ls: show relative paths from root, not absolute

[isaacs]

Change the output in npm ls for symlink dependencies (including
workspaces) to show the relative path from the project root, rather than
the absolute path of the link target.

This makes the output much less noisy and more ergonomic when many
workspaces and link dependencies are in use, especially when paths are
long.

It is arguable that this output might be slightly misleading, since the
actual workspace symlink from ${root}/node_modules/b to
${root}/packages/b has a link value of ../packages/b, not just
packages/b. (Or on Windows, always the full absolute path, because
junctions.) Thus, npm ls b will not show the same output as ls -l node_modules/b.

However, npm ls shows the logical tree, not the physical tree, so
presenting the user with a path that they can use and interpret is more
important than presenting them with the strictly accurate details of
their filesystem.

References

[nlf]

i wonder if we should prefix the path with a ./ or something to make it as clear as possible that we're referring to a directory, the paths that output just a name like b@1.0.0 -> b read strangely to me

[ljharb]

That would follow the change node made (versus "main" or "bin") when adding "exports" - that relative paths always, and only, start with ..

[isaacs]

That would follow the change node made (versus "main" or "bin") when adding "exports" - that relative paths always, and only, start with .

It would be nice if Node.js's path.relative() had this behavior, but I suppose that's not something we could ever backport anyway. I'll fix up this patch to accommodate. I agree, that's much clearer.

[ljharb]

agreed; i have sooooo many `./${path.relative(…)}` instances in my code :-/