net/url: add URL.Hostname and URL.Port accessors

Fixes #16142

Change-Id: I7609faaf00c69646b0bd44a60a63a22d9265feb0
Reviewed-on: https://go-review.googlesource.com/28933
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Reviewed-by: Francesc Campoy Flores <campoy@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/net/url/url.go b/src/net/url/url.go
index 4a6253bdcc72c715741b8059413e909dc81cd45e..a0a2931c9ebc829ef63e128805749e460d0400e1 100644 (file)
--- a/src/net/url/url.go
+++ b/src/net/url/url.go
@@ -872,6 +872,7 @@ func resolvePath(base, ref string) string {
 }
 
 // IsAbs reports whether the URL is absolute.
+// Absolute means that it has a non-empty scheme.
 func (u *URL) IsAbs() bool {
        return u.Scheme != ""
 }
@@ -951,3 +952,43 @@ func (u *URL) RequestURI() string {
        }
        return result
 }
+
+// Hostname returns u.Host, without any port number.
+//
+// If Host is an IPv6 literal with a port number, Hostname returns the
+// IPv6 literal without the square brackets. IPv6 literals may include
+// a zone identifier.
+func (u *URL) Hostname() string {
+       return stripPort(u.Host)
+}
+
+// Port returns the port part of u.Host, without the leading colon.
+// If u.Host doesn't contain a port, Port returns an empty string.
+func (u *URL) Port() string {
+       return portOnly(u.Host)
+}
+
+func stripPort(hostport string) string {
+       colon := strings.IndexByte(hostport, ':')
+       if colon == -1 {
+               return hostport
+       }
+       if i := strings.IndexByte(hostport, ']'); i != -1 {
+               return strings.TrimPrefix(hostport[:i], "[")
+       }
+       return hostport[:colon]
+}
+
+func portOnly(hostport string) string {
+       colon := strings.IndexByte(hostport, ':')
+       if colon == -1 {
+               return ""
+       }
+       if i := strings.Index(hostport, "]:"); i != -1 {
+               return hostport[i+len("]:"):]
+       }
+       if strings.Contains(hostport, "]") {
+               return ""
+       }
+       return hostport[colon+len(":"):]
+}

diff --git a/src/net/url/url_test.go b/src/net/url/url_test.go
index 76e16812a5a03060d1562b11c059956a7cb606b5..73f5699152f23c7f18f08990257b16c2d983e282 100644 (file)
--- a/src/net/url/url_test.go
+++ b/src/net/url/url_test.go
@@ -1479,3 +1479,47 @@ func TestURLErrorImplementsNetError(t *testing.T) {
                }
        }
 }
+
+func TestURLHostname(t *testing.T) {
+       tests := []struct {
+               host string // URL.Host field
+               want string
+       }{
+               {"foo.com:80", "foo.com"},
+               {"foo.com", "foo.com"},
+               {"FOO.COM", "FOO.COM"}, // no canonicalization (yet?)
+               {"1.2.3.4", "1.2.3.4"},
+               {"1.2.3.4:80", "1.2.3.4"},
+               {"[1:2:3:4]", "1:2:3:4"},
+               {"[1:2:3:4]:80", "1:2:3:4"},
+               {"[::1]:80", "::1"},
+       }
+       for _, tt := range tests {
+               u := &URL{Host: tt.host}
+               got := u.Hostname()
+               if got != tt.want {
+                       t.Errorf("Hostname for Host %q = %q; want %q", tt.host, got, tt.want)
+               }
+       }
+}
+
+func TestURLPort(t *testing.T) {
+       tests := []struct {
+               host string // URL.Host field
+               want string
+       }{
+               {"foo.com", ""},
+               {"foo.com:80", "80"},
+               {"1.2.3.4", ""},
+               {"1.2.3.4:80", "80"},
+               {"[1:2:3:4]", ""},
+               {"[1:2:3:4]:80", "80"},
+       }
+       for _, tt := range tests {
+               u := &URL{Host: tt.host}
+               got := u.Port()
+               if got != tt.want {
+                       t.Errorf("Port for Host %q = %q; want %q", tt.host, got, tt.want)
+               }
+       }
+}