The Go linter no-sprintf-host-port checks that sprintf is not used to construct a host:port combination in a URL. A frequent pattern is for a developer to construct a URL like this:
fmt.Sprintf("http://%s:%d/foo", host, port)However, if "host" is an IPv6 address like 2001:4860:4860::8888, the
URL constructed will be invalid. IPv6 addresses must be bracketed, like this:
http://[2001:4860:4860::8888]:9443
The linter is naive, and really only looks for the most obvious cases, but where
it's possible to infer that a URL is being constructed with Sprintf containing a :,
this informs the user to use net.JoinHostPort instead.
Based on the go-printf-func-name linter,
and this article.