feat(go-feature-flag): Support Exporter Metadata

Signed-off-by: Thomas Poignant <thomas.poignant@gofeatureflag.org>

providers/go-feature-flag/src/main/java/dev/openfeature/contrib/providers/gofeatureflag/GoFeatureFlagProviderOptions.java

@@ -4,6 +4,7 @@
 import dev.openfeature.sdk.ProviderEvaluation;
 import lombok.Builder;
 import lombok.Getter;
+import java.util.Map;
 
 /** GoFeatureFlagProviderOptions contains the options to initialise the provider. */
 @Builder
@@ -90,4 +91,13 @@ public class GoFeatureFlagProviderOptions {
      * retrieved in the cache. default: false
      */
     private boolean disableDataCollection;
+
+    /**
+     * (optional) 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 Map<String, Object> exporterMetadata;
 }

providers/go-feature-flag/src/main/java/dev/openfeature/contrib/providers/gofeatureflag/controller/GoFeatureFlagController.java

@@ -31,7 +31,10 @@
 import dev.openfeature.sdk.exceptions.TypeMismatchError;
 import java.io.IOException;
 import java.net.HttpURLConnection;
+import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import lombok.Builder;
 import lombok.extern.slf4j.Slf4j;
@@ -69,6 +72,9 @@ public class GoFeatureFlagController {
 
     private final HttpUrl parsedEndpoint;
 
+    /** exporterMetadata contains the metadata to send to the collector API. */
+    private Map<String, Object> exporterMetadata = new HashMap<>();
+
     /**
      * etag contains the etag of the configuration, if null, it means that the configuration has never
      * been retrieved.
@@ -85,6 +91,7 @@ public class GoFeatureFlagController {
     @Builder
     private GoFeatureFlagController(final GoFeatureFlagProviderOptions options) throws InvalidOptions {
         this.apiKey = options.getApiKey();
+        this.exporterMetadata = options.getExporterMetadata();
 
         this.parsedEndpoint = HttpUrl.parse(options.getEndpoint());
         if (this.parsedEndpoint == null) {
@@ -218,7 +225,7 @@ public <T> EvaluationResponse<T> evaluateFlag(
      */
     public void sendEventToDataCollector(List<Event> eventsList) {
         try {
-            Events events = new Events(eventsList);
+            Events events = new Events(eventsList, this.exporterMetadata);
             HttpUrl url = this.parsedEndpoint
                     .newBuilder()
                     .addEncodedPathSegment("v1")

providers/go-feature-flag/src/main/java/dev/openfeature/contrib/providers/gofeatureflag/hook/events/Events.java

@@ -9,16 +9,15 @@
 /** Events data. */
 @Getter
 public class Events {
-    private static final Map<String, String> meta = new HashMap<>();
-
-    static {
-        meta.put("provider", "java");
-        meta.put("openfeature", "true");
-    }
-
+    private final Map<String, Object> meta = new HashMap<>();
     private final List<Event> events;
 
-    public Events(List<Event> events) {
+    public Events(List<Event> events, Map<String, Object> exporterMetadata) {
         this.events = new ArrayList<>(events);
+        this.meta.put("provider", "java");
+        this.meta.put("openfeature", true);
+        if (exporterMetadata != null) {
+            this.meta.putAll(exporterMetadata);
+        }
     }
 }

providers/go-feature-flag/src/test/java/dev/openfeature/contrib/providers/gofeatureflag/GoFeatureFlagProviderTest.java

@@ -26,6 +26,7 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import lombok.SneakyThrows;
@@ -44,6 +45,7 @@
 @Slf4j
 class GoFeatureFlagProviderTest {
     private int publishEventsRequestsReceived = 0;
+    private Map exporterMetadata;
     private int flagChangeCallCounter = 0;
     private boolean flagChanged404 = false;
 
@@ -67,6 +69,7 @@ public MockResponse dispatch(RecordedRequest request) {
                 String requestBody = request.getBody().readString(StandardCharsets.UTF_8);
                 Map<String, Object> map = requestMapper.readValue(requestBody, Map.class);
                 publishEventsRequestsReceived = ((List) map.get("events")).size();
+                exporterMetadata = ((Map) map.get("meta"));
                 if (requestBody.contains("fail_500") && publishEventsRequestsReceived == 1) {
                     return new MockResponse().setResponseCode(502);
                 }
@@ -944,6 +947,44 @@ void should_stop_calling_flag_change_if_receive_404() {
         assertEquals(1, this.flagChangeCallCounter);
     }
 
+    @SneakyThrows
+    @Test
+    void should_send_exporter_metadata() {
+        Map<String, Object> customExporterMetadata = new HashMap<>();
+        customExporterMetadata.put("version", "1.0.0");
+        customExporterMetadata.put("intTest", 1234567890);
+        customExporterMetadata.put("doubleTest", 12345.67890);
+        GoFeatureFlagProvider g = new GoFeatureFlagProvider(GoFeatureFlagProviderOptions.builder()
+                .endpoint(this.baseUrl.toString())
+                .timeout(1000)
+                .enableCache(true)
+                .flushIntervalMs(150L)
+                .exporterMetadata(customExporterMetadata)
+                .build());
+        String providerName = this.testName;
+        OpenFeatureAPI.getInstance().setProviderAndWait(providerName, g);
+        Client client = OpenFeatureAPI.getInstance().getClient(providerName);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        client.getBooleanDetails("bool_targeting_match", false, this.evaluationContext);
+        Thread.sleep(150);
+
+        Map<String, Object> want = new HashMap<>();
+        want.put("version", "1.0.0");
+        want.put("intTest", 1234567890);
+        want.put("doubleTest", 12345.6789);
+        want.put("openfeature",true);
+        want.put("provider", "java");
+        assertEquals(want, this.exporterMetadata,
+                "we should have the exporter metadata in the last event sent to the data collector");
+    }
+
     private String readMockResponse(String filename) throws Exception {
         URL url = getClass().getClassLoader().getResource("mock_responses/" + filename);
         assert url != null;