Allow errors to propagate from getConfigFile(). (#161)

- propagate ConfigFileNotFoundError instead of using unsupported config type error when config file is not found

viper.go

@@ -241,7 +241,13 @@ func (v *Viper) WatchConfig() {
 		defer watcher.Close()
 
 		// we have to watch the entire directory to pick up renames/atomic saves in a cross-platform way
-		configFile := filepath.Clean(v.getConfigFile())
+		filename, err := v.getConfigFile()
+		if err != nil {
+			log.Println("error:", err)
+			return
+		}
+
+		configFile := filepath.Clean(filename)
 		configDir, _ := filepath.Split(configFile)
 
 		done := make(chan bool)
@@ -1102,11 +1108,16 @@ func (v *Viper) Set(key string, value interface{}) {
 func ReadInConfig() error { return v.ReadInConfig() }
 func (v *Viper) ReadInConfig() error {
 	jww.INFO.Println("Attempting to read in config file")
+	filename, err := v.getConfigFile()
+	if err != nil {
+		return err
+	}
+
 	if !stringInSlice(v.getConfigType(), SupportedExts) {
 		return UnsupportedConfigError(v.getConfigType())
 	}
 
-	file, err := afero.ReadFile(v.fs, v.getConfigFile())
+	file, err := afero.ReadFile(v.fs, filename)
 	if err != nil {
 		return err
 	}
@@ -1124,7 +1135,12 @@ func (v *Viper) MergeInConfig() error {
 		return UnsupportedConfigError(v.getConfigType())
 	}
 
-	file, err := afero.ReadFile(v.fs, v.getConfigFile())
+	filename, err := v.getConfigFile()
+	if err != nil {
+		return err
+	}
+
+	file, err := afero.ReadFile(v.fs, filename)
 	if err != nil {
 		return err
 	}
@@ -1460,7 +1476,11 @@ func (v *Viper) getConfigType() string {
 		return v.configType
 	}
 
-	cf := v.getConfigFile()
+	cf, err := v.getConfigFile()
+	if err != nil {
+		return ""
+	}
+
 	ext := filepath.Ext(cf)
 
 	if len(ext) > 1 {
@@ -1470,15 +1490,15 @@ func (v *Viper) getConfigType() string {
 	return ""
 }
 
-func (v *Viper) getConfigFile() string {
+func (v *Viper) getConfigFile() (string, error) {
 	// if explicitly set, then use it
 	if v.configFile != "" {
-		return v.configFile
+		return v.configFile, nil
 	}
 
 	cf, err := v.findConfigFile()
 	if err != nil {
-		return ""
+		return "", err
 	}
 
 	v.configFile = cf

viper_test.go

@@ -243,7 +243,9 @@ func (s *stringValue) String() string {
 
 func TestBasics(t *testing.T) {
 	SetConfigFile("/tmp/config.yaml")
-	assert.Equal(t, "/tmp/config.yaml", v.getConfigFile())
+	filename, err := v.getConfigFile()
+	assert.Equal(t, "/tmp/config.yaml", filename)
+	assert.NoError(t, err)
 }
 
 func TestDefault(t *testing.T) {
@@ -745,7 +747,7 @@ func TestWrongDirsSearchNotFound(t *testing.T) {
 	v.AddConfigPath(`thispathaintthere`)
 
 	err := v.ReadInConfig()
-	assert.Equal(t, reflect.TypeOf(UnsupportedConfigError("")), reflect.TypeOf(err))
+	assert.Equal(t, reflect.TypeOf(ConfigFileNotFoundError{"", ""}), reflect.TypeOf(err))
 
 	// Even though config did not load and the error might have
 	// been ignored by the client, the default still loads
@@ -915,7 +917,11 @@ func TestUnmarshalingWithAliases(t *testing.T) {
 func TestSetConfigNameClearsFileCache(t *testing.T) {
 	SetConfigFile("/tmp/config.yaml")
 	SetConfigName("default")
-	assert.Empty(t, v.getConfigFile())
+	f, err := v.getConfigFile()
+	if err == nil {
+		t.Fatalf("config file cache should have been cleared")
+	}
+	assert.Empty(t, f)
 }
 
 func TestShadowedNestedValue(t *testing.T) {