feat(go-feature-flag): Support exporter metadata (#120)

* chore(deps): update dependency datadog/dd-trace to ^0.99.0 (#56)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Signed-off-by: Thomas Poignant <[email protected]>

* feat(go-feature-flag): Support exporter metadata

Signed-off-by: Thomas Poignant <[email protected]>

* upgrade rollout/rox to 6.0.1 (#119)

Signed-off-by: CristianCurteanu <[email protected]>
Signed-off-by: Thomas Poignant <[email protected]>

* fix php doc

Signed-off-by: Thomas Poignant <[email protected]>

* chore: remove hardcoded version (#122)

Signed-off-by: Michael Beemer <[email protected]>
Signed-off-by: Thomas Poignant <[email protected]>

* fix: add explicit usage of json_decode

Signed-off-by: Thomas Poignant <[email protected]>

* fix: use in alphabetical order

Signed-off-by: Thomas Poignant <[email protected]>

* fix lint type in doc

Signed-off-by: Thomas Poignant <[email protected]>

---------

Signed-off-by: Thomas Poignant <[email protected]>
Signed-off-by: CristianCurteanu <[email protected]>
Signed-off-by: Michael Beemer <[email protected]>
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: CristianCurteanu <[email protected]>
Co-authored-by: Michael Beemer <[email protected]>

Author: 4 people

Diff for: providers/GoFeatureFlag/src/config/Config.php

@@ -19,17 +19,38 @@ class Config
      */
     private ?ClientInterface $httpclient;
 
+    /**
+     * @var array<string, mixed> exporterMetadata - is the metadata we send to the GO Feature Flag relay proxy when we report
+     * the evaluation data usage.
+     *
+     * ‼️Important: If you are using a GO Feature Flag relay proxy before version v1.41.0, the information of this
+     * field will not be added to your feature events.
+     */
+    private array $exporterMetadata = [];
+
     /**
      * @param string $endpoint - The endpoint to your GO Feature Flag Instance
      * @param string|null $apiKey - API Key to use to connect to GO Feature Flag
      * @param array<string, string>|null $customHeaders - Custom headers you want to send
+     * @param array<string, mixed>|null $exporterMetadata - Metadata to send to the relay proxy during evaluation data collection
      * @param ClientInterface|null $httpclient - The HTTP Client to use (if you want to use a custom one)
      */
-    public function __construct(string $endpoint, ?string $apiKey = '', ?array $customHeaders = [], ?ClientInterface $httpclient = null)
-    {
+    public function __construct(
+        string $endpoint,
+        ?string $apiKey = '',
+        ?array $customHeaders = [],
+        ?array $exporterMetadata = [],
+        ?ClientInterface $httpclient = null,
+    ) {
         $this->httpclient = $httpclient;
         $this->endpoint = $endpoint;
         $this->customHeaders = $customHeaders ?? [];
+
+        // set default exporter metadata fields
+        $this->exporterMetadata = $exporterMetadata ?? [];
+        $this->exporterMetadata['openfeature'] = true;
+        $this->exporterMetadata['provider'] = 'php';
+
         if ($apiKey !== null && $apiKey !== '') {
             $this->customHeaders['Authorization'] = 'Bearer ' . $apiKey;
         }
@@ -57,4 +78,12 @@ public function getHttpClient(): ?ClientInterface
     {
         return $this->httpclient;
     }
+
+    /**
+     * @return array<string, mixed>
+     */
+    public function getExporterMetadata(): array
+    {
+        return $this->exporterMetadata;
+    }
 }

Diff for: providers/GoFeatureFlag/src/controller/OfrepApi.php

@@ -75,6 +75,9 @@ public function evaluate(string $flagKey, EvaluationContext $evaluationContext):
                 ['targetingKey' => $evaluationContext->getTargetingKey()],
             );
 
+            // Add exporter metadata to the context
+            $fields['gofeatureflag'] = ['exporterMetadata' => $this->options->getExporterMetadata()];
+
             $requestBody = json_encode(['context' => $fields]);
             if ($requestBody === false) {
                 throw new ParseException('failed to encode request body');

Diff for: providers/GoFeatureFlag/tests/unit/GoFeatureFlagProviderTest.php

@@ -21,6 +21,7 @@
 use ReflectionException;
 
 use function PHPUnit\Framework\assertEquals;
+use function json_decode;
 use function json_encode;
 
 class GoFeatureFlagProviderTest extends TestCase
@@ -474,6 +475,52 @@ public function testReturnAnErrorAPIResponseIf500(): void
         assertEquals('boolean_flag', $got->getFlagKey());
     }
 
+    public function testShouldSendExporterMetadataInContext(): void
+    {
+        $mockClient = $this->createMock(ClientInterface::class);
+        $mockResponse = new Response(200, [], json_encode([
+            'key' => 'integer_key',
+            'value' => 42,
+            'reason' => 'TARGETING_MATCH',
+            'variant' => 'default',
+        ]));
+
+        $requestBody = '';
+        $mockClient
+            ->expects($this->once())
+            ->method('sendRequest')
+            ->willReturnCallback(function ($request) use ($mockResponse, &$requestBody) {
+                $requestBody = $request->getBody()->getContents();
+
+                return $mockResponse;
+            });
+
+        $config = new Config(
+            'http://gofeatureflag.org',
+            null,
+            [],
+            ['key1' => 'value', 'key2' => 123, 'key3' => 123.45],
+        );
+
+        $provider = new GoFeatureFlagProvider($config);
+        $this->mockHttpClient($provider, $mockClient);
+
+        $api = OpenFeatureAPI::getInstance();
+        $api->setProvider($provider);
+        $client = $api->getClient();
+        $client->getBooleanDetails('boolean_flag', false, $this->defaultEvaluationContext);
+
+        // get the request body of the request received by the mock client
+        $want = ['key1' => 'value',
+            'key2' => 123,
+            'key3' => 123.45,
+            'openfeature' => true,
+            'provider' => 'php',
+        ];
+        $got = json_decode($requestBody, true)['context']['gofeatureflag']['exporterMetadata'];
+        assertEquals($want, $got);
+    }
+
     protected function setUp(): void
     {
         parent::setUp();