feat: create EppoPrecomputedClient

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk-common",
-  "version": "4.3.0",
+  "version": "4.3.1-alpha.0",
   "description": "Eppo SDK for client-side JavaScript applications (base for both web and react native)",
   "main": "dist/index.js",
   "files": [

src/api-endpoints.ts

@@ -1,8 +1,13 @@
-import { BASE_URL as DEFAULT_BASE_URL, UFC_ENDPOINT, BANDIT_ENDPOINT } from './constants';
-import { IQueryParams } from './http-client';
+import {
+  BASE_URL as DEFAULT_BASE_URL,
+  UFC_ENDPOINT,
+  BANDIT_ENDPOINT,
+  PRECOMPUTED_FLAGS_ENDPOINT,
+} from './constants';
+import { IQueryParams, IQueryParamsWithSubject } from './http-client';
 
 interface IApiEndpointsParams {
-  queryParams?: IQueryParams;
+  queryParams?: IQueryParams | IQueryParamsWithSubject;
   baseUrl?: string;
 }
 
@@ -27,4 +32,8 @@ export default class ApiEndpoints {
   banditParametersEndpoint(): URL {
     return this.endpoint(BANDIT_ENDPOINT);
   }
+
+  precomputedFlagsEndpoint(): URL {
+    return this.endpoint(PRECOMPUTED_FLAGS_ENDPOINT);
+  }
 }

src/assignment-logger.ts

@@ -50,9 +50,9 @@ export interface IAssignmentEvent {
   metaData?: Record<string, unknown>;
 
   /**
-   * The flag evaluation details
+   * The flag evaluation details. Null if the flag was precomputed.
    */
-  evaluationDetails: IFlagEvaluationDetails;
+  evaluationDetails: IFlagEvaluationDetails | null;
 }
 
 /**

src/client/eppo-client.ts

@@ -515,7 +515,7 @@
         );
         evaluationDetails.banditAction = action;
       }
     } catch (err: any) {
       logger.error('Error determining bandit action', err);
       if (!this.isGracefulFailureMode) {
         throw err;
@@ -752,7 +752,7 @@
         expectedVariationType,
       );
       return this.parseVariationWithDetails(result, defaultValue, expectedVariationType);
     } catch (error: any) {
       const eppoValue = this.rethrowIfNotGraceful(error, defaultValue);
       if (error instanceof FlagEvaluationError && error.flagEvaluationDetails) {
         return {
@@ -790,7 +790,7 @@
         eppoValue: EppoValue.valueOf(result.variation.value, expectedVariationType),
         flagEvaluationDetails: result.flagEvaluationDetails,
       };
     } catch (error: any) {
       const eppoValue = this.rethrowIfNotGraceful(error, defaultValue);
       return {
         eppoValue,
@@ -839,7 +839,13 @@
         'FLAG_UNRECOGNIZED_OR_DISABLED',
         `Unrecognized or disabled flag: ${flagKey}`,
       );
-      return noneResult(flagKey, subjectKey, subjectAttributes, flagEvaluationDetails);
+      return noneResult(
+        flagKey,
+        subjectKey,
+        subjectAttributes,
+        flagEvaluationDetails,
+        configDetails.configFormat,
+      );
     }
 
     if (!checkTypeMatch(expectedVariationType, flag.variationType)) {
@@ -849,7 +855,13 @@
           'TYPE_MISMATCH',
           errorMessage,
         );
-        return noneResult(flagKey, subjectKey, subjectAttributes, flagEvaluationDetails);
+        return noneResult(
+          flagKey,
+          subjectKey,
+          subjectAttributes,
+          flagEvaluationDetails,
+          configDetails.configFormat,
+        );
       }
       throw new TypeError(errorMessage);
     }
@@ -861,7 +873,13 @@
         'FLAG_UNRECOGNIZED_OR_DISABLED',
         `Unrecognized or disabled flag: ${flagKey}`,
       );
-      return noneResult(flagKey, subjectKey, subjectAttributes, flagEvaluationDetails);
+      return noneResult(
+        flagKey,
+        subjectKey,
+        subjectAttributes,
+        flagEvaluationDetails,
+        configDetails.configFormat,
+      );
     }
 
     const result = this.evaluator.evaluateFlag(
@@ -904,6 +922,7 @@
       configFetchedAt: this.flagConfigurationStore.getConfigFetchedAt() ?? '',
       configPublishedAt: this.flagConfigurationStore.getConfigPublishedAt() ?? '',
       configEnvironment: this.flagConfigurationStore.getEnvironment() ?? { name: '' },
+      configFormat: this.flagConfigurationStore.getFormat() ?? '',
     };
   }
 
@@ -1010,7 +1029,7 @@
     eventsToFlush.forEach((event) => {
       try {
         logFunction(event);
       } catch (error: any) {
         logger.error(`[Eppo SDK] Error flushing event to logger: ${error.message}`);
       }
     });
@@ -1057,7 +1076,7 @@
         allocationKey: allocationKey ?? '__eppo_no_allocation',
         variationKey: variation?.key ?? '__eppo_no_variation',
       });
     } catch (error: any) {
       logger.error(`[Eppo SDK] Error logging assignment event: ${error.message}`);
     }
   }