Testing Go module updates

testing_module_updates.md

So when we updated a few Go libraries, we wanted to run all the relevant tests... but not ALL tests. I thought this shell script one of my co-workers (@csilvers) used was very clever and handy:

git grep -l -e opentelemetry -e otelsql  '*.go' | grep -v testdata | xargs -n1 dirname | sed 's,^,./,' | sort -u | xargs gotestsum

Walking through what it does:

• git-grep -l, --files-with-matches, -e <pattern>
• grep -v, --invert-match Invert the sense of matching, to select non-matching lines. (exclude testdata dir matches)
• xargs -n max-args Use at most max-args arguments per command line. Fewer than max-args arguments will be used if the size (see the -s option) is exceeded, unless the -x option is given, in which case xargs will exit.
• dirname - strip last component from file name
• sed 's,^,./,' - prefix ./ to beginning of all lines e.g. services/users/resolvers becomes ./services/users/resolvers
• sort -u, --unique - sort lines of text files, output only the first of an equal run
• xargs - build and execute command lines from standard input