c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = 'test atest atested tested test- -test test .test test. test';
 ;;
 $s =~ s/\b(test)([^-])/DONE/g;
 print qq{'$s'};
"
'DONEatest atested DONEd test- -DONEDONE.DONEDONE test'

c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = 'test atest atested tested test- -test test .test test. test';
 ;;
 $s =~ s/\b(test)([^-]|$)/DONE/g;
 print qq{'$s'};
"
'DONEatest atested DONEd test- -DONEDONE.DONEDONE DONE'