Function urlValidateFn

src/lib/validate-util.ts:103–137

(options?: URLValidateFnOptions)

const allowedHTTPHosts = ['localhost', '127.0.0.1']
export const urlValidateFn = (options?: URLValidateFnOptions): ValidateFunction<string> => {
	return (input: string): true | string => {
		try {
			const url = new URL(input)
			// Invalid URLs with only a single `/` get parsed fine by `new URL` but of course are not
			// accepted by APIs so we test specifically for that here.
			if (!input.match(/^\w+:\/\//)) {
				throw { code: 'ERR_INVALID_URL' }
			}
			if (url.port) {
				const minPort = options?.minPort ?? 1
				const maxPort = options?.maxPort ?? 65535
				const portNum = parseInt(url.port)
				if (portNum < minPort || portNum > maxPort) {
					return `Port must be between ${minPort} and ${maxPort} inclusive.`
				}
			}
			if (options?.httpsRequired) {
				if (options.allowLocalhostHTTP) {
					return url.protocol === 'https:' ||
						url.protocol === 'http:' && allowedHTTPHosts.includes(url.hostname) ||
						'https is required except for localhost'
				}
				return url.protocol === 'https:' || 'https protocol is required'
			}
			return url.protocol === 'https:' || url.protocol === 'http:' || 'http(s) protocol is required'
		} catch (error) {
			if (error.code === 'ERR_INVALID_URL') {
				return `must be a valid URL${options?.httpsRequired ? ' with https protocol' : ''}`
			} else {
				throw error
			}
		}
	}
}

// Email regex found on Stack Overflow:
//   https://stackoverflow.com/questions/201323/how-can-i-validate-an-email-address-using-a-regular-expression