add test helper for config yaml tags (#2791)

* add test helper for config yaml tags

* deps

* cleanup

* cleanup

go.mod

@@ -20,7 +20,7 @@ require (
 	github.com/jxskiss/base62 v1.1.0
 	github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1
 	github.com/livekit/mediatransportutil v0.0.0-20240613015318-84b69facfb75
-	github.com/livekit/protocol v1.17.1-0.20240614054716-725bc923f98b
+	github.com/livekit/protocol v1.17.1-0.20240614060801-425cb974f7a4
 	github.com/livekit/psrpc v0.5.3-0.20240526192918-fbdaf10e6aa5
 	github.com/mackerelio/go-osstat v0.2.5
 	github.com/magefile/mage v1.15.0
@@ -48,6 +48,7 @@ require (
 	github.com/urfave/cli/v2 v2.27.2
 	github.com/urfave/negroni/v3 v3.1.1
 	go.uber.org/atomic v1.11.0
+	go.uber.org/multierr v1.11.0
 	go.uber.org/zap v1.27.0
 	golang.org/x/exp v0.0.0-20240604190554-fc45aab8b7f8
 	golang.org/x/sync v0.7.0
@@ -97,7 +98,6 @@ require (
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/xrash/smetrics v0.0.0-20240312152122-5f08fbb34913 // indirect
 	github.com/zeebo/xxh3 v1.0.2 // indirect
-	go.uber.org/multierr v1.11.0 // indirect
 	go.uber.org/zap/exp v0.2.0 // indirect
 	golang.org/x/crypto v0.24.0 // indirect
 	golang.org/x/mod v0.18.0 // indirect

go.sum

@@ -120,8 +120,8 @@ github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1 h1:jm09419p0lqTkD
 github.com/livekit/mageutil v0.0.0-20230125210925-54e8a70427c1/go.mod h1:Rs3MhFwutWhGwmY1VQsygw28z5bWcnEYmS1OG9OxjOQ=
 github.com/livekit/mediatransportutil v0.0.0-20240613015318-84b69facfb75 h1:p60OjeixzXnhGFQL8wmdUwWPxijEDe9ZJFMosq+byec=
 github.com/livekit/mediatransportutil v0.0.0-20240613015318-84b69facfb75/go.mod h1:jwKUCmObuiEDH0iiuJHaGMXwRs3RjrB4G6qqgkr/5oE=
-github.com/livekit/protocol v1.17.1-0.20240614054716-725bc923f98b h1:wRADQpZkCv2ml1W3PZCmFxJKdyAS4T1nleaAdv8rRpY=
-github.com/livekit/protocol v1.17.1-0.20240614054716-725bc923f98b/go.mod h1:cN8WmGQR+kWz1+UWcAQdFFUcbW76PnfZDdkLAbYIqd4=
+github.com/livekit/protocol v1.17.1-0.20240614060801-425cb974f7a4 h1:5O3/wahQIMnw+PO3O1kgxPSrpJf7PkPcD3GvWmb1TJQ=
+github.com/livekit/protocol v1.17.1-0.20240614060801-425cb974f7a4/go.mod h1:cN8WmGQR+kWz1+UWcAQdFFUcbW76PnfZDdkLAbYIqd4=
 github.com/livekit/psrpc v0.5.3-0.20240526192918-fbdaf10e6aa5 h1:mTZyrjk5WEWMsvaYtJ42pG7DuxysKj21DKPINpGSIto=
 github.com/livekit/psrpc v0.5.3-0.20240526192918-fbdaf10e6aa5/go.mod h1:CQUBSPfYYAaevg1TNCc6/aYsa8DJH4jSRFdCeSZk5u0=
 github.com/mackerelio/go-osstat v0.2.5 h1:+MqTbZUhoIt4m8qzkVoXUJg1EuifwlAJSk4Yl2GXh+o=

pkg/config/config_test.go

@@ -20,6 +20,8 @@ import (
 
 	"github.com/stretchr/testify/require"
 	"github.com/urfave/cli/v2"
+
+	"github.com/livekit/livekit-server/pkg/config/configtest"
 )
 
 func TestConfig_UnmarshalKeys(t *testing.T) {
@@ -80,3 +82,7 @@ func TestGeneratedFlags(t *testing.T) {
 	require.NotNil(t, conf.RTC.ReconnectOnSubscriptionError)
 	require.False(t, *conf.RTC.ReconnectOnSubscriptionError)
 }
+
+func TestYAMLTag(t *testing.T) {
+	require.NoError(t, configtest.CheckYAMLTags(Config{}))
+}

pkg/config/configtest/checkyamltag.go

@@ -0,0 +1,64 @@
+package configtest
+
+import (
+	"fmt"
+	"reflect"
+	"slices"
+	"strings"
+
+	"go.uber.org/multierr"
+	"google.golang.org/protobuf/proto"
+)
+
+var protoMessageType = reflect.TypeOf((*proto.Message)(nil)).Elem()
+
+func checkYAMLTags(t reflect.Type, seen map[reflect.Type]struct{}) error {
+	if _, ok := seen[t]; ok {
+		return nil
+	}
+	seen[t] = struct{}{}
+
+	switch t.Kind() {
+	case reflect.Array, reflect.Map, reflect.Slice, reflect.Pointer:
+		return checkYAMLTags(t.Elem(), seen)
+	case reflect.Struct:
+		if reflect.PointerTo(t).Implements(protoMessageType) {
+			// ignore protobuf messages
+			return nil
+		}
+
+		var errs error
+		for i := 0; i < t.NumField(); i++ {
+			field := t.Field(i)
+
+			if field.Type.Kind() == reflect.Bool {
+				// ignore boolean fields
+				continue
+			}
+
+			if field.Tag.Get("config") == "allowempty" {
+				// ignore configured exceptions
+				continue
+			}
+
+			parts := strings.Split(field.Tag.Get("yaml"), ",")
+			if parts[0] == "-" {
+				// ignore unparsed fields
+				continue
+			}
+
+			if !slices.Contains(parts, "omitempty") && !slices.Contains(parts, "inline") {
+				errs = multierr.Append(errs, fmt.Errorf("%s/%s.%s missing omitempty tag", t.PkgPath(), t.Name(), field.Name))
+			}
+
+			errs = multierr.Append(errs, checkYAMLTags(field.Type, seen))
+		}
+		return errs
+	default:
+		return nil
+	}
+}
+
+func CheckYAMLTags(config any) error {
+	return checkYAMLTags(reflect.TypeOf(config), map[reflect.Type]struct{}{})
+}