Person left Canada in 2020 and return in 2021

One of my client had a work permit and stayed in Canada in 2020 until July. She left Canada to get a Study permit and came back in June 2021. She had a employment income in 2020.
Is she considered as a full-year resident of Canada in 2020 ? or Does she need to file a final return
in 2020 then do the 2021 return as a newcomer?
She had an intention to continue to live in Canada and she left all her belongings and bank account before leaving.?

Thank you.