add new API to return canonical target String

Author: arvindbr8

clientconn.go

@@ -893,6 +893,16 @@ func (cc *ClientConn) Target() string {
 	return cc.target
 }
 
+// CanonicalTarget returns the canonical target string of the ClientConn.
+//
+// # Experimental
+//
+// Notice: This API is EXPERIMENTAL and may be changed or removed in a later
+// release.
+func (cc *ClientConn) CanonicalTarget() string {
+	return cc.parsedTarget.String()
+}
+
 func (cc *ClientConn) incrCallsStarted() {
 	atomic.AddInt64(&cc.czData.callsStarted, 1)
 	atomic.StoreInt64(&cc.czData.lastCallStartedTime, time.Now().UnixNano())

clientconn_test.go

@@ -808,15 +808,47 @@ func (s) TestMethodConfigDefaultService(t *testing.T) {
 	}
 }
 
-func (s) TestGetClientConnTarget(t *testing.T) {
-	addr := "nonexist:///non.existent"
-	cc, err := Dial(addr, WithTransportCredentials(insecure.NewCredentials()))
-	if err != nil {
-		t.Fatalf("Dial(%s, _) = _, %v, want _, <nil>", addr, err)
+func (s) TestClientConnCanonicalTarget(t *testing.T) {
+	tests := []struct {
+		name                string
+		addr                string
+		canonicalTargetWant string
+	}{
+		{
+			name:                "normal-case",
+			addr:                "dns://a.server.com/google.com",
+			canonicalTargetWant: "dns://a.server.com/google.com",
+		},
+		{
+			name:                "canonical-target-not-specified",
+			addr:                "no.scheme",
+			canonicalTargetWant: "passthrough:///no.scheme",
+		},
+		{
+			name:                "canonical-target-nonexistent",
+			addr:                "nonexist:///non.existent",
+			canonicalTargetWant: "passthrough:///nonexist:///non.existent",
+		},
+		{
+			name:                "canonical-target-add-colon-slash",
+			addr:                "dns:hostname:port",
+			canonicalTargetWant: "dns:///hostname:port",
+		},
 	}
-	defer cc.Close()
-	if cc.Target() != addr {
-		t.Fatalf("Target() = %s, want %s", cc.Target(), addr)
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			cc, err := Dial(test.addr, WithTransportCredentials(insecure.NewCredentials()))
+			if err != nil {
+				t.Fatalf("Dial(%s, _) = _, %v, want _, <nil>", test.addr, err)
+			}
+			defer cc.Close()
+			if cc.Target() != test.addr {
+				t.Fatalf("Target() = %s, want %s", cc.Target(), test.addr)
+			}
+			if cc.CanonicalTarget() != test.canonicalTargetWant {
+				t.Fatalf("CanonicalTarget() = %s, want %s", cc.CanonicalTarget(), test.canonicalTargetWant)
+			}
+		})
 	}
 }
 

resolver/resolver.go

@@ -281,9 +281,9 @@ func (t Target) Endpoint() string {
 	return strings.TrimPrefix(endpoint, "/")
 }
 
-// String returns a string representation of Target.
+// String returns the canonical string representation of Target.
 func (t Target) String() string {
-	return t.URL.String()
+	return t.URL.Scheme + "://" + t.URL.Host + "/" + t.Endpoint()
 }
 
 // Builder creates a resolver that will be used to watch name resolution updates.