+ * @returns The names of the worker's task functions.
+ */
+ public listTaskFunctionNames (): string[] {
+ const names: string[] = [...this.taskFunctions.keys()]
+ let defaultTaskFunctionName: string = DEFAULT_TASK_NAME
+ for (const [name, fn] of this.taskFunctions) {
+ if (
+ name !== DEFAULT_TASK_NAME &&
+ fn === this.taskFunctions.get(DEFAULT_TASK_NAME)
+ ) {
+ defaultTaskFunctionName = name
+ break
+ }
+ }
+ return [
+ names[names.indexOf(DEFAULT_TASK_NAME)],
+ defaultTaskFunctionName,
+ ...names.filter(
+ name => name !== DEFAULT_TASK_NAME && name !== defaultTaskFunctionName
+ )
+ ]
+ }
+
+ /**
+ * Sets the default task function to use in the worker.
+ *
+ * @param name - The name of the task function to use as default task function.
+ * @returns Whether the default task function was set or not.
+ */
+ public setDefaultTaskFunction (name: string): TaskFunctionOperationResult {
+ try {
+ checkTaskFunctionName(name)
+ if (name === DEFAULT_TASK_NAME) {
+ throw new Error(
+ 'Cannot set the default task function reserved name as the default task function'
+ )
+ }
+ if (!this.taskFunctions.has(name)) {
+ throw new Error(
+ 'Cannot set the default task function to a non-existing task function'
+ )
+ }
+ this.taskFunctions.set(
+ DEFAULT_TASK_NAME,
+ this.taskFunctions.get(name) as TaskFunction<Data, Response>
+ )
+ this.sendTaskFunctionNamesToMainWorker()
+ return { status: true }
+ } catch (error) {
+ return { status: false, error: error as Error }
+ }
+ }
+
+ /**
+ * Handles the ready message sent by the main worker.
+ *
+ * @param message - The ready message.
+ */
+ protected abstract handleReadyMessage (message: MessageValue<Data>): void
+
+ /**
+ * Worker message listener.
+ *
+ * @param message - The received message.
+ */
+ protected messageListener (message: MessageValue<Data>): void {
+ this.checkMessageWorkerId(message)
+ if (message.statistics != null) {
+ // Statistics message received
+ this.statistics = message.statistics
+ } else if (message.checkActive != null) {
+ // Check active message received
+ message.checkActive ? this.startCheckActive() : this.stopCheckActive()
+ } else if (message.taskFunctionOperation != null) {
+ // Task function operation message received
+ this.handleTaskFunctionOperationMessage(message)
+ } else if (message.taskId != null && message.data != null) {
+ // Task message received
+ this.run(message)
+ } else if (message.kill === true) {
+ // Kill message received
+ this.handleKillMessage(message)
+ }
+ }
+
+ protected handleTaskFunctionOperationMessage (
+ message: MessageValue<Data>
+ ): void {
+ const { taskFunctionOperation, taskFunctionName, taskFunction } = message
+ let response!: TaskFunctionOperationResult
+ switch (taskFunctionOperation) {
+ case 'add':
+ response = this.addTaskFunction(
+ taskFunctionName as string,
+ // eslint-disable-next-line @typescript-eslint/no-implied-eval, no-new-func
+ new Function(`return ${taskFunction as string}`)() as TaskFunction<
+ Data,
+ Response
+ >
+ )
+ break
+ case 'remove':
+ response = this.removeTaskFunction(taskFunctionName as string)
+ break
+ case 'default':
+ response = this.setDefaultTaskFunction(taskFunctionName as string)
+ break
+ default:
+ response = { status: false, error: new Error('Unknown task operation') }
+ break
+ }
+ this.sendToMainWorker({
+ taskFunctionOperation,
+ taskFunctionOperationStatus: response.status,
+ taskFunctionName,
+ ...(!response.status &&
+ response?.error != null && {
+ workerError: {
+ name: taskFunctionName as string,
+ message: this.handleError(response.error as Error | string)
+ }
+ })
+ })
+ }
+
+ /**
+ * Handles a kill message sent by the main worker.
+ *
+ * @param message - The kill message.
+ */
+ protected handleKillMessage (_message: MessageValue<Data>): void {
+ this.stopCheckActive()
+ if (isAsyncFunction(this.opts.killHandler)) {
+ (this.opts.killHandler?.() as Promise<void>)
+ .then(() => {
+ this.sendToMainWorker({ kill: 'success' })
+ return undefined
+ })
+ .catch(() => {
+ this.sendToMainWorker({ kill: 'failure' })
+ })
+ } else {
+ try {
+ // eslint-disable-next-line @typescript-eslint/no-invalid-void-type
+ this.opts.killHandler?.() as void
+ this.sendToMainWorker({ kill: 'success' })
+ } catch {
+ this.sendToMainWorker({ kill: 'failure' })
+ }
+ }
+ }
+
+ /**
+ * Check if the message worker id is set and matches the worker id.
+ *
+ * @param message - The message to check.
+ * @throws {@link https://nodejs.org/api/errors.html#class-error} If the message worker id is not set or does not match the worker id.
+ */
+ private checkMessageWorkerId (message: MessageValue<Data>): void {
+ if (message.workerId == null) {
+ throw new Error('Message worker id is not set')
+ } else if (message.workerId !== this.id) {
+ throw new Error(
+ `Message worker id ${message.workerId} does not match the worker id ${this.id}`
+ )
+ }
+ }
+
+ /**
+ * Starts the worker check active interval.