feat(go-feature-flag): Add exporterMetadata in the evaluation call (#1193)

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

Author: thomaspoignant

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

@@ -10,6 +10,7 @@
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidTypeInCache;
 import dev.openfeature.contrib.providers.gofeatureflag.hook.DataCollectorHook;
 import dev.openfeature.contrib.providers.gofeatureflag.hook.DataCollectorHookOptions;
+import dev.openfeature.contrib.providers.gofeatureflag.hook.EnrichEvaluationContextHook;
 import dev.openfeature.sdk.EvaluationContext;
 import dev.openfeature.sdk.EventProvider;
 import dev.openfeature.sdk.Hook;
@@ -104,6 +105,7 @@ public void initialize(EvaluationContext evaluationContext) throws Exception {
         super.initialize(evaluationContext);
         this.gofeatureflagController =
                 GoFeatureFlagController.builder().options(options).build();
+        this.hooks.add(new EnrichEvaluationContextHook(options.getExporterMetadata()));
 
         if (options.getEnableCache() == null || options.getEnableCache()) {
             this.cacheCtrl = CacheController.builder().options(options).build();

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

@@ -90,7 +90,9 @@ public class GoFeatureFlagController {
     @Builder
     private GoFeatureFlagController(final GoFeatureFlagProviderOptions options) throws InvalidOptions {
         this.apiKey = options.getApiKey();
-        this.exporterMetadata = options.getExporterMetadata();
+        this.exporterMetadata = options.getExporterMetadata() == null ? new HashMap<>() : options.getExporterMetadata();
+        this.exporterMetadata.put("provider", "java");
+        this.exporterMetadata.put("openfeature", true);
 
         this.parsedEndpoint = HttpUrl.parse(options.getEndpoint());
         if (this.parsedEndpoint == null) {

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

@@ -0,0 +1,57 @@
+package dev.openfeature.contrib.providers.gofeatureflag.hook;
+
+import dev.openfeature.sdk.EvaluationContext;
+import dev.openfeature.sdk.Hook;
+import dev.openfeature.sdk.HookContext;
+import dev.openfeature.sdk.MutableContext;
+import dev.openfeature.sdk.MutableStructure;
+import dev.openfeature.sdk.Value;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * EnrichEvaluationContextHook is an OpenFeature Hook in charge of enriching the evaluation context.
+ */
+public class EnrichEvaluationContextHook implements Hook<String> {
+    private final Map<String, Object> exporterMetadata;
+
+    public EnrichEvaluationContextHook(Map<String, Object> exporterMetadata) {
+        this.exporterMetadata = Optional.ofNullable(exporterMetadata).orElseGet(HashMap::new);
+    }
+
+    @Override
+    public Optional<EvaluationContext> before(HookContext<String> ctx, Map<String, Object> hints) {
+        if (ctx == null) {
+            return Optional.empty();
+        }
+
+        MutableContext mutableContext =
+                new MutableContext(ctx.getCtx().getTargetingKey(), ctx.getCtx().asMap());
+
+        MutableStructure metadata = new MutableStructure();
+        for (Map.Entry<String, Object> entry : exporterMetadata.entrySet()) {
+            switch (entry.getValue().getClass().getSimpleName()) {
+                case "String":
+                    metadata.add(entry.getKey(), (String) entry.getValue());
+                    break;
+                case "Boolean":
+                    metadata.add(entry.getKey(), (Boolean) entry.getValue());
+                    break;
+                case "Integer":
+                    metadata.add(entry.getKey(), (Integer) entry.getValue());
+                    break;
+                case "Double":
+                    metadata.add(entry.getKey(), (Double) entry.getValue());
+                    break;
+                default:
+                    throw new IllegalArgumentException(
+                            "Unsupported type: " + entry.getValue().getClass().getSimpleName());
+            }
+        }
+        Map<String, Value> expMetadata = new HashMap<>();
+        expMetadata.put("exporterMetadata", new Value(metadata));
+        mutableContext.add("gofeatureflag", new MutableStructure(expMetadata));
+        return Optional.of(mutableContext);
+    }
+}

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

@@ -27,8 +27,6 @@ public class 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

@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.github.benmanes.caffeine.cache.Caffeine;
 import com.google.common.net.HttpHeaders;
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidEndpoint;
@@ -21,6 +22,7 @@
 import dev.openfeature.sdk.Value;
 import java.io.IOException;
 import java.net.URL;
+import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Paths;
@@ -48,12 +50,14 @@ class GoFeatureFlagProviderTest {
     private Map exporterMetadata;
     private int flagChangeCallCounter = 0;
     private boolean flagChanged404 = false;
+    private List<RecordedRequest> requests = new ArrayList<>();
 
     // Dispatcher is the configuration of the mock server to test the provider.
     final Dispatcher dispatcher = new Dispatcher() {
         @NotNull @SneakyThrows
         @Override
         public MockResponse dispatch(RecordedRequest request) {
+            requests.add(request);
             assert request.getPath() != null;
             if (request.getPath().contains("fail_500")) {
                 return new MockResponse().setResponseCode(500);
@@ -987,6 +991,42 @@ void should_send_exporter_metadata() {
                 "we should have the exporter metadata in the last event sent to the data collector");
     }
 
+    @SneakyThrows
+    @Test
+    void should_add_exporter_metadata_into_evaluation_call() {
+        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);
+        ObjectMapper objectMapper = new ObjectMapper();
+        String want = objectMapper
+                .readValue(
+                        "{ \"user\" : { \"key\" : \"d45e303a-38c2-11ed-a261-0242ac120002\", "
+                                + "\"anonymous\" : false, \"custom\" : { \"firstname\" : \"john\", \"gofeatureflag\" : { "
+                                + "\"exporterMetadata\" : { \"openfeature\" : true, \"provider\" : \"java\", \"doubleTest\" : 12345.6789, "
+                                + "\"intTest\" : 1234567890, \"version\" : \"1.0.0\" } }, \"rate\" : 3.14, \"targetingKey\" : "
+                                + "\"d45e303a-38c2-11ed-a261-0242ac120002\", \"company_info\" : { \"size\" : 120, \"name\" : \"my_company\" }, "
+                                + "\"email\" : \"[email protected]\", \"age\" : 30, \"lastname\" : \"doe\", \"professional\" : true, "
+                                + "\"labels\" : [ \"pro\", \"beta\" ] } }, \"defaultValue\" : false }",
+                        Object.class)
+                .toString();
+        String got = objectMapper
+                .readValue(this.requests.get(0).getBody().readString(Charset.defaultCharset()), Object.class)
+                .toString();
+        assertEquals(want, got, "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;