It’s possible to check that the ‘d’ property of the given path element is valid using isPathValid() function.
import { isPathValid } from 'mz-svg';
const isValid = isPathValid(`M 10,30
A 20,20 0,0,1 50,30
A 20,20 0,0,1 90,30
Q 90,60 50,90
Q 10,60 10,30 z`); // true
OR
import { isPathValid } from 'mz-svg';
const isValid = isPathValid(`M600,350 l 50,-25
a25,25 -30 1000,1 50,-25`); // false