Yes.
A test or professional trial preceding possible conclusion of an employment contract (with or without a probationary clause) is not provided for by law and is therefore likewise not prohibited. An employer may arrange for candidates to take tests or professional trials to verify his skills and knowledge.
Such testing prior to conclusion of the employment contract is not, however, to be confused with the probationary period which may follow the conclusion of the employment contract.
A professional trial, inherently of short duration, is similar to an examination assessed by the employer, who is free to decide whether or not to recruit the candidate.
A professional trial must not, however, be used as a pretext for making a candidate perform work.
Work carried out in return for a salary (productive and subordinate work) would give rise to redeployment of the situation.