308_SYS_CONTEXT.pkg

declare
    sb2  varchar2(100);
    mock integer;
begin
    mock := mockplcursor.mocksql('SYS_CONTEXT');
    mock.returns('[["NN"]]');    
    plcursor.setup('mock@database');

    sb2 := sys_context('USERENV', 'OS_USER');
    if sb2 = 'NN' then
        dbms_output.put_line('OK');
    end if;
end;
/