Duplicate slashes "//" in urls when a part is empty

[crccheck]

url-join version 3.0.0

> urlJoin('path/', '', '/test')
'path/test'  # expected
'path//test' # actual

> urlJoin('path', '', /test')
'path/test'  # expected
'path//test' # actual

> urlJoin('path', null, /test')
'path/test'  # expected
'path//test' # actual

In more detail, I've got an array of bits of a url. Sometimes, parts are optional, so I set them to '' and assume the url joiner will throw away the empty bits

[crccheck]

ugh, submitted before I wrote the issue

[crccheck]

as prior art, this is the same behavior as Node's built in path.join:

$ node
> const path = require('path')
undefined
> path.join('hi')
'hi'
> path.join('hi', 'there')
'hi/there'
> path.join('hi', '', 'there')
'hi/there'

[jfromaniello]

Thanks for reporting this. I just published v4 addressing this the same way that path.join does.

[shellscape]

@jfromaniello this could have been documented much better than it is in the changelog. This also effects urlJoin('', 'foo.js');. Previously the return value was /foo.js, in version 4, it's foo.js. Folks that aren't aware of the nuances of path.join will be thrown off by this because of prior expected behavior of the module.

[crccheck]

ooh, I didn't even think of that use case. I'll try to keep that in mind in the future too. For reference, here's Node's path.join with some variations of that case:

> path.join('', 'foo.js')
'foo.js'
> path.join('', '/foo.js')
'/foo.js'
> path.join('/', 'foo.js')
'/foo.js'
> path.join('/', '/foo.js')
'/foo.js'

[jfromaniello]

I think I've reached a point in this library where every time I merge a PR I break someone else use case. I am trying to figure a way, I think to begin with we need a lot more of tests and specifications.