source: node_modules/estree-walker/src/walker.js

// @ts-check
/** @typedef { import('estree').BaseNode} BaseNode */

/** @typedef {{
        skip: () => void;
        remove: () => void;
        replace: (node: BaseNode) => void;
}} WalkerContext */

export class WalkerBase {
        constructor() {
                /** @type {boolean} */
                this.should_skip = false;

                /** @type {boolean} */
                this.should_remove = false;

                /** @type {BaseNode | null} */
                this.replacement = null;

                /** @type {WalkerContext} */
                this.context = {
                        skip: () => (this.should_skip = true),
                        remove: () => (this.should_remove = true),
                        replace: (node) => (this.replacement = node)
                };
        }

        /**
         *
         * @param {any} parent
         * @param {string} prop
         * @param {number} index
         * @param {BaseNode} node
         */
        replace(parent, prop, index, node) {
                if (parent) {
                        if (index !== null) {
                                parent[prop][index] = node;
                        } else {
                                parent[prop] = node;
                        }
                }
        }

        /**
         *
         * @param {any} parent
         * @param {string} prop
         * @param {number} index
         */
        remove(parent, prop, index) {
                if (parent) {
                        if (index !== null) {
                                parent[prop].splice(index, 1);
                        } else {
                                delete parent[prop];
                        }
                }
        }
}