lint: fix errors

.golangci.yml

@@ -435,10 +435,13 @@ linters:
           - github.com/alexedwards/argon2id
           - github.com/google/uuid
           - github.com/hack-pad/hackpadfs
+          - github.com/hashicorp/hcl/v2
           - github.com/jessevdk/go-flags
+          - github.com/pelletier/go-toml/v2
           - github.com/pressly/goose/v3
           - github.com/PuerkitoBio/goquery
           - github.com/stretchr/testify
+          - gopkg.in/ini.v1
           - gopkg.in/yaml.v3
           - modernc.org/sqlite
         # List of allowed module domains.
@@ -2706,7 +2709,7 @@ linters:
       - path: _test\.go
         linters:
           - revive
-        text: "(comments-density|line-length-limit|unchecked-type-assertion)"
+        text: "(comments-density|line-length-limit|unchecked-type-assertion|cognitive-complexity)"
 
       # Run some linter only for test files by excluding its issues for everything else.
       #- path-except: _test\.go

adapters.go

@@ -18,6 +18,8 @@ import (
 	"gopkg.in/yaml.v3"
 )
 
+const errMsgConfigGen = "cannot generate config content: %w"
+
 func parseError(err error) error {
 	return fmt.Errorf("cannot parse config file: %w", err)
 }
@@ -105,7 +107,7 @@ func unmarshalJSON(data []byte, v any) error {
 func marshalJSON(v any) ([]byte, error) {
 	data, err := json.MarshalIndent(v, "", "  ")
 	if err != nil {
-		return nil, fmt.Errorf("cannot generate config content: %w", err)
+		return nil, fmt.Errorf(errMsgConfigGen, err)
 	}
 
 	return data, nil
@@ -125,7 +127,7 @@ func unmarshalTOML(data []byte, v any) error {
 func marshalTOML(v any) ([]byte, error) {
 	data, err := toml.Marshal(v)
 	if err != nil {
-		return nil, fmt.Errorf("cannot generate config content: %w", err)
+		return nil, fmt.Errorf(errMsgConfigGen, err)
 	}
 
 	return data, nil
@@ -185,7 +187,7 @@ func unmarshalYAML(data []byte, v any) error {
 func marshalYAML(v any) ([]byte, error) {
 	data, err := yaml.Marshal(v)
 	if err != nil {
-		return nil, fmt.Errorf("cannot generate config content: %w", err)
+		return nil, fmt.Errorf(errMsgConfigGen, err)
 	}
 
 	return data, nil
@@ -194,6 +196,7 @@ func marshalYAML(v any) ([]byte, error) {
 // unmarshalINI unmarshals the given data to the given struct.
 func unmarshalINI(data []byte, v any) error {
 	opts := ini.LoadOptions{}
+
 	cfg, err := ini.LoadSources(opts, data)
 	if err != nil {
 		return parseError(err)
@@ -220,25 +223,31 @@ func marshalINI(v any) ([]byte, error) {
 
 	err := ini.ReflectFromWithMapper(cfg, v, iniNameMapper)
 	if err != nil {
-		return nil, fmt.Errorf("cannot generate config content: %w", err)
+		return nil, fmt.Errorf("cannot generate config from struct: %w", err)
 	}
 
 	var buf bytes.Buffer
-	cfg.WriteTo(&buf)
-	data := buf.Bytes()
 
-	return data, nil
+	_, err = cfg.WriteTo(&buf)
+	if err != nil {
+		return nil, fmt.Errorf(errMsgConfigGen, err)
+	}
+
+	return buf.Bytes(), nil
 }
 
 func iniNameMapper(raw string) string {
 	newstr := make([]rune, 0, len(raw))
+
 	for i, chr := range raw {
 		if isUpper := 'A' <= chr && chr <= 'Z'; isUpper {
 			if i > 0 {
 				newstr = append(newstr, '_')
 			}
 		}
+
 		newstr = append(newstr, unicode.ToLower(chr))
 	}
+
 	return string(newstr)
 }

config_test.go

@@ -241,7 +241,7 @@ func testLoadFiles(t *testing.T, ext string) {
 			err := conf.LoadFiles(&c, "test_data/invalid."+ext, "test_data/valid."+ext)
 			require.Error(t, err)
 
-			assert.Equal(t, "", c.String)
+			assert.Empty(t, c.String)
 		})
 
 		t.Run("with a valid file and invalid data", func(t *testing.T) {