feat: [go-feature-flag] Support flag metadata

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

@@ -1,8 +1,5 @@
 package dev.openfeature.contrib.providers.gofeatureflag;
 
-import static java.net.HttpURLConnection.HTTP_BAD_REQUEST;
-import static java.net.HttpURLConnection.HTTP_UNAUTHORIZED;
-
 import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.SerializationFeature;
@@ -12,35 +9,23 @@
 import dev.openfeature.contrib.providers.gofeatureflag.bean.GoFeatureFlagUser;
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidEndpoint;
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidOptions;
-import dev.openfeature.sdk.ErrorCode;
-import dev.openfeature.sdk.EvaluationContext;
-import dev.openfeature.sdk.FeatureProvider;
-import dev.openfeature.sdk.Hook;
-import dev.openfeature.sdk.Metadata;
-import dev.openfeature.sdk.MutableStructure;
-import dev.openfeature.sdk.ProviderEvaluation;
-import dev.openfeature.sdk.Reason;
-import dev.openfeature.sdk.Structure;
-import dev.openfeature.sdk.Value;
+import dev.openfeature.sdk.*;
 import dev.openfeature.sdk.exceptions.FlagNotFoundError;
 import dev.openfeature.sdk.exceptions.GeneralError;
 import dev.openfeature.sdk.exceptions.OpenFeatureError;
 import dev.openfeature.sdk.exceptions.TypeMismatchError;
-import okhttp3.ConnectionPool;
-import okhttp3.HttpUrl;
-import okhttp3.MediaType;
-import okhttp3.OkHttpClient;
-import okhttp3.Request;
-import okhttp3.RequestBody;
-import okhttp3.Response;
-import okhttp3.ResponseBody;
+import okhttp3.*;
+
 import java.io.IOException;
 import java.time.Instant;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
+import static java.net.HttpURLConnection.HTTP_BAD_REQUEST;
+import static java.net.HttpURLConnection.HTTP_UNAUTHORIZED;
+
 /**
  * GoFeatureFlagProvider is the JAVA provider implementation for the feature flag solution GO Feature Flag.
  */
@@ -226,14 +211,15 @@ private <T> ProviderEvaluation<T> resolveEvaluationGoFeatureFlagProxy(
 
                 if (flagValue.getClass() != expectedType) {
                     throw new TypeMismatchError("Flag value " + key + " had unexpected type "
-                                                        + flagValue.getClass() + ", expected " + expectedType + ".");
+                            + flagValue.getClass() + ", expected " + expectedType + ".");
                 }
 
                 return ProviderEvaluation.<T>builder()
                         .errorCode(mapErrorCode(goffResp.getErrorCode()))
                         .reason(goffResp.getReason())
                         .value(flagValue)
                         .variant(goffResp.getVariationType())
+                        .flagMetadata(this.convertFlagMetadata(goffResp.getMetadata()))
                         .build();
 
             }
@@ -256,6 +242,32 @@ private ErrorCode mapErrorCode(String errorCode) {
         }
     }
 
+    /**
+     * convertFlagMetadata is converting the flagMetadata object received from the server
+     * to an ImmutableMetadata format known by Open Feature.
+     *
+     * @param flagMetadata - metadata received from the server
+     * @return a converted metadata object.
+     */
+    private ImmutableMetadata convertFlagMetadata(Map<String, Object> flagMetadata) {
+        ImmutableMetadata.ImmutableMetadataBuilder builder = ImmutableMetadata.builder();
+        flagMetadata.forEach((k, v) -> {
+            if (v instanceof Long) {
+                builder.addLong(k, (Long) v);
+            } else if (v instanceof Integer) {
+                builder.addInteger(k, (Integer) v);
+            } else if (v instanceof Float) {
+                builder.addFloat(k, (Float) v);
+            } else if (v instanceof Double) {
+                builder.addDouble(k, (Double) v);
+            } else if (v instanceof Boolean) {
+                builder.addBoolean(k, (Boolean) v);
+            } else {
+                builder.addString(k, v.toString());
+            }
+        });
+        return builder.build();
+    }
 
     /**
      * convertValue is converting the object return by the proxy response in the right type.

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

@@ -4,6 +4,8 @@
 import lombok.Setter;
 import lombok.ToString;
 
+import java.util.Map;
+
 /**
  * GoFeatureFlagResponse is the response returned by the relay proxy.
  */
@@ -18,6 +20,7 @@ public class GoFeatureFlagResponse {
     private String reason;
     private String errorCode;
     private Object value;
+    private Map<String, Object> metadata;
 }
 
 

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

@@ -7,18 +7,14 @@
 import java.util.Arrays;
 import java.util.List;
 
+import dev.openfeature.sdk.*;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidEndpoint;
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidOptions;
 import dev.openfeature.contrib.providers.gofeatureflag.exception.InvalidTargetingKey;
-import dev.openfeature.sdk.MutableContext;
-import dev.openfeature.sdk.MutableStructure;
-import dev.openfeature.sdk.ProviderEvaluation;
-import dev.openfeature.sdk.Reason;
-import dev.openfeature.sdk.Value;
 import dev.openfeature.sdk.exceptions.FlagNotFoundError;
 import dev.openfeature.sdk.exceptions.GeneralError;
 import dev.openfeature.sdk.exceptions.TypeMismatchError;
@@ -56,6 +52,12 @@ public MockResponse dispatch(RecordedRequest request) {
     private HttpUrl baseUrl;
     private MutableContext evaluationContext;
 
+    private final static ImmutableMetadata defaultMetadata =
+            ImmutableMetadata.builder()
+                    .addString("pr_link", "https://github.com/thomaspoignant/go-feature-flag/pull/916")
+                    .addInteger("version", 1)
+                    .build();
+
     @BeforeEach
     void beforeEach() throws IOException {
         this.server = new MockWebServer();
@@ -153,6 +155,9 @@ void should_resolve_a_valid_boolean_flag_with_TARGETING_MATCH_reason() throws In
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -163,6 +168,9 @@ void should_return_custom_reason_if_returned_by_relay_proxy() throws InvalidOpti
         assertNull(res.getErrorCode());
         assertEquals("CUSTOM_REASON", res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -187,6 +195,9 @@ void should_resolve_a_valid_string_flag_with_TARGETING_MATCH_reason() throws Inv
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -211,6 +222,9 @@ void should_resolve_a_valid_integer_flag_with_TARGETING_MATCH_reason() throws In
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -235,6 +249,9 @@ void should_resolve_a_valid_double_flag_with_TARGETING_MATCH_reason() throws Inv
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -254,6 +271,9 @@ void should_resolve_a_valid_value_flag_with_TARGETING_MATCH_reason() throws Inva
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -265,6 +285,9 @@ void should_wrap_into_value_if_wrong_type() throws InvalidOptions {
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -296,6 +319,9 @@ void should_throw_an_error_if_no_targeting_key() throws InvalidOptions {
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     @Test
@@ -306,6 +332,9 @@ void should_not_fail_if_receive_an_unknown_field_in_response() throws InvalidOpt
         assertNull(res.getErrorCode());
         assertEquals(Reason.TARGETING_MATCH.toString(), res.getReason());
         assertEquals("True", res.getVariant());
+        assertAll("Test flagMetadata",
+                () -> assertEquals(defaultMetadata.getInteger("version"), res.getFlagMetadata().getInteger("version")),
+                () -> assertEquals(defaultMetadata.getString("pr_link"), res.getFlagMetadata().getString("pr_link")));
     }
 
     private String readMockResponse(String filename) throws IOException {

providers/go-feature-flag/src/test/resources/mock_responses/bool_targeting_match.json

@@ -5,5 +5,9 @@
   "version": 0,
   "reason": "TARGETING_MATCH",
   "errorCode": "",
-  "value": true
+  "value": true,
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/disabled.json

@@ -5,5 +5,9 @@
   "version": 0,
   "reason": "DISABLED",
   "errorCode": "",
-  "value": true
+  "value": true,
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/double_key.json

@@ -5,5 +5,9 @@
   "version": 0,
   "reason": "TARGETING_MATCH",
   "errorCode": "",
-  "value": 100.25
+  "value": 100.25,
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/flag_not_found.json

@@ -5,5 +5,9 @@
   "version": 0,
   "reason": "ERROR",
   "errorCode": "FLAG_NOT_FOUND",
-  "value": "false"
+  "value": "false",
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/integer_key.json

@@ -5,5 +5,9 @@
   "version": 0,
   "reason": "TARGETING_MATCH",
   "errorCode": "",
-  "value": 100
+  "value": 100,
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/list_key.json

@@ -11,5 +11,9 @@
     "test2",
     "false",
     "test3"
-  ]
+  ],
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/object_key.json

@@ -11,5 +11,9 @@
     "test3": 123.3,
     "test4": 1,
     "test5": null
+  },
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
   }
 }

providers/go-feature-flag/src/test/resources/mock_responses/string_key.json

@@ -5,5 +5,9 @@
   "version": 0,
   "reason": "TARGETING_MATCH",
   "errorCode": "",
-  "value": "CC0000"
+  "value": "CC0000",
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/unknown_field.json

@@ -7,5 +7,9 @@
   "errorCode": "",
   "value": true,
   "unknown_field": true,
-  "unknown_field2": "unknown_field2"
+  "unknown_field2": "unknown_field2",
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }

providers/go-feature-flag/src/test/resources/mock_responses/unknown_reason.json

@@ -5,5 +5,9 @@
   "version": 0,
   "reason": "CUSTOM_REASON",
   "errorCode": "",
-  "value": true
+  "value": true,
+  "metadata": {
+    "pr_link": "https://github.com/thomaspoignant/go-feature-flag/pull/916",
+    "version": 1
+  }
 }