Hi Efraim,

> Overall it looks good to me. I also checked npm¹ and it agrees that
> there are no dependencies for this package. Do you happen to know why
> there's a test directory installed? I don't know if it's supposed to be
> there but it seems strange to me

I didn't notice and I agree that tests shouldn't be installed but IIUC 
it's a limitation of the node-build-system that copies recursively the 
contents of the node_modules directory. I checked and it seems that 
other packages using the node-build-system have the same problem (i.e. 
node-color-name install test.js, node-far installs a test directory). 
One way to fix this could be adding an extra phase (either to each 
package or in the node-build-system with a special field indicating a 
list of tests directories) where we delete the test directory from  
node_modules preventing the copy.

On my system I get

orang3@frastanato ~/code/guix [env]$ du -sh 
/gnu/store/5kkb1nya9ws12b2qxsn0r7904nx6v5b5-node-semver-7.2.1
732K    /gnu/store/5kkb1nya9ws12b2qxsn0r7904nx6v5b5-node-semver-7.2.1

orang3@frastanato ~/code/guix [env]$ du -sh 
/gnu/store/5kkb1nya9ws12b2qxsn0r7904nx6v5b5-node-semver-7.2.1/lib/node_modules/semver/test/
264K    
/gnu/store/5kkb1nya9ws12b2qxsn0r7904nx6v5b5-node-semver-7.2.1/lib/node_modules/semver/test/

which is not much but amounts nearly to 1/3 of the total disk usage of 
semver. If you believe that another phase deleting the tests would be 
better I attached an attempt.

Giacomo