Report configuration persistence failures

config/user_config.go

@@ -58,6 +58,9 @@ func (c *Config) SaveConfig() error {
 }
 
 func (c *Config) saveConfigLocked() error {
+	if err := os.MkdirAll(filepath.Dir(c.fn), 0700); err != nil {
+		return err
+	}
 	data, err := toml.Marshal(c.config)
 	if err != nil {
 		return err
@@ -286,13 +289,13 @@ func (c *Config) findUser(address string, username string) *eUser {
 	return t
 }
 
-func (c *Config) ToggleMute(u *gumble.User) {
+func (c *Config) ToggleMute(u *gumble.User) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	j := c.findUser(u.GetClient().Config.Address, u.Name)
 	j.LocallyMuted = !j.LocallyMuted
 	u.SetLocallyMuted(j.LocallyMuted)
-	_ = c.saveConfigLocked()
+	return c.saveConfigLocked()
 }
 
 func (c *Config) SetMicVolume(v float32) {
@@ -355,11 +358,11 @@ func (c *Config) GetNoiseSuppressionEnabled() bool {
 	return *c.config.NoiseSuppressionEnabled
 }
 
-func (c *Config) SetNoiseSuppressionEnabled(enabled bool) {
+func (c *Config) SetNoiseSuppressionEnabled(enabled bool) error {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	c.config.NoiseSuppressionEnabled = &enabled
-	_ = c.saveConfigLocked()
+	return c.saveConfigLocked()
 }
 
 func (c *Config) GetRecordingFormat() string {

config/user_config_save_test.go

@@ -7,13 +7,19 @@ import (
 	"testing"
 )
 
-// Regression: a configuration write failure panicked the client instead of
-// returning an error to the caller.
-func TestSaveConfigReturnsWriteError(t *testing.T) {
-	path := filepath.Join(t.TempDir(), "missing", "barnard.toml")
+func TestSaveConfigCreatesMissingParentDirectory(t *testing.T) {
+	parent := filepath.Join(t.TempDir(), "missing")
+	path := filepath.Join(parent, "barnard.toml")
 	cfg := NewConfig(&path)
-	if err := cfg.SaveConfig(); err == nil {
-		t.Fatal("expected configuration write error")
+	if err := cfg.SaveConfig(); err != nil {
+		t.Fatal(err)
+	}
+	info, err := os.Stat(parent)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if info.Mode().Perm()&0077 != 0 {
+		t.Fatalf("parent directory permissions = %o, want no group or other access", info.Mode().Perm())
 	}
 }