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irreligious/node_modules/eslint-visitor-keys/lib/index.js

81 lines
2.1 KiB
JavaScript

/**
* @author Toru Nagashima <https://github.com/mysticatea>
* See LICENSE file in root directory for full license.
*/
"use strict";
const KEYS = require("./visitor-keys.json");
// Types.
const NODE_TYPES = Object.freeze(Object.keys(KEYS));
// Freeze the keys.
for (const type of NODE_TYPES) {
Object.freeze(KEYS[type]);
}
Object.freeze(KEYS);
// List to ignore keys.
const KEY_BLACKLIST = new Set([
"parent",
"leadingComments",
"trailingComments"
]);
/**
* Check whether a given key should be used or not.
* @param {string} key The key to check.
* @returns {boolean} `true` if the key should be used.
*/
function filterKey(key) {
return !KEY_BLACKLIST.has(key) && key[0] !== "_";
}
//------------------------------------------------------------------------------
// Public interfaces
//------------------------------------------------------------------------------
module.exports = Object.freeze({
/**
* Visitor keys.
* @type {{ [type: string]: string[] | undefined }}
*/
KEYS,
/**
* Get visitor keys of a given node.
* @param {Object} node The AST node to get keys.
* @returns {string[]} Visitor keys of the node.
*/
getKeys(node) {
return Object.keys(node).filter(filterKey);
},
// Disable valid-jsdoc rule because it reports syntax error on the type of @returns.
// eslint-disable-next-line valid-jsdoc
/**
* Make the union set with `KEYS` and given keys.
* @param {Object} additionalKeys The additional keys.
* @returns {{ [type: string]: string[] | undefined }} The union set.
*/
unionWith(additionalKeys) {
const retv = Object.assign({}, KEYS);
for (const type of Object.keys(additionalKeys)) {
if (retv.hasOwnProperty(type)) {
const keys = new Set(additionalKeys[type]);
for (const key of retv[type]) {
keys.add(key);
}
retv[type] = Object.freeze(Array.from(keys));
} else {
retv[type] = Object.freeze(Array.from(additionalKeys[type]));
}
}
return Object.freeze(retv);
}
});