repospec: support ssh urls with ssh certificates

Organizations that use a custom SSH Certificate Authority with GitHub
Enterprise Cloud will have a host that starts with `org-12345@` instead
of `git@`. This removes the hard-coded `git@` in the repo spec parsing
for a regexp match on a valid username instead.

api/internal/git/repospec.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"net/url"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -195,18 +196,26 @@ func peelQuery(arg string) (string, string, time.Duration, bool) {
 	return parsed.Path, ref, duration, submodules
 }
 
+var userRegex = regexp.MustCompile(`^[a-zA-Z][a-zA-Z0-9-]*@`)
+
 func parseHostSpec(n string) (string, string) {
 	var host string
-	// Start accumulating the host part.
-	for _, p := range []string{
-		// Order matters here.
-		"git::", "gh:", "ssh://", "https://", "http://",
-		"git@", "github.com:", "github.com/"} {
-		if len(p) < len(n) && strings.ToLower(n[:len(p)]) == p {
-			n = n[len(p):]
-			host += p
+	consumeHostStrings := func(parts []string) {
+		for _, p := range parts {
+			if len(p) < len(n) && strings.ToLower(n[:len(p)]) == p {
+				n = n[len(p):]
+				host += p
+			}
 		}
 	}
+	// Start accumulating the host part.
+	// Order matters here.
+	consumeHostStrings([]string{"git::", "gh:", "ssh://", "https://", "http://"})
+	if p := userRegex.FindString(n); p != "" {
+		n = n[len(p):]
+		host += p
+	}
+	consumeHostStrings([]string{"github.com:", "github.com/"})
 	if host == "git@" {
 		i := strings.Index(n, "/")
 		if i > -1 {
@@ -241,7 +250,9 @@ func parseHostSpec(n string) (string, string) {
 func normalizeGitHostSpec(host string) string {
 	s := strings.ToLower(host)
 	if strings.Contains(s, "github.com") {
-		if strings.Contains(s, "git@") || strings.Contains(s, "ssh:") {
+		if m := userRegex.FindString(host); m != "" {
+			host = m + "github.com:"
+		} else if strings.Contains(s, "ssh:") {
 			host = "git@github.com:"
 		} else {
 			host = "https://github.com/"

api/internal/git/repospec_test.go

@@ -35,6 +35,8 @@ var hostNamesRawAndNormalized = [][]string{
 	{"git::https://git.example.com/", "https://git.example.com/"},
 	{"git@github.com:", "git@github.com:"},
 	{"git@github.com/", "git@github.com:"},
+	{"org-12345@github.com:", "org-12345@github.com:"},
+	{"org-12345@github.com/", "org-12345@github.com:"},
 }
 
 func makeURL(hostFmt, orgRepo, path, href string) string {
@@ -60,6 +62,9 @@ func TestNewRepoSpecFromUrl(t *testing.T) {
 					rs, err := NewRepoSpecFromURL(uri)
 					if err != nil {
 						t.Errorf("problem %v", err)
+						if rs == nil {
+							rs = &RepoSpec{}
+						}
 					}
 					if rs.Host != hostSpec {
 						bad = append(bad, []string{"host", uri, rs.Host, hostSpec})