review comments

- strip the leading "/" unconditionally in parseTarget()
- do not strip the leading "/" from endpoint in DialContext() since this
  is done in parseTarget()
- move the resolver building to inside the if in
  parseTargetAndFindResolver()
- doc comments in resolver.go

clientconn.go

@@ -259,7 +259,7 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *
 	// scheme and empty hostname (":port").
 	// TODO: Define an optional interface on the resolver builder to return the
 	// authority given the user's dial target.
-	cc.authority = strings.TrimPrefix(cc.parsedTarget.Endpoint, "/")
+	cc.authority = cc.parsedTarget.Endpoint
 	if strings.HasPrefix(cc.authority, ":") {
 		cc.authority = "localhost" + cc.authority
 	}
@@ -1630,16 +1630,18 @@ func (cc *ClientConn) connectionError() error {
 
 func (cc *ClientConn) parseTargetAndFindResolver() (resolver.Builder, error) {
 	channelz.Infof(logger, cc.channelzID, "original dial target is: %q", cc.target)
+
+	var rb resolver.Builder
 	parsedTarget, err := parseTarget(cc.target)
 	if err != nil {
 		channelz.Infof(logger, cc.channelzID, "dial target %q parse failed: %v", cc.target, err)
 	} else {
 		channelz.Infof(logger, cc.channelzID, "parsed dial target is: %+v", parsedTarget)
-	}
-	rb := cc.getResolver(parsedTarget.Scheme)
-	if rb != nil {
-		cc.parsedTarget = parsedTarget
-		return rb, nil
+		rb = cc.getResolver(parsedTarget.Scheme)
+		if rb != nil {
+			cc.parsedTarget = parsedTarget
+			return rb, nil
+		}
 	}
 
 	// We are here because the user's dial target did not contain a scheme or
@@ -1687,9 +1689,7 @@ func parseTarget(target string) (resolver.Target, error) {
 	if endpoint == "" {
 		endpoint = u.Opaque
 	}
-	if strings.HasPrefix(target, fmt.Sprintf("%s://", u.Scheme)) {
-		endpoint = strings.TrimPrefix(endpoint, "/")
-	}
+	endpoint = strings.TrimPrefix(endpoint, "/")
 	return resolver.Target{
 		Scheme:    u.Scheme,
 		Authority: u.Host,

clientconn_parsed_target_test.go

@@ -69,15 +69,15 @@ func (s) TestParsedTarget_Success_WithoutCustomDialer(t *testing.T) {
 		{target: "unix-abstract:a b", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: "a b"}},
 		{target: "unix-abstract:a:b", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: "a:b"}},
 		{target: "unix-abstract:a-b", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: "a-b"}},
-		{target: "unix-abstract:/ a///://::!@#$%25^&*()b", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: "/ a///://::!@"}},
+		{target: "unix-abstract:/ a///://::!@#$%25^&*()b", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: " a///://::!@"}},
 		{target: "unix-abstract:passthrough:abc", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: "passthrough:abc"}},
 		{target: "unix-abstract:unix:///abc", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: "unix:///abc"}},
 		{target: "unix-abstract:///a/b/c", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: "a/b/c"}},
 		{target: "unix-abstract:///", wantParsed: resolver.Target{Scheme: "unix-abstract", Authority: "", Endpoint: ""}},
 		{target: "passthrough:///unix:///a/b/c", wantParsed: resolver.Target{Scheme: "passthrough", Authority: "", Endpoint: "unix:///a/b/c"}},
 
 		// Cases for `scheme:absolute-path`.
-		{target: "dns:/a/b/c", wantParsed: resolver.Target{Scheme: "dns", Authority: "", Endpoint: "/a/b/c"}},
+		{target: "dns:/a/b/c", wantParsed: resolver.Target{Scheme: "dns", Authority: "", Endpoint: "a/b/c"}},
 		{target: "unregistered:/a/b/c", wantParsed: resolver.Target{Scheme: defScheme, Authority: "", Endpoint: "unregistered:/a/b/c"}},
 	}
 
@@ -130,7 +130,7 @@ func (s) TestParsedTarget_WithCustomDialer(t *testing.T) {
 		},
 		{
 			target:            "unix:/a/b/c",
-			wantParsed:        resolver.Target{Scheme: "unix", Authority: "", Endpoint: "/a/b/c"},
+			wantParsed:        resolver.Target{Scheme: "unix", Authority: "", Endpoint: "a/b/c"},
 			wantDialerAddress: "unix:///a/b/c",
 		},
 		{

resolver/resolver.go

@@ -217,11 +217,11 @@ type ClientConn interface {
 // Examples:
 //
 // - "dns://some_authority/foo.bar"
-//   Target{Scheme: "dns", Authority: "some_authority", Endpoint: "/foo.bar"}
+//   Target{Scheme: "dns", Authority: "some_authority", Endpoint: "foo.bar"}
 // - "foo.bar"
-//   Target{Scheme: resolver.GetDefaultScheme(), Endpoint: "/foo.bar"}
+//   Target{Scheme: resolver.GetDefaultScheme(), Endpoint: "foo.bar"}
 // - "unknown_scheme://authority/endpoint"
-//   Target{Scheme: resolver.GetDefaultScheme(), Endpoint: "/unknown_scheme://authority/endpoint"}
+//   Target{Scheme: resolver.GetDefaultScheme(), Endpoint: "unknown_scheme://authority/endpoint"}
 type Target struct {
 	Scheme    string
 	Authority string