderWithProxyKeyYieldsAuthorizationHeader()
+    {
+        $base = $this->instance->withProxy('proxy-key')->withAppUrl('https://localhost')->withInstanceId('test')->withAppName('test');
+        $unleash = $base->build();
+        $reflection = new ReflectionObject($unleash);
+        $repositoryProperty = $reflection->getProperty('repository');
+        $repositoryProperty->setAccessible(true);
+        $repository = $repositoryProperty->getValue($unleash);
+
+        $reflection = new ReflectionObject($repository);
+        $configurationProperty = $reflection->getProperty('configuration');
+        $configurationProperty->setAccessible(true);
+        $configuration = $configurationProperty->getValue($repository);
+
+        $reflection = new ReflectionObject($configuration);
+        $headersPropertyBuilt = $reflection->getProperty('headers');
+        $headersPropertyBuilt->setAccessible(true);
+        $headersBuilt = $headersPropertyBuilt->getValue($configuration);
+        self::assertArrayHasKey('Authorization', $headersBuilt);
+    }
+
     private function getConfiguration(DefaultUnleash $unleash): UnleashConfiguration
     {
         $configurationProperty = (new ReflectionObject($unleash))->getProperty('configuration');