skip name (#85)

Signed-off-by: Oleg Kovalov <[email protected]>

aconfig.go

@@ -154,6 +154,9 @@ func (l *Loader) init() {
 	if !l.config.SkipFlags {
 		for _, field := range l.fields {
 			flagName := l.fullTag(l.config.FlagPrefix, field, flagNameTag)
+			if flagName == "" {
+				continue
+			}
 			l.flagSet.String(flagName, field.Tag(defaultValueTag), field.Tag(usageTag))
 		}
 	}
@@ -298,6 +301,9 @@ func (l *Loader) loadFile(file string) error {
 
 	for _, field := range l.fields {
 		name := l.fullTag("", field, tag)
+		if name == "" {
+			continue
+		}
 		value, ok := actualFields[name]
 		if !ok {
 			actualFields = find(actualFields, name)
@@ -346,6 +352,9 @@ func (l *Loader) loadEnvironment() error {
 
 	for _, field := range l.fields {
 		envName := l.fullTag(l.config.EnvPrefix, field, envNameTag)
+		if envName == "" {
+			continue
+		}
 
 		if err := l.setField(field, envName, actualEnvs); err != nil {
 			return err
@@ -367,6 +376,9 @@ func (l *Loader) loadFlags() error {
 
 	for _, field := range l.fields {
 		flagName := l.fullTag(l.config.FlagPrefix, field, flagNameTag)
+		if flagName == "" {
+			continue
+		}
 
 		if err := l.setField(field, flagName, actualFlags); err != nil {
 			return err

aconfig_test.go

@@ -455,6 +455,40 @@ func TestExactName(t *testing.T) {
 	}
 }
 
+func TestSkipName(t *testing.T) {
+	setEnv(t, "STR", "str-env")
+	setEnv(t, "BAR", "bar-env")
+	defer os.Clearenv()
+
+	type Foo struct {
+		String string `env:"STR"`
+	}
+	type ExactConfig struct {
+		Foo Foo    `env:"-"`
+		Bar string `default:"def" env:"-"`
+	}
+	var cfg ExactConfig
+
+	loader := LoaderFor(&cfg, Config{
+		SkipFiles: true,
+		SkipFlags: true,
+	})
+	if err := loader.Load(); err != nil {
+		t.Fatal(err)
+	}
+
+	want := ExactConfig{
+		Foo: Foo{
+			String: "str-env",
+		},
+		Bar: "def",
+	}
+
+	if got := cfg; !reflect.DeepEqual(want, got) {
+		t.Fatalf("want %v, got %v", want, got)
+	}
+}
+
 func TestUsage(t *testing.T) {
 	loader := LoaderFor(&EmbeddedConfig{}, Config{})
 

reflection.go

@@ -78,11 +78,16 @@ func (l *Loader) fullTag(prefix string, f *fieldData, tag string) string {
 		sep = l.config.envDelimiter
 	}
 	res := f.Tag(tag)
+	if res == "-" {
+		return ""
+	}
 	if before, _, ok := cut(res, ",exact"); ok {
 		return before
 	}
 	for p := f.parent; p != nil; p = p.parent {
-		res = p.Tag(tag) + sep + res
+		if p.Tag(tag) != "-" {
+			res = p.Tag(tag) + sep + res
+		}
 	}
 	return prefix + res
 }