-export type Draft<T> = { -readonly [P in keyof T]?: T[P] }
-
-export interface MessageValue<Data> {
- readonly data?: Data
- readonly id?: number
- readonly kill?: number
- readonly error?: string
- readonly parent?: MessagePort
+import type { EventLoopUtilization } from 'node:perf_hooks'
+import type { KillBehavior } from './worker/worker-options'
+import type { IWorker, Task } from './pools/worker'
+
+/**
+ * Task error.
+ *
+ * @typeParam Data - Type of data sent to the worker triggering an error. This can only be structured-cloneable data.
+ */
+export interface TaskError<Data = unknown> {
+ /**
+ * Error message.
+ */
+ message: string
+ /**
+ * Data passed to the worker triggering the error.
+ */
+ data?: Data
+}
+
+/**
+ * Task performance.
+ */
+export interface TaskPerformance {
+ /**
+ * Task performance timestamp.
+ */
+ timestamp: number
+ /**
+ * Task runtime.
+ */
+ runTime?: number
+ /**
+ * Task event loop utilization.
+ */
+ elu?: EventLoopUtilization
+}
+
+/**
+ * Performance statistics computation.
+ */
+export interface WorkerStatistics {
+ runTime: boolean
+ elu: boolean
+}
+
+/**
+ * Message object that is passed between main worker and worker.
+ *
+ * @typeParam Data - Type of data sent to the worker or execution response. This can only be structured-cloneable data.
+ * @typeParam ErrorData - Type of data sent to the worker triggering an error. This can only be structured-cloneable data.
+ * @internal
+ */
+export interface MessageValue<Data = unknown, ErrorData = unknown>
+ extends Task<Data> {
+ /**
+ * Kill code.
+ */
+ readonly kill?: KillBehavior | 1
+ /**
+ * Task error.
+ */
+ readonly taskError?: TaskError<ErrorData>
+ /**
+ * Task performance.
+ */
+ readonly taskPerformance?: TaskPerformance
+ /**
+ * Whether the worker computes the given statistics or not.
+ */
+ readonly statistics?: WorkerStatistics
+}
+
+/**
+ * An object holding the execution response promise resolve/reject callbacks.
+ *
+ * @typeParam Worker - Type of worker.
+ * @typeParam Response - Type of execution response. This can only be structured-cloneable data.
+ * @internal
+ */
+export interface PromiseResponseWrapper<
+ Worker extends IWorker,
+ Response = unknown
+> {
+ /**
+ * Resolve callback to fulfill the promise.
+ */
+ readonly resolve: (value: Response) => void
+ /**
+ * Reject callback to reject the promise.
+ */
+ readonly reject: (reason?: string) => void
+ /**
+ * The worker handling the execution.
+ */
+ readonly worker: Worker
}