source: node_modules/immer/src/utils/plugins.ts

import {
        ImmerState,
        Patch,
        Drafted,
        ImmerBaseState,
        AnyMap,
        AnySet,
        ArchType,
        die
} from "../internal"

/** Plugin utilities */
const plugins: {
        Patches?: {
                generatePatches_(
                        state: ImmerState,
                        basePath: PatchPath,
                        patches: Patch[],
                        inversePatches: Patch[]
                ): void
                generateReplacementPatches_(
                        base: any,
                        replacement: any,
                        patches: Patch[],
                        inversePatches: Patch[]
                ): void
                applyPatches_<T>(draft: T, patches: readonly Patch[]): T
        }
        MapSet?: {
                proxyMap_<T extends AnyMap>(target: T, parent?: ImmerState): T
                proxySet_<T extends AnySet>(target: T, parent?: ImmerState): T
        }
} = {}

type Plugins = typeof plugins

export function getPlugin<K extends keyof Plugins>(
        pluginKey: K
): Exclude<Plugins[K], undefined> {
        const plugin = plugins[pluginKey]
        if (!plugin) {
                die(0, pluginKey)
        }
        // @ts-ignore
        return plugin
}

export function loadPlugin<K extends keyof Plugins>(
        pluginKey: K,
        implementation: Plugins[K]
): void {
        if (!plugins[pluginKey]) plugins[pluginKey] = implementation
}
/** Map / Set plugin */

export interface MapState extends ImmerBaseState {
        type_: ArchType.Map
        copy_: AnyMap | undefined
        assigned_: Map<any, boolean> | undefined
        base_: AnyMap
        revoked_: boolean
        draft_: Drafted<AnyMap, MapState>
}

export interface SetState extends ImmerBaseState {
        type_: ArchType.Set
        copy_: AnySet | undefined
        base_: AnySet
        drafts_: Map<any, Drafted> // maps the original value to the draft value in the new set
        revoked_: boolean
        draft_: Drafted<AnySet, SetState>
}

/** Patches plugin */

export type PatchPath = (string | number)[]