update

Author: raju-opti

lib/project_config/project_config_manager.ts

@@ -14,9 +14,6 @@
  * limitations under the License.
  */
 import { LoggerFacade } from '../modules/logging';
-import { sprintf } from '../utils/fns';
-
-import { ERROR_MESSAGES } from '../utils/enums';
 import { createOptimizelyConfig } from '../core/optimizely_config';
 import {  OptimizelyConfig } from '../shared_types';
 import { DatafileManager } from './datafile_manager';
@@ -44,8 +41,8 @@ export interface ProjectConfigManager extends Service {
 
 /**
  * ProjectConfigManager provides project config objects via its methods
- * getConfig and onUpdate. It uses a DatafileManager to fetch datafiles. It is
- * responsible for parsing and validating datafiles, and converting datafile
+ * getConfig and onUpdate. It uses a DatafileManager to fetch datafile if provided.
+ * It is responsible for parsing and validating datafiles, and converting datafile
  * string into project config objects.
  * @param {ProjectConfigManagerConfig}    config
  */
@@ -87,6 +84,10 @@ export class ProjectConfigManagerImpl extends BaseService implements ProjectConf
     }
 
     this.datafileManager?.start();
+
+    // This handles the case where the datafile manager starts successfully. The 
+    // datafile manager will only start successfully when it has downloaded a datafile,
+    // an will fire an onUpdate event.
     this.datafileManager?.onUpdate(this.handleNewDatafile.bind(this));
 
     // If the datafile manager runs successfully, it will emit a onUpdate event. We can
@@ -105,20 +106,14 @@ export class ProjectConfigManagerImpl extends BaseService implements ProjectConf
     this.stopPromise.reject(error);
   }
 
-  /**
-   * Respond to datafile manager's onRunning promise becoming rejected.
-   * When DatafileManager's onReady promise is rejected, if a datafile was not provided and therefore
-   * the projectConfigManager is still in New state, there is no possibility
-   * of obtaining a datafile. In this case, ProjectConfigManager's ready promise
-   * is fulfilled with an unsuccessful result.
-   */
   private handleDatafileManagerError(err: Error): void {
     // TODO: replace message with imported constants
     this.logger?.error('datafile manager failed to start', err);
 
     // If datafile manager onRunning() promise is rejected, and the project config manager 
-    // is still in starting state, that means a datafile was not provided or was invalid.
-    // In this case, we cannot recover and must reject the start promise.
+    // is still in starting state, that means a datafile was not provided in cofig or was invalid, 
+    // otherwise the state would have already been set to running synchronously.
+    // In this case, we cannot recover.
     if (this.isStarting()) {
       this.handleInitError(err);
     }
@@ -127,8 +122,9 @@ export class ProjectConfigManagerImpl extends BaseService implements ProjectConf
   /**
    * Handle new datafile by attemping to create a new Project Config object. If successful and
    * the new config object's revision is newer than the current one, sets/updates the project config
-   * and optimizely config object instance variables and returns null for the error. If unsuccessful,
-   * the project config and optimizely config objects will not be updated, and the error is returned.
+   * and emits onUpdate event. If unsuccessful,
+   * the project config and optimizely config objects will not be updated. If the error
+   * is fatal, handleInitError will be called.
    */
   private handleNewDatafile(newDatafile: string | object, fromConfig = false): void {
     if (this.isDone()) {
@@ -193,9 +189,6 @@ export class ProjectConfigManagerImpl extends BaseService implements ProjectConf
     return this.eventEmitter.on('update', listener);
   }
 
-  /**
-   * Stop the internal datafile manager and remove all update listeners
-   */
   stop(): void {
     if (this.isDone()) {
       return;

lib/service.ts

@@ -35,8 +35,14 @@ export enum ServiceState {
 export interface Service {
   getState(): ServiceState;
   start(): void;
+  // onRunning will reject if the service fails to start
+  // or stopped before it could start.
+  // It will resolve if the service is starts successfully.
   onRunning(): Promise<void>;
   stop(): void;
+  // onTerminated will reject if the service enters a failed state
+  // either by failing to start or stop.
+  // It will resolve if the service is stopped successfully.
   onTerminated(): Promise<void>;
 }
 

lib/utils/repeater/repeater.ts

@@ -17,9 +17,19 @@
 import { AsyncTransformer } from "../type";
 import { scheduleMicrotask } from "../microtask";
 
+// A repeater will invoke the task repeatedly. The time at which the task is invoked
+// is determined by the implementation.
+// The task is a function that takes a number as an argument and returns a promise.
+// The number argument is the number of times the task previously failed consecutively.
+// If the retuned promise resolves, the repeater will assume the task succeeded,
+// and will reset the failure count. If the promise is rejected, the repeater will
+// assume the task failed and will increase the current consecutive failure count.
 export interface Repeater {
+  // If immediateExecution is true, the first exection of 
+  // the task will be immediate but asynchronous.
   start(immediateExecution?: boolean): void;
   stop(): void;
+  reset(): void;
   setTask(task: AsyncTransformer<number, void>): void;
 }
 
@@ -52,6 +62,12 @@ export class ExponentialBackoff implements BackoffController {
   }
 }
 
+// IntervalRepeater is a Repeater that invokes the task at a fixed interval 
+// after the completion of the previous task invocation. If a backoff controller
+// is provided, the repeater will use the backoff controller to determine the
+// time between invocations after a failure instead. It will reset the backoffController
+// on success.
+
 export class IntervalRepeater implements Repeater {
   private timeoutId?: NodeJS.Timeout;
   private task?: AsyncTransformer<number, void>;

vitest.config.mts

@@ -20,7 +20,7 @@ export default defineConfig({
   test: {
     onConsoleLog: () => true,
     environment: 'happy-dom',
-    include: ['**/project_config_manager.spec.ts'],
+    include: ['**/*.spec.ts'],
     typecheck: {
       tsconfig: 'tsconfig.spec.json',
     },