[bug] diff("1.7.2-1", "1.8.1") returns patch, not minor

[erikjalevik]

Is there an existing issue for this?

• [X] I have searched the existing issues

Current Behavior

diff("1.7.2-1", "1.8.1") returns "patch".

Expected Behavior

I would have expected it to return "minor" since we're moving from 1.7 to 1.8.

Steps To Reproduce

1. In this environment...
2. With this config...
3. Run '...'
4. See error...

Environment

• npm:
• Node:
• OS:
• platform:

[wraithgar]

> Semver.inc('1.7.2-1', 'patch')
'1.7.2'
> Semver.inc('1.7.2-1', 'minor')
'1.8.0'
> Semver.diff("1.7.2", "1.8.1")
'minor'