perl -pi -e "s/assert\.equal\(([^,]+), ('[^']*')\);/expect(\$1, 'to equal', \$2);/g;" test/*.js
perl -pi -e "s/assert\.isNotNull\(([^,]+)\);/expect(\$1, 'not to be null');/g;" test/*.js
perl -pi -e "s/assert\.isNull\(([^,]+)\);/expect(\$1, 'to be null');/g;" test/*.js
perl -pi -e "s/assert\.equal\(([^,]+),$/expect(\$1, 'to equal',/g;" test/*.js
perl -pi -e "s/assert\.instanceOf\(([^,]+),/expect(\$1, 'to be an',/g;" test/*.js
perl -pi -e "s/assert\.isFalse\((.*?)\);/expect(\$1, 'to be false');/g;" test/*.js
perl -pi -e "s/assert\.equal\((.*?)\.indexOf\(('[^']*')\), -1\);/expect(\$1, 'not to contain', \$2);/g;" test/*.js
perl -pi -e "s/assert\.notEqual\((.*?)\.indexOf\(('[^']*')\), -1\);/expect(\$1, 'to contain', \$2);/g;" test/*.js
perl -pi -e "s/assert\.isObject\((.*)\);/expect(\$1, 'to be an object');/g;" test/*.js
perl -pi -e "s/assert\.isArray\((.*)\);/expect(\$1, 'to be an array');/g;" test/*.js
perl -pi -e "s/assert\.equal\((.*), ([^,]+)\);/expect(\$1, 'to equal', \$2);/g;" test/*.js
perl -pi -e "s/assert\.deepEqual\((.*),$/expect(\$1, 'to equal',/g;" test/*.js
perl -pi -e "s/assert\.ok\((.*)\);/expect(\$1, 'to be ok');/" test/*.js
perl -pi -e "s/assert\.deepEqual\((.*), \[$/expect(\$1, 'to equal', \[/g;" test/*.js
perl -pi -e "s/assert\.deepEqual\((.*), (\[[^\]]*\])\);$/expect(\$1, 'to equal', \$2);/g;" test/*.js
perl -pi -e "s/assert\.match\((.*),$/expect(\$1, 'to match',/g;" test/*.js
perl -pi -e "s/assert\.matches\((.*),$/expect(\$1, 'to match',/g;" test/*.js
perl -pi -e "s/assert\.matches\((.*), (.*)\);?$/expect(\$1, 'to match', \$2);/g;" test/*.js
Converted the rest of the asserts by hand.