feat: introduce Resolver as a drop in replacement for Evaluator

providers/flagd/README.md

@@ -41,7 +41,7 @@ Consider the following example to create a `FlagdProvider` with in-process evalu
 ```java
 FlagdProvider flagdProvider = new FlagdProvider(
  FlagdOptions.builder()
- .resolverType(Config.Evaluator.IN_PROCESS)
+ .resolverType(Config.Resolver.IN_PROCESS)
  .build());
 ```
 
@@ -55,7 +55,7 @@ To enable this mode, you should provide a valid flag configuration file with the
 ```java
 FlagdProvider flagdProvider = new FlagdProvider(
  FlagdOptions.builder()
- .resolverType(Config.Evaluator.IN_PROCESS)
+ .resolverType(Config.Resolver.IN_PROCESS)
  .offlineFlagSourcePath("PATH")
  .build());
 ```

providers/flagd/src/main/java/dev/openfeature/contrib/providers/flagd/Config.java

@@ -10,7 +10,7 @@
  */
 @Slf4j
 public final class Config {
- static final Evaluator DEFAULT_RESOLVER_TYPE = Evaluator.RPC;
+ static final Resolver DEFAULT_RESOLVER_TYPE = Resolver.RPC;
  static final String DEFAULT_PORT = "8013";
  static final String DEFAULT_TLS = "false";
  static final String DEFAULT_HOST = "localhost";
@@ -32,6 +32,9 @@ public final class Config {
  static final String SOURCE_SELECTOR_ENV_VAR_NAME = "FLAGD_SOURCE_SELECTOR";
  static final String OFFLINE_SOURCE_PATH = "FLAGD_OFFLINE_FLAG_SOURCE_PATH";
 
+ static final String RESOLVER_RPC = "rpc";
+ static final String RESOLVER_IN_PROCESS = "in-process";
+
  public static final String STATIC_REASON = "STATIC";
  public static final String CACHED_REASON = "CACHED";
 
@@ -60,37 +63,79 @@ static int fallBackToEnvOrDefault(String key, int defaultValue) {
  }
  }
 
- static Evaluator fromValueProvider(Function<String, String> provider) {
+ static Resolver fromValueProvider(Function<String, String> provider) {
  final String resolverVar = provider.apply(RESOLVER_ENV_VAR);
  if (resolverVar == null) {
  return DEFAULT_RESOLVER_TYPE;
  }
 
  switch (resolverVar.toLowerCase()) {
  case "in-process":
- return Evaluator.IN_PROCESS;
+ return Resolver.IN_PROCESS;
  case "rpc":
- return Evaluator.RPC;
+ return Resolver.RPC;
  default:
  log.warn("Unsupported resolver variable: {}", resolverVar);
  return DEFAULT_RESOLVER_TYPE;
  }
  }
 
+ // intermediate interface to unify deprecated Evaluator & new Resolver
+ interface EvaluatorType {
+ String asString();
+ }
+
  /**
  * flagd evaluator type.
+ * Deprecated : Please use {@code Config.Resolver}, which is a drop-in replacement of this.
+ */
+ @Deprecated
+ public enum Evaluator implements EvaluatorType {
+ /**
+ * This is the default resolver type, which connects to flagd instance with flag evaluation gRPC contract.
+ * Evaluations are performed remotely.
+ */
+ RPC {
+ public String asString() {
+ return RESOLVER_RPC;
+ }
+ },
+ /**
+ * This is the in-process resolving type, where flags are fetched with flag sync gRPC contract and stored
+ * locally for in-process evaluation.
+ * Evaluations are preformed in-process.
+ */
+ IN_PROCESS {
+ public String asString() {
+ return RESOLVER_IN_PROCESS;
+ }
+ }
+
+ }
+
+
+ /**
+ * flagd Resolver type.
  */
- public enum Evaluator {
+ public enum Resolver implements EvaluatorType {
  /**
  * This is the default resolver type, which connects to flagd instance with flag evaluation gRPC contract.
  * Evaluations are performed remotely.
  */
- RPC,
+ RPC {
+ public String asString() {
+ return RESOLVER_RPC;
+ }
+ },
  /**
  * This is the in-process resolving type, where flags are fetched with flag sync gRPC contract and stored
  * locally for in-process evaluation.
  * Evaluations are preformed in-process.
  */
- IN_PROCESS
+ IN_PROCESS {
+ public String asString() {
+ return RESOLVER_IN_PROCESS;
+ }
+ }
  }
 }

providers/flagd/src/main/java/dev/openfeature/contrib/providers/flagd/FlagdOptions.java

@@ -40,7 +40,7 @@ public class FlagdOptions {
  * flagd resolving type.
  */
  @Builder.Default
- private Config.Evaluator resolverType = fromValueProvider(System::getenv);
+ private Config.EvaluatorType resolverType = fromValueProvider(System::getenv);
 
  /**
  * flagd connection host.

providers/flagd/src/main/java/dev/openfeature/contrib/providers/flagd/FlagdProvider.java

@@ -50,11 +50,11 @@ public FlagdProvider() {
  * @param options {@link FlagdOptions} with
  */
  public FlagdProvider(final FlagdOptions options) {
- switch (options.getResolverType()) {
- case IN_PROCESS:
+ switch (options.getResolverType().asString()) {
+ case Config.RESOLVER_IN_PROCESS:
  this.flagResolver = new InProcessResolver(options, this::setState);
  break;
- case RPC:
+ case Config.RESOLVER_RPC:
  this.flagResolver =
  new GrpcResolver(options,
  new Cache(options.getCacheType(), options.getMaxCacheSize()),

providers/flagd/src/test/java/dev/openfeature/contrib/providers/flagd/FlagdOptionsTest.java

@@ -33,7 +33,7 @@ public void TestDefaults() {
  assertNull(builder.getSelector());
  assertNull(builder.getOpenTelemetry());
  assertNull(builder.getOfflineFlagSourcePath());
- assertEquals(Config.Evaluator.RPC, builder.getResolverType());
+ assertEquals(Config.Resolver.RPC, builder.getResolverType());
  }
 
  @Test
@@ -51,7 +51,7 @@ public void TestBuilderOptions() {
  .selector("app=weatherApp")
  .offlineFlagSourcePath("some-path")
  .openTelemetry(openTelemetry)
- .resolverType(Config.Evaluator.IN_PROCESS)
+ .resolverType(Config.Resolver.IN_PROCESS)
  .build();
 
  assertEquals("https://hosted-flagd", flagdOptions.getHost());
@@ -64,23 +64,23 @@ public void TestBuilderOptions() {
  assertEquals("app=weatherApp", flagdOptions.getSelector());
  assertEquals("some-path", flagdOptions.getOfflineFlagSourcePath());
  assertEquals(openTelemetry, flagdOptions.getOpenTelemetry());
- assertEquals(Config.Evaluator.IN_PROCESS, flagdOptions.getResolverType());
+ assertEquals(Config.Resolver.IN_PROCESS, flagdOptions.getResolverType());
  }
 
 
  @Test
  public void testValueProviderForEdgeCase_valid() {
  Function<String, String> valueProvider = s -> "in-process";
- assertEquals(Config.Evaluator.IN_PROCESS, Config.fromValueProvider(valueProvider));
+ assertEquals(Config.Resolver.IN_PROCESS, Config.fromValueProvider(valueProvider));
 
  valueProvider = s -> "IN-PROCESS";
- assertEquals(Config.Evaluator.IN_PROCESS, Config.fromValueProvider(valueProvider));
+ assertEquals(Config.Resolver.IN_PROCESS, Config.fromValueProvider(valueProvider));
 
  valueProvider = s -> "rpc";
- assertEquals(Config.Evaluator.RPC, Config.fromValueProvider(valueProvider));
+ assertEquals(Config.Resolver.RPC, Config.fromValueProvider(valueProvider));
 
  valueProvider = s -> "RPC";
- assertEquals(Config.Evaluator.RPC, Config.fromValueProvider(valueProvider));
+ assertEquals(Config.Resolver.RPC, Config.fromValueProvider(valueProvider));
  }
 
  @Test

providers/flagd/src/test/java/dev/openfeature/contrib/providers/flagd/e2e/process/FlagdInProcessSetup.java

@@ -19,7 +19,7 @@ public class FlagdInProcessSetup {
  @BeforeAll()
  public static void setup() throws InterruptedException {
  FlagdInProcessSetup.provider = new FlagdProvider(FlagdOptions.builder()
- .resolverType(Config.Evaluator.IN_PROCESS)
+ .resolverType(Config.Resolver.IN_PROCESS)
  .deadline(3000)
  .port(9090)
  .build());

providers/flagd/src/test/java/dev/openfeature/contrib/providers/flagd/e2e/reconnect/process/FlagdInProcessSetup.java

@@ -17,14 +17,14 @@ public class FlagdInProcessSetup {
  @BeforeAll()
  public static void setup() throws InterruptedException {
  FeatureProvider workingProvider = new FlagdProvider(FlagdOptions.builder()
- .resolverType(Config.Evaluator.IN_PROCESS)
+ .resolverType(Config.Resolver.IN_PROCESS)
  .deadline(3000)
  .port(9091)
  .build());
  StepDefinitions.setUnstableProvider(workingProvider);
 
  FeatureProvider unavailableProvider = new FlagdProvider(FlagdOptions.builder()
- .resolverType(Config.Evaluator.IN_PROCESS)
+ .resolverType(Config.Resolver.IN_PROCESS)
  .deadline(100)
  .port(9092) // this port isn't serving anything, error expected
  .build());

providers/flagd/src/test/java/dev/openfeature/contrib/providers/flagd/e2e/reconnect/rpc/FlagdRpcSetup.java

@@ -18,7 +18,7 @@ public class FlagdRpcSetup {
  @BeforeAll()
  public static void setup() throws InterruptedException {
  FeatureProvider workingProvider = new FlagdProvider(FlagdOptions.builder()
- .resolverType(Config.Evaluator.RPC)
+ .resolverType(Config.Resolver.RPC)
  .port(8014)
  // set a generous deadline, to prevent timeouts in actions
  .deadline(3000)
@@ -27,7 +27,7 @@ public static void setup() throws InterruptedException {
  StepDefinitions.setUnstableProvider(workingProvider);
 
  FeatureProvider unavailableProvider = new FlagdProvider(FlagdOptions.builder()
- .resolverType(Config.Evaluator.RPC)
+ .resolverType(Config.Resolver.RPC)
  .port(8015) // this port isn't serving anything, error expected
  // set a generous deadline, to prevent timeouts in actions
  .deadline(100)

providers/flagd/src/test/java/dev/openfeature/contrib/providers/flagd/e2e/rpc/FlagdRpcSetup.java

@@ -20,7 +20,7 @@ public class FlagdRpcSetup {
  @BeforeAll()
  public static void setup() {
  FlagdRpcSetup.provider = new FlagdProvider(FlagdOptions.builder()
- .resolverType(Config.Evaluator.RPC)
+ .resolverType(Config.Resolver.RPC)
  // set a generous deadline, to prevent timeouts in actions
  .deadline(3000)
  .cacheType(CacheType.DISABLED.getValue())

providers/flagd/src/test/java/dev/openfeature/contrib/providers/flagd/resolver/process/InProcessResolverTest.java

@@ -50,9 +50,9 @@ class InProcessResolverTest {
  public void connectorSetup(){
  // given
  FlagdOptions forGrpcOptions =
- FlagdOptions.builder().resolverType(Config.Evaluator.IN_PROCESS).host("localhost").port(8080).build();
+ FlagdOptions.builder().resolverType(Config.Resolver.IN_PROCESS).host("localhost").port(8080).build();
  FlagdOptions forOfflineOptions =
- FlagdOptions.builder().resolverType(Config.Evaluator.IN_PROCESS).offlineFlagSourcePath("path").build();
+ FlagdOptions.builder().resolverType(Config.Resolver.IN_PROCESS).offlineFlagSourcePath("path").build();
 
  // then
  assertInstanceOf(GrpcStreamConnector.class, InProcessResolver.getConnector(forGrpcOptions));