Meaningful error propagation when config not found

viper.go

@@ -694,33 +694,42 @@ 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")
-	if !stringInSlice(v.getConfigType(), SupportedExts) {
-		return UnsupportedConfigError(v.getConfigType())
+
+	cfgType, err := v.getConfigType()
+	if err != nil {
+		return err
 	}
 
-	file, err := ioutil.ReadFile(v.getConfigFile())
+	if !stringInSlice(cfgType, SupportedExts) {
+		return UnsupportedConfigError(cfgType)
+	}
+
+	fname, err := v.getConfigFile()
+	if err != nil {
+		return err
+	}
+
+	file, err := ioutil.ReadFile(fname)
 	if err != nil {
 		return err
 	}
 
 	v.config = make(map[string]interface{})
 
-	v.marshalReader(bytes.NewReader(file), v.config)
-	return nil
+	return v.marshalReader(bytes.NewReader(file), v.config)
 }
 
 func ReadConfig(in io.Reader) error { return v.ReadConfig(in) }
+
 func (v *Viper) ReadConfig(in io.Reader) error {
 	v.config = make(map[string]interface{})
-	v.marshalReader(in, v.config)
-	return nil
+	return v.marshalReader(in, v.config)
 }
 
 // func ReadBufConfig(buf *bytes.Buffer) error { return v.ReadBufConfig(buf) }
 // func (v *Viper) ReadBufConfig(buf *bytes.Buffer) error {
 // 	v.config = make(map[string]interface{})
-// 	v.marshalReader(buf, v.config)
-// 	return nil
+// 	return v.marshalReader(buf, v.config)
 // }
 
 // Attempts to get configuration from a remote source
@@ -745,9 +754,17 @@ func (v *Viper) WatchRemoteConfig() error {
 
 // Marshall a Reader into a map
 // Should probably be an unexported function
-func marshalReader(in io.Reader, c map[string]interface{}) { v.marshalReader(in, c) }
-func (v *Viper) marshalReader(in io.Reader, c map[string]interface{}) {
-	marshallConfigReader(in, c, v.getConfigType())
+func marshalReader(in io.Reader, c map[string]interface{}) error {
+	return v.marshalReader(in, c)
+}
+
+func (v *Viper) marshalReader(in io.Reader, c map[string]interface{}) error {
+	cfgType, err := v.getConfigType()
+	if err != nil {
+		return err
+	}
+	marshallConfigReader(in, c, cfgType)
+	return nil
 }
 
 func (v *Viper) insensitiviseMaps() {
@@ -800,7 +817,7 @@ func (v *Viper) getRemoteConfig(provider *remoteProvider) (map[string]interface{
 		return nil, err
 	}
 	reader := bytes.NewReader(b)
-	v.marshalReader(reader, v.kvstore)
+	err = v.marshalReader(reader, v.kvstore)
 	return v.kvstore, err
 }
 
@@ -850,7 +867,7 @@ func (v *Viper) watchRemoteConfig(provider *remoteProvider) (map[string]interfac
 	}
 
 	reader := bytes.NewReader(resp.Value)
-	v.marshalReader(reader, v.kvstore)
+	err = v.marshalReader(reader, v.kvstore)
 	return v.kvstore, err
 }
 
@@ -912,34 +929,35 @@ func (v *Viper) SetConfigType(in string) {
 	}
 }
 
-func (v *Viper) getConfigType() string {
+func (v *Viper) getConfigType() (string, error) {
 	if v.configType != "" {
-		return v.configType
+		return v.configType, nil
+	}
+
+	cf, err := v.getConfigFile()
+	if err != nil {
+		return "", err
 	}
 
-	cf := v.getConfigFile()
 	ext := filepath.Ext(cf)
 
 	if len(ext) > 1 {
-		return ext[1:]
+		return ext[1:], nil
 	} else {
-		return ""
+		return "", fmt.Errorf("Missing config file extension in %q", cf)
 	}
 }
 
-func (v *Viper) getConfigFile() string {
+func (v *Viper) getConfigFile() (string, error) {
+	var err 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 ""
-	}
-
-	v.configFile = cf
-	return v.getConfigFile()
+	v.configFile, err = v.findConfigFile()
+	return v.configFile, err
 }
 
 func (v *Viper) searchInPath(in string) (filename string) {
@@ -958,11 +976,13 @@ func (v *Viper) searchInPath(in string) (filename string) {
 // Choose where to look for a config file: either
 // in provided directories or in the working directory
 func (v *Viper) findConfigFile() (string, error) {
+
 	if len(v.configPaths) > 0 {
 		return v.findConfigInPaths()
 	} else {
 		return v.findConfigInWD()
 	}
+
 }
 
 // Search all configPaths for any config file.

viper_test.go

@@ -147,7 +147,9 @@ func (s *stringValue) String() string {
 
 func TestBasics(t *testing.T) {
 	SetConfigFile("/tmp/config.yaml")
-	assert.Equal(t, "/tmp/config.yaml", v.getConfigFile())
+	cf, err := v.getConfigFile()
+	assert.Equal(t, nil, err)
+	assert.Equal(t, "/tmp/config.yaml", cf)
 }
 
 func TestDefault(t *testing.T) {