feat!: graceful fallback to code default (#1461)

marcozabel · toddbaert · web-flow · commit d314df90df26 · 2026-03-11T14:05:23.000-04:00
Signed-off-by: marcozabel &lt;marco.zabel@dynatrace.com&gt;
Signed-off-by: Todd Baert &lt;todd.baert@dynatrace.com&gt;
Co-authored-by: Todd Baert &lt;todd.baert@dynatrace.com&gt;
diff --git a/.gitmodules b/.gitmodules
@@ -13,7 +13,6 @@
 [submodule "libs/shared/flagd-core/test-harness"]
 	path = libs/shared/flagd-core/test-harness
 	url = https://github.com/open-feature/flagd-testbed
-	branch = v2.10.2
 [submodule "libs/shared/flagd-core/spec"]
 	path = libs/shared/flagd-core/spec
 	url = https://github.com/open-feature/spec
diff --git a/libs/providers/flagd-web/schemas b/libs/providers/flagd-web/schemas
@@ -1 +1 @@
-Subproject commit 2852d7772e6b8674681a6ee6b88db10dbe3f6899
+Subproject commit 9f823b5b36bf219f8ea342de006fdf5013c1bc79
diff --git a/libs/providers/flagd-web/src/e2e/step-definitions/flag.ts b/libs/providers/flagd-web/src/e2e/step-definitions/flag.ts
@@ -35,7 +35,7 @@ export const flagStepDefinitions: StepDefinitions = ({ given, and, when, then })
   });
 
   when(
-    /^a string flag with key "(.*)" is evaluated with default value "(.*)"$/,
+    /^a string flag with key "(.*)" is evaluated with (default|fallback) value "(.*)"$/,
     (key: string, defaultValue: string) => {
       flagKey = key;
       fallback = defaultValue;
@@ -224,7 +224,7 @@ export const flagStepDefinitions: StepDefinitions = ({ given, and, when, then })
   });
 
   when(
-    /^a non-existent string flag with key "(.*)" is evaluated with details and a default value "(.*)"$/,
+    /^a non-existent string flag with key "(.*)" is evaluated with details and a (default|fallback) value "(.*)"$/,
     (key: string, defaultValue: string) => {
       flagKey = key;
       fallback = defaultValue;
@@ -247,7 +247,7 @@ export const flagStepDefinitions: StepDefinitions = ({ given, and, when, then })
   );
 
   when(
-    /^a string flag with key "(.*)" is evaluated as an integer, with details and a default value (\d+)$/,
+    /^a string flag with key "(.*)" is evaluated as an integer, with details and a (default|fallback) value (\d+)$/,
     (key: string, defaultValue: string) => {
       flagKey = key;
       fallback = Number.parseInt(defaultValue);
diff --git a/libs/providers/flagd/schemas b/libs/providers/flagd/schemas
@@ -1 +1 @@
-Subproject commit 2852d7772e6b8674681a6ee6b88db10dbe3f6899
+Subproject commit 9f823b5b36bf219f8ea342de006fdf5013c1bc79
diff --git a/libs/providers/flagd/spec b/libs/providers/flagd/spec
@@ -1 +1 @@
-Subproject commit a3678719bf9f62880375ba835ebe1bb7a77de409
+Subproject commit 1115b785d2cd08d16d63e96bdb6a0ac78a65e6ee
diff --git a/libs/providers/flagd/src/e2e/step-definitions/clientSteps.ts b/libs/providers/flagd/src/e2e/step-definitions/clientSteps.ts
@@ -0,0 +1,11 @@
+import type { StepsDefinitionCallbackOptions } from 'jest-cucumber/dist/src/feature-definition-creation';
+import type { State, Steps } from './state';
+import { ClientProviderStatus } from '@openfeature/core';
+
+export const clientSteps: Steps = (state: State) => {
+  return ({ and }: StepsDefinitionCallbackOptions) => {
+    and('the client is in fatal state', () => {
+      expect(state.client?.providerStatus).toBe(ClientProviderStatus.ERROR);
+    });
+  };
+};
diff --git a/libs/providers/flagd/src/e2e/step-definitions/providerSteps.ts b/libs/providers/flagd/src/e2e/step-definitions/providerSteps.ts
@@ -51,6 +51,7 @@ export const providerSteps: Steps =
           break;
         case 'forbidden':
           flagdOptions['port'] = container.getForbiddenPort();
+          flagdOptions['fatalStatusCodes'] = [...(flagdOptions.fatalStatusCodes || []), 'FORBIDDEN'];
           break;
         case 'ssl': {
           flagdOptions['port'] = container.getPort(state.resolverType);
diff --git a/libs/providers/flagd/src/e2e/tests/in-process.spec.ts b/libs/providers/flagd/src/e2e/tests/in-process.spec.ts
@@ -6,8 +6,9 @@ import type { State } from '../step-definitions/state';
 import { eventSteps } from '../step-definitions/eventSteps';
 import { flagSteps } from '../step-definitions/flagSteps';
 import { contextSteps } from '../step-definitions/contextSteps';
+import { clientSteps } from '../step-definitions/clientSteps';
 
-const steps = [providerSteps, configSteps, eventSteps, flagSteps, contextSteps];
+const steps = [providerSteps, configSteps, eventSteps, flagSteps, contextSteps, clientSteps];
 
 jest.setTimeout(50000);
 jest.retryTimes(3);
@@ -23,7 +24,7 @@ describe('in-process', () => {
     loadFeatures(GHERKIN_FLAGD, {
       // remove filters as we add support for features
       // see: https://github.com/open-feature/js-sdk-contrib/issues/1096 and child issues
-      tagFilter: '@in-process and not @targetURI and not @sync and not @unixsocket',
+      tagFilter: '@in-process and not @targetURI and not @sync and not @unixsocket and not @deprecated',
       scenarioNameTemplate: (vars) => {
         return `${vars.scenarioTitle} (${vars.scenarioTags.join(',')} ${vars.featureTags.join(',')})`;
       },
diff --git a/libs/providers/flagd/src/e2e/tests/rpc.spec.ts b/libs/providers/flagd/src/e2e/tests/rpc.spec.ts
@@ -6,8 +6,9 @@ import { eventSteps } from '../step-definitions/eventSteps';
 import { flagSteps } from '../step-definitions/flagSteps';
 import { contextSteps } from '../step-definitions/contextSteps';
 import { GHERKIN_FLAGD } from '../constants';
+import { clientSteps } from '../step-definitions/clientSteps';
 
-const steps = [providerSteps, configSteps, eventSteps, flagSteps, contextSteps];
+const steps = [providerSteps, configSteps, eventSteps, flagSteps, contextSteps, clientSteps];
 
 jest.setTimeout(50000);
 jest.retryTimes(3);
@@ -24,7 +25,7 @@ describe('rpc', () => {
       tagFilter:
         // remove filters as we add support for features
         // see: https://github.com/open-feature/js-sdk-contrib/issues/1096 and child issues
-        '@rpc and not @targetURI and not @caching and not @unixsocket',
+        '@rpc and not @targetURI and not @caching and not @unixsocket and not @deprecated',
       scenarioNameTemplate: (vars) => {
         return `${vars.scenarioTitle} (${vars.scenarioTags.join(',')} ${vars.featureTags.join(',')})`;
       },
diff --git a/libs/providers/flagd/src/lib/flagd-provider.spec.ts b/libs/providers/flagd/src/lib/flagd-provider.spec.ts
@@ -16,8 +16,8 @@ import type {
   ResolveObjectResponse,
   ResolveStringRequest,
   ResolveStringResponse,
-} from '../proto/ts/flagd/evaluation/v1/evaluation';
-import { ServiceClient } from '../proto/ts/flagd/evaluation/v1/evaluation';
+} from '../proto/ts/flagd/evaluation/v2/evaluation';
+import { ServiceClient } from '../proto/ts/flagd/evaluation/v2/evaluation';
 import { FlagdProvider } from './flagd-provider';
 import type { FlagChangeMessage } from './service/grpc/grpc-service';
 import { GRPCService } from './service/grpc/grpc-service';
diff --git a/libs/providers/flagd/src/lib/service/common/grpc-util.spec.ts b/libs/providers/flagd/src/lib/service/common/grpc-util.spec.ts
@@ -61,7 +61,7 @@ describe('buildClientOptions', () => {
       'grpc.default_authority': 'my-authority',
       'grpc.keepalive_time_ms': 5000,
       'grpc.service_config': buildRetryPolicy(
-        ['flagd.evaluation.v1.Service', 'flagd.sync.v1.FlagSyncService'],
+        ['flagd.evaluation.v1.Service', 'flagd.evaluation.v2.Service', 'flagd.sync.v1.FlagSyncService'],
         100,
         200,
       ),
diff --git a/libs/providers/flagd/src/lib/service/common/grpc-util.ts b/libs/providers/flagd/src/lib/service/common/grpc-util.ts
@@ -58,7 +58,7 @@ const CONFIG_TO_GRPC_OPTIONS: {
 export function buildClientOptions(config: Config): ClientOptions {
   const options: Partial<ClientOptions> = {
     'grpc.service_config': buildRetryPolicy(
-      ['flagd.evaluation.v1.Service', 'flagd.sync.v1.FlagSyncService'],
+      ['flagd.evaluation.v1.Service', 'flagd.evaluation.v2.Service', 'flagd.sync.v1.FlagSyncService'],
       config.retryBackoffMs,
       config.retryBackoffMaxMs,
     ),
diff --git a/libs/providers/flagd/src/lib/service/grpc/grpc-service.ts b/libs/providers/flagd/src/lib/service/grpc/grpc-service.ts
@@ -23,8 +23,8 @@ import type {
   ResolveObjectResponse,
   ResolveStringRequest,
   ResolveStringResponse,
-} from '../../../proto/ts/flagd/evaluation/v1/evaluation';
-import { ServiceClient } from '../../../proto/ts/flagd/evaluation/v1/evaluation';
+} from '../../../proto/ts/flagd/evaluation/v2/evaluation';
+import { ServiceClient } from '../../../proto/ts/flagd/evaluation/v2/evaluation';
 import type { FlagdGrpcConfig } from '../../configuration';
 import {
   DEFAULT_MAX_BACKOFF_MS,
@@ -144,38 +144,38 @@ export class GRPCService implements Service {
 
   async resolveBoolean(
     flagKey: string,
-    _: boolean,
+    defaultValue: boolean,
     context: EvaluationContext,
     logger: Logger,
   ): Promise<ResolutionDetails<boolean>> {
-    return this.resolve(this._client.resolveBoolean, flagKey, context, logger);
+    return this.resolve(this._client.resolveBoolean, flagKey, defaultValue, context, logger);
   }
 
   async resolveString(
     flagKey: string,
-    _: string,
+    defaultValue: string,
     context: EvaluationContext,
     logger: Logger,
   ): Promise<ResolutionDetails<string>> {
-    return this.resolve(this._client.resolveString, flagKey, context, logger);
+    return this.resolve(this._client.resolveString, flagKey, defaultValue, context, logger);
   }
 
   async resolveNumber(
     flagKey: string,
-    _: number,
+    defaultValue: number,
     context: EvaluationContext,
     logger: Logger,
   ): Promise<ResolutionDetails<number>> {
-    return this.resolve(this._client.resolveFloat, flagKey, context, logger);
+    return this.resolve(this._client.resolveFloat, flagKey, defaultValue, context, logger);
   }
 
   async resolveObject<T extends JsonValue>(
     flagKey: string,
-    _: T,
+    defaultValue: T,
     context: EvaluationContext,
     logger: Logger,
   ): Promise<ResolutionDetails<T>> {
-    return this.resolve(this._client.resolveObject, flagKey, context, logger);
+    return this.resolve(this._client.resolveObject, flagKey, defaultValue, context, logger);
   }
 
   private listen(
@@ -284,6 +284,7 @@ export class GRPCService implements Service {
       callback: (error: ServiceError | null, response: AnyResponse) => void,
     ) => ClientUnaryCall,
     flagKey: string,
+    defaultValue: T,
     context: EvaluationContext,
     logger: Logger,
   ): Promise<ResolutionDetails<T>> {
@@ -300,8 +301,15 @@ export class GRPCService implements Service {
       .call(this._client, { flagKey, context }, this._metadata)
       .then((resolved) => resolved, this.onRejected);
 
+    let value = response.value as T;
+    // When no default variant is configured, the server returns an empty/zero proto
+    // value with reason=DEFAULT. In that case, return the caller's code default value.
+    if (response.reason === StandardResolutionReasons.DEFAULT && !response.variant) {
+      value = defaultValue;
+    }
+
     const resolved: ResolutionDetails<T> = {
-      value: response.value as T,
+      value,
       reason: response.reason,
       variant: response.variant,
       flagMetadata: response.metadata,
diff --git a/libs/shared/flagd-core/flagd-schemas b/libs/shared/flagd-core/flagd-schemas
@@ -1 +1 @@
-Subproject commit 08b4c52d3b86d686f11e74322dbfee775db91656
+Subproject commit 9f823b5b36bf219f8ea342de006fdf5013c1bc79
diff --git a/libs/shared/flagd-core/spec b/libs/shared/flagd-core/spec
@@ -1 +1 @@
-Subproject commit bb2dc2ce32cd50d307cb944f0e021734780260b6
+Subproject commit 1115b785d2cd08d16d63e96bdb6a0ac78a65e6ee
diff --git a/libs/shared/flagd-core/src/lib/feature-flag.ts b/libs/shared/flagd-core/src/lib/feature-flag.ts
@@ -32,8 +32,14 @@ type RequiredResolutionDetails<T> = Omit<ResolutionDetails<T>, 'value'> & {
         errorMessage: string;
         value?: never;
       }
+    | {
+        value?: T;
+        variant?: string;
+        reason: 'DEFAULT';
+      }
     | {
         value: T;
+        reason: Exclude<ResolutionReason, 'ERROR' | 'DEFAULT'>;
         variant: string;
         errorCode?: never;
         errorMessage?: never;
@@ -149,9 +155,7 @@ export class FeatureFlag {
       (this.defaultVariant === null || this.defaultVariant === undefined)
     ) {
       return {
-        reason: StandardResolutionReasons.ERROR,
-        errorCode: ErrorCode.FLAG_NOT_FOUND,
-        errorMessage: `Flag '${this._key}' has no default variant defined, will use code default`,
+        reason: StandardResolutionReasons.DEFAULT,
         flagMetadata: this.metadata,
       };
     }
diff --git a/libs/shared/flagd-core/src/lib/flagd-core.ts b/libs/shared/flagd-core/src/lib/flagd-core.ts
@@ -132,6 +132,7 @@ export class FlagdCore implements Storage {
           values.push({
             ...result,
             flagKey: key,
+            value: result.value,
           });
         } else {
           logger.debug(`Flag ${key} omitted because ${result.errorCode}: ${result.errorMessage}`);
diff --git a/libs/shared/flagd-core/test-harness b/libs/shared/flagd-core/test-harness
@@ -1 +1 @@
-Subproject commit ecb3d096c82c52424eeb545cf481f2f1d4794d21
+Subproject commit 3bff4b7eaee0efc8cfe60e0ef6fbd77441b370e6
