url.resolve() behaves differently depending on the protocol of the base url

[rolinh]

• Version: v4.5.0, v6.7.0
• Platform: Linux 3.16.0-76-generic x86_64, Linux 4.7.6-1-ARCH x86_64, FreeBSD 10.1-RELEASE-p26 amd64
• Subsystem: url

The url.resolve() function behaves differently depending on the protocol given in the from parameter.
See this example:

> var url = require("url");
undefined
> url.resolve("https://foo.tld", "bar");
'https://foo.tld/bar'
> url.resolve("wss://foo.tld", "bar");
'wss://bar'
> url.resolve("ftps://foo.tld", "bar");
'ftps://bar'

When reading this function's documentation, this is not a behavior that I could foresee. I would have expected 'wss://foo.tld/bar' and 'ftps://foo.tld/bar' as results of the last two calls respectively.

[bnoordhuis]

Some protocols (http, https, file, ftp and, yes, gopher) are treated specially, to match browser behavior ca. 2010, when the url module was introduced.

I think it's confusing but it's probably hard to change because of backwards compatibility. It's more likely to simply be subsumed by WHATWG URL support, ref #7448.

EDIT: Forgot to mention, if the URLs end in a slash, you get uniform behavior. I'll add documentation tags.

[rolinh]

Thanks @bnoordhuis. I believe that the information you give in your comment (the list of protocols which are treated specially and the uniform behavior when the URL ends with a slash) definitely has its place in the documentation.

[fhinkel]

Assigned to myself as placeholder for @minervapanda

[minervapanda]

According to my knowledge , the issue is pointing to the url.md to the following lines of url.resolve() : url.resolve('/one/two/three', 'four') // '/one/two/four'
url.resolve('http://example.com/', '/one') // 'http://example.com/one'
url.resolve('http://example.com/one', '/two') // 'http://example.com/two'

It looks good to me. Please correct me if I am wrong.

[rolinh]

@minervapanda Yes, the issue is pointing to these lines and the examples are correct. However, the documentation does not tell that:

• Some protocols are treated as special cases (http, https, file, ftp and gopher).
• The way in which these protocols are treated differently.
• The behavior of url.resolve() differs whether the URL ends with a / or not.

[minervapanda]

Thank you for the clarification @rolinh . I was confused ,the example seemed correct.I will make a PR to update the documentation.Thanks.