unicorn-utterances/src/utils/url-paths.ts

import slash from "slash";

/**
 * Matches:
 * - ftp://
 * - https://
 * - //
 */
export const absolutePathRegex = /^(?:[a-z]+:)?\/\//;

export const isRelativePath = (str: string) => {
	const isAbsolute = absolutePathRegex.exec(str);
	if (isAbsolute) return false;
	return true;
};

const pathJoin = function (...pathArr) {
	return pathArr
		.map(function (path) {
			if (path[0] === "/") {
				path = path.slice(1);
			}
			if (path.startsWith("./")) {
				path = path.slice(2);
			}
			if (path[path.length - 1] === "/") {
				path = path.slice(0, path.length - 1);
			}
			return path;
		})
		.join("/");
};

export const getFullRelativePath = (...paths: string[]) => {
	return isRelativePath(paths[paths.length - 1])
		? slash(pathJoin(...paths))
		: paths[paths.length - 1];
};

export const trimTrailingSlash = (path: string) => {
	if (path.endsWith("/")) return path.slice(0, path.length - 1);
	return path;
};