Passing an invalid string as a URL to `pathTemplate` causes an exception.

[kako-jun]

To reproduce the exception:

in:

urlcat("http://example.com", "//");

out:

If a parameter appears twice in the path, it is substituted twice:
     TypeError [ERR_INVALID_URL]: Invalid URL: //

Users of urlcat may not know that new URL is called internally. So users don't expect exceptions.

The problem is when pathTemplate is variable. Users don't know what string cause an exception until they give it to urlcat. :cold_sweat:

It forces users to add try. Or users need to read the urlcat code to prevent this.

How is adding try internally :question:

[balazsbotond]

Nice catch, thank you!

This is indeed very unexpected behavior. I'll release a fix later today.

[balazsbotond]

This is due to how the URL constructor handles relative URLs:

new URL('/foo', 'http://example.com').toString() // ==> "http://example.com/foo"
new URL('', 'http://example.com').toString() // ==> "http://example.com/"
new URL('/', 'http://example.com').toString() // ==> "http://example.com/"
new URL('//foo', 'http://example.com').toString() // ==> "http://foo/"
new URL('//', 'http://example.com').toString() // ==> ERROR

To be honest I don't think this is useful at all - users would expect urlcat to do simple concatenation. This error goes against the principle of least surprise. We already have a well-tested join function that does the same so I'm going to replace the URL constructor with a simple join call.

[balazsbotond]

@kako-jun thanks again. I've fixed the bug and published a new patch release v2.0.2.

[balazsbotond]

@all-contributors please add @kako-jun for bug

[allcontributors[bot]]

@balazsbotond

I've put up a pull request to add @kako-jun! :tada: