Ability to set configuration request parameters on an already instantiated client instance (#37)

* ability to set configuration request parameters on an already instantiated client

* feedback from PR

Author: aarsilv

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@eppo/js-client-sdk-common",
-  "version": "2.1.0",
+  "version": "2.1.1",
   "description": "Eppo SDK for client-side JavaScript applications (base for both web and react native)",
   "main": "dist/index.js",
   "files": [

src/client/eppo-client.spec.ts

@@ -1160,7 +1160,7 @@ describe('Eppo Client constructed with configuration request parameters', () =>
     mock.teardown();
   });
 
-  it('Fetches initial configuration', async () => {
+  it('Fetches initial configuration with parameters in constructor', async () => {
     client = new EppoClient(storage, requestConfiguration);
     client.setIsGracefulFailureMode(false);
     // no configuration loaded
@@ -1172,6 +1172,19 @@ describe('Eppo Client constructed with configuration request parameters', () =>
     expect(variation).toBe('green');
   });
 
+  it('Fetches initial configuration with parameters provided later', async () => {
+    client = new EppoClient(storage);
+    client.setIsGracefulFailureMode(false);
+    client.setConfigurationRequestParameters(requestConfiguration);
+    // no configuration loaded
+    let variation = client.getAssignment(subjectForGreenVariation, flagKey);
+    expect(variation).toBeNull();
+    // have client fetch configurations
+    await client.fetchFlagConfigurations();
+    variation = client.getAssignment(subjectForGreenVariation, flagKey);
+    expect(variation).toBe('green');
+  });
+
   it.each([
     { pollAfterSuccessfulInitialization: false },
     { pollAfterSuccessfulInitialization: true },

src/client/eppo-client.ts

@@ -115,6 +115,10 @@ export interface IEppoClient {
 
   useCustomAssignmentCache(cache: AssignmentCache<Cacheable>): void;
 
+  setConfigurationRequestParameters(
+    configurationRequestParameters: ExperimentConfigurationRequestParameters,
+  ): void;
+
   fetchFlagConfigurations(): void;
 
   stopPolling(): void;
@@ -141,21 +145,27 @@ export default class EppoClient implements IEppoClient {
   private isGracefulFailureMode = true;
   private assignmentCache: AssignmentCache<Cacheable> | undefined;
   private configurationStore: IConfigurationStore;
-  private configurationRequestConfig: ExperimentConfigurationRequestParameters | undefined;
+  private configurationRequestParameters: ExperimentConfigurationRequestParameters | undefined;
   private requestPoller: IPoller | undefined;
 
   constructor(
     configurationStore: IConfigurationStore,
-    configurationRequestConfig?: ExperimentConfigurationRequestParameters,
+    configurationRequestParameters?: ExperimentConfigurationRequestParameters,
   ) {
     this.configurationStore = configurationStore;
-    this.configurationRequestConfig = configurationRequestConfig;
+    this.configurationRequestParameters = configurationRequestParameters;
+  }
+
+  public setConfigurationRequestParameters(
+    configurationRequestParameters: ExperimentConfigurationRequestParameters,
+  ) {
+    this.configurationRequestParameters = configurationRequestParameters;
   }
 
   public async fetchFlagConfigurations() {
-    if (!this.configurationRequestConfig) {
+    if (!this.configurationRequestParameters) {
       throw new Error(
-        'Eppo SDK unable to fetch flag configurations without a request configuration',
+        'Eppo SDK unable to fetch flag configurations without configuration request parameters',
       );
     }
 
@@ -165,13 +175,13 @@ export default class EppoClient implements IEppoClient {
     }
 
     const axiosInstance = axios.create({
-      baseURL: this.configurationRequestConfig.baseUrl || DEFAULT_BASE_URL,
-      timeout: this.configurationRequestConfig.requestTimeoutMs || DEFAULT_REQUEST_TIMEOUT_MS,
+      baseURL: this.configurationRequestParameters.baseUrl || DEFAULT_BASE_URL,
+      timeout: this.configurationRequestParameters.requestTimeoutMs || DEFAULT_REQUEST_TIMEOUT_MS,
     });
     const httpClient = new HttpClient(axiosInstance, {
-      apiKey: this.configurationRequestConfig.apiKey,
-      sdkName: this.configurationRequestConfig.sdkName,
-      sdkVersion: this.configurationRequestConfig.sdkVersion,
+      apiKey: this.configurationRequestParameters.apiKey,
+      sdkName: this.configurationRequestParameters.sdkName,
+      sdkVersion: this.configurationRequestParameters.sdkVersion,
     });
     const configurationRequestor = new ExperimentConfigurationRequestor(
       this.configurationStore,
@@ -183,16 +193,17 @@ export default class EppoClient implements IEppoClient {
       configurationRequestor.fetchAndStoreConfigurations.bind(configurationRequestor),
       {
         maxStartRetries:
-          this.configurationRequestConfig.numInitialRequestRetries ??
+          this.configurationRequestParameters.numInitialRequestRetries ??
           DEFAULT_INITIAL_CONFIG_REQUEST_RETRIES,
         maxPollRetries:
-          this.configurationRequestConfig.numPollRequestRetries ??
+          this.configurationRequestParameters.numPollRequestRetries ??
           DEFAULT_POLL_CONFIG_REQUEST_RETRIES,
         pollAfterSuccessfulStart:
-          this.configurationRequestConfig.pollAfterSuccessfulInitialization ?? false,
+          this.configurationRequestParameters.pollAfterSuccessfulInitialization ?? false,
         pollAfterFailedStart:
-          this.configurationRequestConfig.pollAfterFailedInitialization ?? false,
-        errorOnFailedStart: this.configurationRequestConfig.throwOnFailedInitialization ?? false,
+          this.configurationRequestParameters.pollAfterFailedInitialization ?? false,
+        errorOnFailedStart:
+          this.configurationRequestParameters.throwOnFailedInitialization ?? false,
       },
     );