es-toolkit/dist/compat/_internal/isDeepKey.js

A state-of-the-art, high-performance JavaScript utility library with a small bundle size and strong type annotations.

//#region src/compat/_internal/isDeepKey.ts
/** Matches any deep property path. Examples: `a.b`, `a[0]`, `a["b"]` */
const regexIsDeepProp = /\.|(\[(?:[^[\]]*|(["'])(?:(?!\2)[^\\]|\\.)*?\2)\])/;
/**
* Checks if a given key is a deep key.
*
* A deep key is a string that contains a dot (.) or square brackets with a property accessor.
*
* @param {PropertyKey} key - The key to check.
* @returns {boolean} - Returns true if the key is a deep key, otherwise false.
*
* Examples:
*
* isDeepKey('a.b') // true
* isDeepKey('a[b]') // true
* isDeepKey('a') // false
* isDeepKey(123) // false
* isDeepKey('a.b.c') // true
* isDeepKey('a[b][c]') // true
* isDeepKey('a.') // false
* isDeepKey('.a') // false
* isDeepKey('a[b') // false
* isDeepKey('a]b]') // false
* isDeepKey('a][b') // false
* isDeepKey('') // false
* isDeepKey('a[0]') // true
*
*/
function isDeepKey(key) {
	switch (typeof key) {
		case "number":
		case "symbol": return false;
		case "string":
			if (key === "" || key.startsWith(".") || key.endsWith(".")) return false;
			return regexIsDeepProp.test(key);
		default: return false;
	}
}
//#endregion
exports.isDeepKey = isDeepKey;