Use example config for default values

config/bridge.go

@@ -17,6 +17,7 @@
 package config
 
 import (
+	"fmt"
 	"strconv"
 	"strings"
 	"text/template"
@@ -97,29 +98,6 @@ type BridgeConfig struct {
 	displaynameTemplate *template.Template `yaml:"-"`
 }
 
-func (bc *BridgeConfig) setDefaults() {
-	bc.PortalMessageBuffer = 128
-
-	bc.CallNotices.Start = true
-	bc.CallNotices.End = true
-
-	bc.HistorySync.CreatePortals = true
-	bc.HistorySync.MaxAge = 604800
-	bc.UserAvatarSync = true
-	bc.BridgeMatrixLeave = true
-
-	bc.SyncWithCustomPuppets = true
-	bc.DefaultBridgePresence = true
-	bc.DefaultBridgeReceipts = true
-
-	bc.BridgeNotices = true
-	bc.EnableStatusBroadcast = true
-
-	bc.ManagementRoomText.Welcome = "Hello, I'm a WhatsApp bridge bot."
-	bc.ManagementRoomText.WelcomeConnected = "Use `help` for help."
-	bc.ManagementRoomText.WelcomeUnconnected = "Use `help` for help or `login` to log in."
-}
-
 type umBridgeConfig BridgeConfig
 
 func (bc *BridgeConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
@@ -131,6 +109,8 @@ func (bc *BridgeConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	bc.usernameTemplate, err = template.New("username").Parse(bc.UsernameTemplate)
 	if err != nil {
 		return err
+	} else if !strings.Contains(bc.FormatUsername("1234567890"), "1234567890") {
+		return fmt.Errorf("username template is missing user ID placeholder")
 	}
 
 	bc.displaynameTemplate, err = template.New("displayname").Parse(bc.DisplaynameTemplate)

config/config.go

@@ -17,6 +17,7 @@
 package config
 
 import (
+	"fmt"
 	"io/ioutil"
 
 	"gopkg.in/yaml.v2"
@@ -25,6 +26,8 @@ import (
 	"maunium.net/go/mautrix/appservice"
 )
 
+var ExampleConfig string
+
 type Config struct {
 	Homeserver struct {
 		Address        string `yaml:"address"`
@@ -88,14 +91,6 @@ func (config *Config) CanDoublePuppet(userID id.UserID) bool {
 	return true
 }
 
-func (config *Config) setDefaults() {
-	config.AppService.Database.MaxOpenConns = 20
-	config.AppService.Database.MaxIdleConns = 2
-	config.WhatsApp.OSName = "Mautrix-WhatsApp bridge"
-	config.WhatsApp.BrowserName = "mx-wa"
-	config.Bridge.setDefaults()
-}
-
 func Load(path string) (*Config, error) {
 	data, err := ioutil.ReadFile(path)
 	if err != nil {
@@ -103,7 +98,10 @@ func Load(path string) (*Config, error) {
 	}
 
 	var config = &Config{}
-	config.setDefaults()
+	err = yaml.UnmarshalStrict([]byte(ExampleConfig), config)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshal example config: %w", err)
+	}
 	err = yaml.Unmarshal(data, config)
 	return config, err
 }

main.go

@@ -26,6 +26,7 @@ import (
 	"sync"
 	"syscall"
 	"time"
+	_ "embed"
 
 	"google.golang.org/protobuf/proto"
 
@@ -70,6 +71,9 @@ var (
 	VersionString = ""
 )
 
+//go:embed example-config.yaml
+var ExampleConfig string
+
 func init() {
 	if len(Tag) > 0 && Tag[0] == 'v' {
 		Tag = Tag[1:]
@@ -88,6 +92,8 @@ func init() {
 	mautrix.DefaultUserAgent = fmt.Sprintf("mautrix-whatsapp/%s %s", Version, mautrix.DefaultUserAgent)
 	WAVersion = strings.FieldsFunc(Version, func(r rune) bool { return r == '-' || r == '+' })[0]
 	VersionString = fmt.Sprintf("%s %s (%s)", Name, Version, BuildTime)
+
+	config.ExampleConfig = ExampleConfig
 }
 
 var configPath = flag.MakeFull("c", "config", "The path to your config file.", "config.yaml").String()