Fix parseTarget for unix socket address without scheme (#1611)

resolver_conn_wrapper_test.go

@@ -34,14 +34,46 @@ func TestParseTarget(t *testing.T) {
 		{"a", "", "b"},
 		{"", "a", "b"},
 		{"a", "b", "c"},
-		{"dns", "a.server.com", "google.com"},
+		{"dns", "", "google.com"},
 		{"dns", "a.server.com", "google.com"},
 		{"dns", "a.server.com", "google.com/?a=b"},
+		{"", "", "/unix/socket/address"},
 	} {
 		str := test.Scheme + "://" + test.Authority + "/" + test.Endpoint
 		got := parseTarget(str)
 		if got != test {
-			t.Errorf("parseTarget(%q) = %v, want %v", str, got, test)
+			t.Errorf("parseTarget(%q) = %+v, want %+v", str, got, test)
+		}
+	}
+}
+
+func TestParseTargetString(t *testing.T) {
+	for _, test := range []struct {
+		targetStr string
+		want      resolver.Target
+	}{
+		{"", resolver.Target{"", "", ""}},
+		{"://", resolver.Target{"", "", ""}},
+		{":///", resolver.Target{"", "", ""}},
+		{"a:///", resolver.Target{"a", "", ""}},
+		{"://a/", resolver.Target{"", "a", ""}},
+		{":///a", resolver.Target{"", "", "a"}},
+		{"a://b/", resolver.Target{"a", "b", ""}},
+		{"a:///b", resolver.Target{"a", "", "b"}},
+		{"://a/b", resolver.Target{"", "a", "b"}},
+		{"a://b/c", resolver.Target{"a", "b", "c"}},
+		{"dns:///google.com", resolver.Target{"dns", "", "google.com"}},
+		{"dns://a.server.com/google.com", resolver.Target{"dns", "a.server.com", "google.com"}},
+		{"dns://a.server.com/google.com/?a=b", resolver.Target{"dns", "a.server.com", "google.com/?a=b"}},
+
+		{"/", resolver.Target{"", "", "/"}},
+		{"google.com", resolver.Target{"", "", "google.com"}},
+		{"google.com/?a=b", resolver.Target{"", "", "google.com/?a=b"}},
+		{"/unix/socket/address", resolver.Target{"", "", "/unix/socket/address"}},
+	} {
+		got := parseTarget(test.targetStr)
+		if got != test.want {
+			t.Errorf("parseTarget(%q) = %+v, want %+v", test.targetStr, got, test.want)
 		}
 	}
 }