gistfile.txt

$ find . -type f
./docs/foo/thing.js
./docs/thing.js
./docs/nope.txt
./docs-src/foo/thing.js
./docs-src/thing.js
./x.sh
./client/docs/foo/thing.js
./client/docs/thing.js
./client/docs/nope.txt
./client/docs-src/foo/thing.js
./client/docs-src/thing.js
./client/docs-src/nope.txt
./client/nope.txt
./src/foo/thing.js
./src/thing.js

$ for i in ./!(docs)/**/*.js; do echo $i; done
./client/docs-src/foo/thing.js
./client/docs-src/thing.js
./client/docs/foo/thing.js
./client/docs/thing.js
./docs-src/foo/thing.js
./docs-src/thing.js
./src/foo/thing.js
./src/thing.js

$ node -p 'require("glob").sync("./!(docs)/**/*.js")'
[ './client/docs-src/foo/thing.js',
  './client/docs-src/thing.js',
  './client/docs/foo/thing.js',
  './client/docs/thing.js',
  './docs-src/foo/thing.js',
  './docs-src/thing.js',
  './src/foo/thing.js',
  './src/thing.js' ]