feat: Identity overrides in local evaluation mode (#143)

* feat: Identity overrides in local evaluation mode
- Support environment-supplied identity overrides
- Remove redundant integration config models
- Parse feature state and multivariate feature state UUIDs correctly

Author: khvn26

flagsmith-engine/environments/integrations/models.ts

@@ -1,6 +1,6 @@
 import { FeatureStateModel } from '../features/models';
+import { IdentityModel } from '../identities/models';
 import { ProjectModel } from '../projects/models';
-import { IntegrationModel } from './integrations/models';
 
 export class EnvironmentAPIKeyModel {
     id: number;
@@ -37,10 +37,7 @@ export class EnvironmentModel {
     apiKey: string;
     project: ProjectModel;
     featureStates: FeatureStateModel[] = [];
-    amplitude_config?: IntegrationModel;
-    segment_config?: IntegrationModel;
-    mixpanel_config?: IntegrationModel;
-    heap_config?: IntegrationModel;
+    identityOverrides: IdentityModel[] = [];
 
     constructor(id: number, apiKey: string, project: ProjectModel) {
         this.id = id;

flagsmith-engine/environments/models.ts

@@ -1,4 +1,5 @@
 import { buildFeatureStateModel } from '../features/util';
+import { buildIdentityModel } from '../identities/util';
 import { buildProjectModel } from '../projects/util';
 import { EnvironmentAPIKeyModel, EnvironmentModel } from './models';
 
@@ -13,6 +14,11 @@ export function buildEnvironmentModel(environmentJSON: any) {
         project
     );
     environmentModel.featureStates = featureStates;
+    if (!!environmentJSON.identity_overrides) {
+        environmentModel.identityOverrides = environmentJSON.identity_overrides.map((identityData: any) =>
+            buildIdentityModel(identityData)
+        );
+    }
     return environmentModel;
 }
 

flagsmith-engine/environments/util.ts

@@ -16,25 +16,26 @@ export function buildFeatureStateModel(featuresStateModelJSON: any): FeatureStat
         featuresStateModelJSON.enabled,
         featuresStateModelJSON.django_id,
         featuresStateModelJSON.feature_state_value,
-        featuresStateModelJSON.uuid
+        featuresStateModelJSON.featurestate_uuid
     );
 
-    featureStateModel.featureSegment = featuresStateModelJSON.feature_segment ? 
-        buildFeatureSegment(featuresStateModelJSON.feature_segment) : 
+    featureStateModel.featureSegment = featuresStateModelJSON.feature_segment ?
+        buildFeatureSegment(featuresStateModelJSON.feature_segment) :
         undefined;
 
     const multivariateFeatureStateValues = featuresStateModelJSON.multivariate_feature_state_values
         ? featuresStateModelJSON.multivariate_feature_state_values.map((fsv: any) => {
-              const featureOption = new MultivariateFeatureOptionModel(
-                  fsv.multivariate_feature_option.value,
-                  fsv.multivariate_feature_option.id
-              );
-              return new MultivariateFeatureStateValueModel(
-                  featureOption,
-                  fsv.percentage_allocation,
-                  fsv.id
-              );
-          })
+            const featureOption = new MultivariateFeatureOptionModel(
+                fsv.multivariate_feature_option.value,
+                fsv.multivariate_feature_option.id
+            );
+            return new MultivariateFeatureStateValueModel(
+                featureOption,
+                fsv.percentage_allocation,
+                fsv.id,
+                fsv.mv_fs_value_uuid
+            );
+        })
         : [];
 
     featureStateModel.multivariateFeatureStateValues = multivariateFeatureStateValues;

flagsmith-engine/features/util.ts

@@ -7,7 +7,6 @@ import { SegmentModel } from './segments/models';
 import { FeatureStateNotFound } from './utils/errors';
 
 export { EnvironmentModel } from './environments/models';
-export { IntegrationModel } from './environments/integrations/models';
 export { FeatureStateModel } from './features/models';
 export { IdentityModel } from './identities/models';
 export { TraitModel } from './identities/traits/models';

flagsmith-engine/index.ts

@@ -17,7 +17,6 @@ export {
 
 export {
   EnvironmentModel,
-  IntegrationModel,
   FeatureStateModel,
   IdentityModel,
   TraitModel,

index.ts

@@ -49,6 +49,8 @@ export class Flagsmith {
     offlineMode: boolean = false;
     offlineHandler?: BaseOfflineHandler = undefined;
 
+    identitiesWithOverridesByIdentifier?: Map<string, IdentityModel>;
+
     private cache?: FlagsmithCache;
     private onEnvironmentChange?: (error: Error | null, result: EnvironmentModel) => void;
     private analyticsProcessor?: AnalyticsProcessor;
@@ -143,13 +145,13 @@ export class Flagsmith {
             if (!this.environmentKey) {
                 throw new Error('ValueError: environmentKey is required.');
             }
-    
+
             const apiUrl = data.apiUrl || DEFAULT_API_URL;
             this.apiUrl = apiUrl.endsWith('/') ? apiUrl : `${apiUrl}/`;
             this.environmentFlagsUrl = `${this.apiUrl}flags/`;
             this.identitiesUrl = `${this.apiUrl}identities/`;
             this.environmentUrl = `${this.apiUrl}environment-document/`;
-    
+
             if (this.enableLocalEvaluation) {
                 if (!this.environmentKey.startsWith('ser.')) {
                     console.error(
@@ -166,11 +168,11 @@ export class Flagsmith {
 
             this.analyticsProcessor = data.enableAnalytics
                 ? new AnalyticsProcessor({
-                      environmentKey: this.environmentKey,
-                      baseApiUrl: this.apiUrl,
-                      requestTimeoutMs: this.requestTimeoutMs,
-                      logger: this.logger
-                  })
+                    environmentKey: this.environmentKey,
+                    baseApiUrl: this.apiUrl,
+                    requestTimeoutMs: this.requestTimeoutMs,
+                    logger: this.logger
+                })
                 : undefined;
         }
     }
@@ -256,7 +258,7 @@ export class Flagsmith {
         if (this.enableLocalEvaluation) {
             return new Promise((resolve, reject) => {
                 return this.environmentPromise!.then(() => {
-                    const identityModel = this.buildIdentityModel(
+                    const identityModel = this.getIdentityModel(
                         identifier,
                         Object.keys(traits || {}).map(key => ({
                             key,
@@ -289,6 +291,11 @@ export class Flagsmith {
             } else {
                 this.environment = await request;
             }
+            if (this.environment.identityOverrides?.length) {
+                this.identitiesWithOverridesByIdentifier = new Map<string, IdentityModel>(
+                    this.environment.identityOverrides.map(identity => [identity.identifier, identity]
+                    ));
+            }
             if (this.onEnvironmentChange) {
                 this.onEnvironmentChange(null, this.environment);
             }
@@ -370,7 +377,7 @@ export class Flagsmith {
         identifier: string,
         traits: { [key: string]: any }
     ): Promise<Flags> {
-        const identityModel = this.buildIdentityModel(
+        const identityModel = this.getIdentityModel(
             identifier,
             Object.keys(traits).map(key => ({
                 key,
@@ -458,8 +465,13 @@ export class Flagsmith {
         }
     }
 
-    private buildIdentityModel(identifier: string, traits: { key: string; value: any }[]) {
+    private getIdentityModel(identifier: string, traits: { key: string; value: any }[]) {
         const traitModels = traits.map(trait => new TraitModel(trait.key, trait.value));
+        let identityWithOverrides = this.identitiesWithOverridesByIdentifier?.get(identifier);
+        if (identityWithOverrides) {
+            identityWithOverrides.updateTraits(traitModels);
+            return identityWithOverrides;
+        }
         return new IdentityModel('0', traitModels, [], this.environment.apiKey, identifier);
     }
 }

package-lock.json

@@ -17,6 +17,7 @@
         "feature_states": [
           {
             "feature_state_value": "segment_override",
+            "featurestate_uuid": "dd77a1ab-08cf-4743-8a3b-19e730444a14",
             "multivariate_feature_state_values": [],
             "django_id": 81027,
             "feature": {
@@ -88,5 +89,30 @@
       "featurestate_uuid": "96fc3503-09d7-48f1-a83b-2dc903d5c08a",
       "enabled": false
     }
+  ],
+  "identity_overrides": [
+    {
+      "identifier": "overridden-id",
+      "identity_uuid": "0f21cde8-63c5-4e50-baca-87897fa6cd01",
+      "created_date": "2019-08-27T14:53:45.698555Z",
+      "updated_at": "2023-07-14 16:12:00.000000",
+      "environment_api_key": "B62qaMZNwfiqT76p38ggrQ",
+      "identity_features": [
+        {
+          "id": 1,
+          "feature": {
+            "id": 1,
+            "name": "some_feature",
+            "type": "STANDARD"
+          },
+          "featurestate_uuid": "1bddb9a5-7e59-42c6-9be9-625fa369749f",
+          "feature_state_value": "some-overridden-value",
+          "enabled": false,
+          "environment": 1,
+          "identity": null,
+          "feature_segment": null
+        }
+      ]
+    }
   ]
-}
+}

sdk/index.ts

@@ -1,10 +1,9 @@
 import Flagsmith from '../../sdk';
 import { EnvironmentDataPollingManager } from '../../sdk/polling_manager';
-import fetch, {RequestInit} from 'node-fetch';
+import fetch, { RequestInit } from 'node-fetch';
 import { environmentJSON, environmentModel, flagsJSON, flagsmith, identitiesJSON } from './utils';
 import { DefaultFlag, Flags } from '../../sdk/models';
-import {delay, retryFetch} from '../../sdk/utils';
-import * as utils from '../../sdk/utils';
+import { delay } from '../../sdk/utils';
 import { EnvironmentModel } from '../../flagsmith-engine/environments/models';
 import https from 'https'
 import { BaseOfflineHandler } from '../../sdk/offline_handlers';
@@ -48,18 +47,15 @@ test('test_update_environment_sets_environment', async () => {
 
     const model = environmentModel(JSON.parse(environmentJSON()));
 
-    wipeFeatureStateUUIDs(flg.environment)
-    wipeFeatureStateUUIDs(model)
-
     expect(flg.environment).toStrictEqual(model);
 });
 
 test('test_set_agent_options', async () => {
     const agent = new https.Agent({})
 
     // @ts-ignore
-    fetch.mockImplementation((url:string, options:RequestInit)=>{
-        if(options.agent!==agent) {
+    fetch.mockImplementation((url: string, options: RequestInit) => {
+        if (options.agent !== agent) {
             throw new Error("Agent has not been set on retry fetch")
         }
         return Promise.resolve(new Response(environmentJSON()))
@@ -276,7 +272,7 @@ test('getIdentitySegments throws error if identifier is empty string', () => {
 })
 
 
-test('offline_mode', async() => {
+test('offline_mode', async () => {
     // Given
     const environment: EnvironmentModel = environmentModel(JSON.parse(environmentJSON('offline-environment.json')));
 
@@ -311,19 +307,19 @@ test('test_flagsmith_uses_offline_handler_if_set_and_no_api_response', async ()
     const environment: EnvironmentModel = environmentModel(JSON.parse(environmentJSON('offline-environment.json')));
     const api_url = 'http://some.flagsmith.com/api/v1/';
     const mock_offline_handler = new BaseOfflineHandler() as jest.Mocked<BaseOfflineHandler>;
-  
+
     jest.spyOn(mock_offline_handler, 'getEnvironment').mockReturnValue(environment);
 
     const flagsmith = new Flagsmith({
-      environmentKey: 'some-key',
-      apiUrl: api_url,
-      offlineHandler: mock_offline_handler,
+        environmentKey: 'some-key',
+        apiUrl: api_url,
+        offlineHandler: mock_offline_handler,
     });
 
     jest.spyOn(flagsmith, 'getEnvironmentFlags');
     jest.spyOn(flagsmith, 'getIdentityFlags');
 
-  
+
     flagsmith.environmentFlagsUrl = 'http://some.flagsmith.com/api/v1/environment-flags';
     flagsmith.identitiesUrl = 'http://some.flagsmith.com/api/v1/identities';
 
@@ -337,64 +333,57 @@ test('test_flagsmith_uses_offline_handler_if_set_and_no_api_response', async ()
     fetch.mockReturnValue(Promise.resolve(errorResponse));
 
     // When
-    const environmentFlags:Flags = await flagsmith.getEnvironmentFlags();
-    const identityFlags:Flags = await flagsmith.getIdentityFlags('identity', {});
+    const environmentFlags: Flags = await flagsmith.getEnvironmentFlags();
+    const identityFlags: Flags = await flagsmith.getIdentityFlags('identity', {});
 
     // Then
     expect(mock_offline_handler.getEnvironment).toHaveBeenCalledTimes(1);
     expect(flagsmith.getEnvironmentFlags).toHaveBeenCalled();
     expect(flagsmith.getIdentityFlags).toHaveBeenCalled();
-    
+
     expect(environmentFlags.isFeatureEnabled('some_feature')).toBe(true);
     expect(environmentFlags.getFeatureValue('some_feature')).toBe('offline-value');
-  
+
     expect(identityFlags.isFeatureEnabled('some_feature')).toBe(true);
     expect(identityFlags.getFeatureValue('some_feature')).toBe('offline-value');
 });
 
 test('cannot use offline mode without offline handler', () => {
     // When and Then
     expect(() => new Flagsmith({ offlineMode: true, offlineHandler: undefined })).toThrowError(
-      'ValueError: offlineHandler must be provided to use offline mode.'
+        'ValueError: offlineHandler must be provided to use offline mode.'
     );
 });
-  
+
 test('cannot use both default handler and offline handler', () => {
     // When and Then
     expect(() => new Flagsmith({
-      offlineHandler: new BaseOfflineHandler(),
-      defaultFlagHandler: (flagName) => new DefaultFlag('foo', true)
+        offlineHandler: new BaseOfflineHandler(),
+        defaultFlagHandler: (flagName) => new DefaultFlag('foo', true)
     })).toThrowError('ValueError: Cannot use both defaultFlagHandler and offlineHandler.');
 });
-  
+
 test('cannot create Flagsmith client in remote evaluation without API key', () => {
     // When and Then
     // @ts-ignore
     expect(() => new Flagsmith()).toThrowError('ValueError: environmentKey is required.');
 });
 
 
-async function wipeFeatureStateUUIDs (environmentModel: EnvironmentModel) {
-    // TODO: this has been pulled out of tests above as a helper function.
-    //  I'm not entirely sure why it's necessary, however, we should look to remove.
-    environmentModel.featureStates.forEach(fs => {
-        // @ts-ignore
-        fs.featurestateUUID = undefined;
-        fs.multivariateFeatureStateValues.forEach(mvfsv => {
-            // @ts-ignore
-            mvfsv.mvFsValueUuid = undefined;
-        })
-    });
-    environmentModel.project.segments.forEach(s => {
-        s.featureStates.forEach(fs => {
-            // @ts-ignore
-            fs.featurestateUUID = undefined;
-        })
-    })
-}
-
 function sleep(ms: number) {
     return new Promise((resolve) => {
         setTimeout(resolve, ms);
     });
 }
+test('test_localEvaluation_true__identity_overrides_evaluated', async () => {
+    // @ts-ignore
+    fetch.mockReturnValue(Promise.resolve(new Response(environmentJSON())));
+
+    const flg = new Flagsmith({
+        environmentKey: 'ser.key',
+        enableLocalEvaluation: true,
+    });
+
+    const flags = await flg.getIdentityFlags("overridden-id");
+    expect(flags.getFeatureValue("some_feature")).toEqual("some-overridden-value");
+});