utils.ts•2.45 kB
import type { AnyNode } from 'domhandler';
import type { Cheerio } from './cheerio.js';
/**
* Checks if an object is a Cheerio instance.
*
* @category Utils
* @param maybeCheerio - The object to check.
* @returns Whether the object is a Cheerio instance.
*/
export function isCheerio<T>(maybeCheerio: any): maybeCheerio is Cheerio<T> {
return maybeCheerio.cheerio != null;
}
/**
* Convert a string to camel case notation.
*
* @private
* @category Utils
* @param str - The string to be converted.
* @returns String in camel case notation.
*/
export function camelCase(str: string): string {
return str.replace(/[._-](\w|$)/g, (_, x) => x.toUpperCase());
}
/**
* Convert a string from camel case to "CSS case", where word boundaries are
* described by hyphens ("-") and all characters are lower-case.
*
* @private
* @category Utils
* @param str - The string to be converted.
* @returns String in "CSS case".
*/
export function cssCase(str: string): string {
return str.replace(/[A-Z]/g, '-$&').toLowerCase();
}
/**
* Iterate over each DOM element without creating intermediary Cheerio
* instances.
*
* This is indented for use internally to avoid otherwise unnecessary memory
* pressure introduced by _make.
*
* @category Utils
* @param array - The array to iterate over.
* @param fn - Function to call.
* @returns The original instance.
*/
export function domEach<
T extends AnyNode,
Arr extends ArrayLike<T> = Cheerio<T>,
>(array: Arr, fn: (elem: T, index: number) => void): Arr {
const len = array.length;
for (let i = 0; i < len; i++) fn(array[i], i);
return array;
}
const enum CharacterCodes {
LowerA = 97,
LowerZ = 122,
UpperA = 65,
UpperZ = 90,
Exclamation = 33,
}
/**
* Check if string is HTML.
*
* Tests for a `<` within a string, immediate followed by a letter and
* eventually followed by a `>`.
*
* @private
* @category Utils
* @param str - The string to check.
* @returns Indicates if `str` is HTML.
*/
export function isHtml(str: string): boolean {
const tagStart = str.indexOf('<');
if (tagStart < 0 || tagStart > str.length - 3) return false;
const tagChar = str.charCodeAt(tagStart + 1);
return (
((tagChar >= CharacterCodes.LowerA && tagChar <= CharacterCodes.LowerZ) ||
(tagChar >= CharacterCodes.UpperA && tagChar <= CharacterCodes.UpperZ) ||
tagChar === CharacterCodes.Exclamation) &&
str.includes('>', tagStart + 2)
);
}