ci: enable unparam linter

And fix the last warning from it:

match.go:31:20: `withMatchType` - `typ` always receives `"signal"` (unparam)
func withMatchType(typ string) MatchOption {
                   ^

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

.golangci.yml

@@ -4,3 +4,4 @@ linters:
   enable:
     - gofumpt
     - unconvert
+    - unparam

conn.go

@@ -629,7 +629,7 @@ func (conn *Conn) AddMatchSignal(options ...MatchOption) error {
 
 // AddMatchSignalContext acts like AddMatchSignal but takes a context.
 func (conn *Conn) AddMatchSignalContext(ctx context.Context, options ...MatchOption) error {
-	options = append([]MatchOption{withMatchType("signal")}, options...)
+	options = append([]MatchOption{withMatchTypeSignal()}, options...)
 	return conn.busObj.CallWithContext(
 		ctx,
 		"org.freedesktop.DBus.AddMatch", 0,
@@ -644,7 +644,7 @@ func (conn *Conn) RemoveMatchSignal(options ...MatchOption) error {
 
 // RemoveMatchSignalContext acts like RemoveMatchSignal but takes a context.
 func (conn *Conn) RemoveMatchSignalContext(ctx context.Context, options ...MatchOption) error {
-	options = append([]MatchOption{withMatchType("signal")}, options...)
+	options = append([]MatchOption{withMatchTypeSignal()}, options...)
 	return conn.busObj.CallWithContext(
 		ctx,
 		"org.freedesktop.DBus.RemoveMatch", 0,

match.go

@@ -26,10 +26,10 @@ func WithMatchOption(key, value string) MatchOption {
 	return MatchOption{key, value}
 }
 
-// doesn't make sense to export this option because clients can only
-// subscribe to messages with signal type.
-func withMatchType(typ string) MatchOption {
-	return WithMatchOption("type", typ)
+// It does not make sense to have a public WithMatchType function
+// because clients can only subscribe to messages with signal type.
+func withMatchTypeSignal() MatchOption {
+	return WithMatchOption("type", "signal")
 }
 
 // WithMatchSender sets sender match option.

match_test.go

@@ -4,7 +4,7 @@ import "testing"
 
 func TestFormatMatchOptions(t *testing.T) {
 	opts := []MatchOption{
-		withMatchType("signal"),
+		withMatchTypeSignal(),
 		WithMatchSender("org.bluez"),
 		WithMatchInterface("org.freedesktop.DBus.Properties"),
 		WithMatchMember("PropertiesChanged"),

object.go

@@ -46,7 +46,7 @@ func (o *Object) CallWithContext(ctx context.Context, method string, flags Flags
 // Deprecated: use (*Conn) AddMatchSignal instead.
 func (o *Object) AddMatchSignal(iface, member string, options ...MatchOption) *Call {
 	base := []MatchOption{
-		withMatchType("signal"),
+		withMatchTypeSignal(),
 		WithMatchInterface(iface),
 		WithMatchMember(member),
 	}
@@ -65,7 +65,7 @@ func (o *Object) AddMatchSignal(iface, member string, options ...MatchOption) *C
 // Deprecated: use (*Conn) RemoveMatchSignal instead.
 func (o *Object) RemoveMatchSignal(iface, member string, options ...MatchOption) *Call {
 	base := []MatchOption{
-		withMatchType("signal"),
+		withMatchTypeSignal(),
 		WithMatchInterface(iface),
 		WithMatchMember(member),
 	}