(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
typeof define === 'function' && define.amd ? define(['exports'], factory) :
(global = global || self, factory(global.estreeWalker = {}));
}(this, (function (exports) { 'use strict';
// @ts-check
/** @typedef { import('estree').BaseNode} BaseNode */
/** @typedef {{
skip: () => void;
remove: () => void;
replace: (node: BaseNode) => void;
}} WalkerContext */
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];
}
}
}
}
// @ts-check
/** @typedef { import('estree').BaseNode} BaseNode */
/** @typedef { import('./walker.js').WalkerContext} WalkerContext */
/** @typedef {(
* this: WalkerContext,
* node: BaseNode,
* parent: BaseNode,
* key: string,
* index: number
* ) => void} SyncHandler */
class SyncWalker extends WalkerBase {
/**
*
* @param {SyncHandler} enter
* @param {SyncHandler} leave
*/
constructor(enter, leave) {
super();
/** @type {SyncHandler} */
this.enter = enter;
/** @type {SyncHandler} */
this.leave = leave;
}
/**
*
* @param {BaseNode} node
* @param {BaseNode} parent
* @param {string} [prop]
* @param {number} [index]
* @returns {BaseNode}
*/
visit(node, parent, prop, index) {
if (node) {
if (this.enter) {
const _should_skip = this.should_skip;
const _should_remove = this.should_remove;
const _replacement = this.replacement;
this.should_skip = false;
this.should_remove = false;
this.replacement = null;
this.enter.call(this.context, node, parent, prop, index);
if (this.replacement) {
node = this.replacement;
this.replace(parent, prop, index, node);
}
if (this.should_remove) {
this.remove(parent, prop, index);
}
const skipped = this.should_skip;
const removed = this.should_remove;
this.should_skip = _should_skip;
this.should_remove = _should_remove;
this.replacement = _replacement;
if (skipped) return node;
if (removed) return null;
}
for (const key in node) {
const value = node[key];
if (typeof value !== "object") {
continue;
} else if (Array.isArray(value)) {
for (let i = 0; i < value.length; i += 1) {
if (value[i] !== null && typeof value[i].type === 'string') {
if (!this.visit(value[i], node, key, i)) {
// removed
i--;
}
}
}
} else if (value !== null && typeof value.type === "string") {
this.visit(value, node, key, null);
}
}
if (this.leave) {
const _replacement = this.replacement;
const _should_remove = this.should_remove;
this.replacement = null;
this.should_remove = false;
this.leave.call(this.context, node, parent, prop, index);
if (this.replacement) {
node = this.replacement;
this.replace(parent, prop, index, node);
}
if (this.should_remove) {
this.remove(parent, prop, index);
}
const removed = this.should_remove;
this.replacement = _replacement;
this.should_remove = _should_remove;
if (removed) return null;
}
}
return node;
}
}
// @ts-check
/** @typedef { import('estree').BaseNode} BaseNode */
/** @typedef { import('./walker').WalkerContext} WalkerContext */
/** @typedef {(
* this: WalkerContext,
* node: BaseNode,
* parent: BaseNode,
* key: string,
* index: number
* ) => Promise<void>} AsyncHandler */
class AsyncWalker extends WalkerBase {
/**
*
* @param {AsyncHandler} enter
* @param {AsyncHandler} leave
*/
constructor(enter, leave) {
super();
/** @type {AsyncHandler} */
this.enter = enter;
/** @type {AsyncHandler} */
this.leave = leave;
}
/**
*
* @param {BaseNode} node
* @param {BaseNode} parent
* @param {string} [prop]
* @param {number} [index]
* @returns {Promise<BaseNode>}
*/
async visit(node, parent, prop, index) {
if (node) {
if (this.enter) {
const _should_skip = this.should_skip;
const _should_remove = this.should_remove;
const _replacement = this.replacement;
this.should_skip = false;
this.should_remove = false;
this.replacement = null;
await this.enter.call(this.context, node, parent, prop, index);
if (this.replacement) {
node = this.replacement;
this.replace(parent, prop, index, node);
}
if (this.should_remove) {
this.remove(parent, prop, index);
}
const skipped = this.should_skip;
const removed = this.should_remove;
this.should_skip = _should_skip;
this.should_remove = _should_remove;
this.replacement = _replacement;
if (skipped) return node;
if (removed) return null;
}
for (const key in node) {
const value = node[key];
if (typeof value !== "object") {
continue;
} else if (Array.isArray(value)) {
for (let i = 0; i < value.length; i += 1) {
if (value[i] !== null && typeof value[i].type === 'string') {
if (!(await this.visit(value[i], node, key, i))) {
// removed
i--;
}
}
}
} else if (value !== null && typeof value.type === "string") {
await this.visit(value, node, key, null);
}
}
if (this.leave) {
const _replacement = this.replacement;
const _should_remove = this.should_remove;
this.replacement = null;
this.should_remove = false;
await this.leave.call(this.context, node, parent, prop, index);
if (this.replacement) {
node = this.replacement;
this.replace(parent, prop, index, node);
}
if (this.should_remove) {
this.remove(parent, prop, index);
}
const removed = this.should_remove;
this.replacement = _replacement;
this.should_remove = _should_remove;
if (removed) return null;
}
}
return node;
}
}
// @ts-check
/** @typedef { import('estree').BaseNode} BaseNode */
/** @typedef { import('./sync.js').SyncHandler} SyncHandler */
/** @typedef { import('./async.js').AsyncHandler} AsyncHandler */
/**
*
* @param {BaseNode} ast
* @param {{
* enter?: SyncHandler
* leave?: SyncHandler
* }} walker
* @returns {BaseNode}
*/
function walk(ast, { enter, leave }) {
const instance = new SyncWalker(enter, leave);
return instance.visit(ast, null);
}
/**
*
* @param {BaseNode} ast
* @param {{
* enter?: AsyncHandler
* leave?: AsyncHandler
* }} walker
* @returns {Promise<BaseNode>}
*/
async function asyncWalk(ast, { enter, leave }) {
const instance = new AsyncWalker(enter, leave);
return await instance.visit(ast, null);
}
exports.asyncWalk = asyncWalk;
exports.walk = walk;
Object.defineProperty(exports, '__esModule', { value: true });
})));
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