/usr/lib/R/site-library/stringr/tests/ is in r-cran-stringr 0.6.2-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/R/site-library/stringr/tests/test-check.r
/usr/lib/R/site-library/stringr/tests/test-count.r
/usr/lib/R/site-library/stringr/tests/test-detect.r
/usr/lib/R/site-library/stringr/tests/test-dup.r
/usr/lib/R/site-library/stringr/tests/test-extract.r
/usr/lib/R/site-library/stringr/tests/test-join.r
/usr/lib/R/site-library/stringr/tests/test-length.r
/usr/lib/R/site-library/stringr/tests/test-locate.r
/usr/lib/R/site-library/stringr/tests/test-match.r
/usr/lib/R/site-library/stringr/tests/test-pad.r
/usr/lib/R/site-library/stringr/tests/test-split.r
/usr/lib/R/site-library/stringr/tests/test-sub.r
/usr/lib/R/site-library/stringr/tests/test-trim.r