immer-peasy/src/scope.js

Easy Peasy friendly modification of immer

import {DRAFT_STATE} from "./common"

/** Each scope represents a `produce` call. */
export class ImmerScope {
    constructor(parent) {
        this.drafts = []
        this.parent = parent

        // Whenever the modified draft contains a draft from another scope, we
        // need to prevent auto-freezing so the unowned draft can be finalized.
        this.canAutoFreeze = true

        // To avoid prototype lookups:
        this.patches = null
    }
    usePatches(patchListener) {
        if (patchListener) {
            this.patches = []
            this.inversePatches = []
            this.patchListener = patchListener
        }
    }
    revoke() {
        this.leave()
        this.drafts.forEach(revoke)
        this.drafts = null // Make draft-related methods throw.
    }
    leave() {
        if (this === ImmerScope.current) {
            ImmerScope.current = this.parent
        }
    }
}

ImmerScope.current = null
ImmerScope.enter = function() {
    return (this.current = new ImmerScope(this.current))
}

function revoke(draft) {
    draft[DRAFT_STATE].revoke()
}