Suggestion: `volta install node` should error if `node` is being shadowed by another binary in PATH

[untitaker]

volta setup takes care of volta being at the front of the path. However:

1. I hand-maintain my .profile
2. What if two programs did this?

Today I found out the answer to question 2. PATH contained additional binaries by other "shim" programs, and as a result volta's shim node was shadowed by another node

I believe volta, on every run of volta install, should check $PATH and ensure that the just-installed command actually resolves to the shim binary. The which crate can be used for this. If that isn't the case, volta should at least emit a warning, or even error. From a user POV, nothing was installed.

[untitaker]

if you agree that this would be a worthwhile UX improvement i'm interested in implementing

[charlespierce]

Hi @untitaker, thanks for the suggestion! I really like that idea since it neatly avoids showing unnecessary information to a user who explicitly shadowed Node: If they're running volta install node, then it's a reasonable assumption that they want Volta to be managing Node, which won't work if it's shadowed. It also provides the information right when it's most useful and gives us an opportunity to provide feedback for how to fix it.

We'd absolutely welcome a contribution that adds a warning when installing Node if the PATH has a different version of Node ahead of Volta. Let me know if you need any pointers around the code or anything to help!