Support wildcards in versions

[alexandernst]

This implements #24

The code will expand wildcards inside versions following these rules:

* when dealing with patch wildcards:
>= 1.2.x    will become    >= 1.2.0
<= 1.2.x    will become    <  1.3.0
>  1.2.x    will become    >= 1.3.0
<  1.2.x    will become    <  1.2.0
!= 1.2.x    will become    <  1.2.0 >= 1.3.0
* when dealing with minor wildcards:
>= 1.x      will become    >= 1.0.0
<= 1.x      will become    <  2.0.0
>  1.x      will become    >= 2.0.0
<  1.0      will become    <  1.0.0
!= 1.x      will become    <  1.0.0 >= 2.0.0
* when dealing with wildcards without version operator:
1.2.x       will become    >= 1.2.0 < 1.3.0
1.x         will become    >= 1.0.0 < 2.0.0

[blang]

Thank you very much, looks good at the first impression, please give me some time to review this, since i'm quite busy in the next couple of days

[alexandernst]

Take your time @blang ;)
The same as with the other PR, if you feel that something is missing or you need me to do something extra, ask and I'll do it.

[alexandernst]

@blang Any news on this? :)

[blang]

I finally found some time to look into it, here are a couple of points that caught my attention:

• There are no end2end tests (TestParseRange)
• No full test coverage
• use constants and iota for constants:

type wildcardType int

const (
	noneWildcard wildcardType = iota
	majorWildcard
	minorWildcard
	patchWildcard
)

[blang]

Might not work for prerelease and build metadata version information since it may contain dots like '1.0.0-1.x.x' which is a valid version:
http://semver.org/#spec-item-9

[blang]

That's only an issue if pr and build metadata versions are allowed as ranges, sadly i haven't written tests for that case in the first place, therefor that's open for discussion

[alexandernst]

That can't happen as getWildcardType is executed on each splitted version, meaning that, with your example, getWildcardType will be called with 1.0.0 and 1.x.x.

[alexandernst]

@blang I wrote more tests to push the code coverage to 100% and I wrote end2end tests for the ParseRange function. I also replied to the concern you have about the getWildcardType function misbehaving with wrong parameters. Can you check the new commits, please?

[blang]

LGTM, thanks, good work