more tests

.golangci.yml

@@ -139,6 +139,9 @@ issues:
         - govet
     - path: _test\.go
       linters:
+        - cyclop
+        - forcetypeassert
         - funlen
+        - goconst
         - goerr113
         - wrapcheck

config.go

@@ -146,14 +146,15 @@ func sub(values map[string]any, keys []string) any {
 // If there are sensitive information (e.g. password, secret) which should not be exposed,
 // you can use [WithValueFormatter] to pass a value formatter to blur the information.
 func (c *Config) Explain(path string, opts ...ExplainOption) string {
-	option := &explainOptions{
-		valueFormatter: func(path string, loader Loader, value any) string {
-			return fmt.Sprint(value)
-		},
-	}
+	option := &explainOptions{}
 	for _, opt := range opts {
 		opt(option)
 	}
+	if option.valueFormatter == nil {
+		option.valueFormatter = func(path string, loader Loader, value any) string {
+			return fmt.Sprint(value)
+		}
+	}
 
 	explanation := &strings.Builder{}
 	c.explain(explanation, path, sub(c.values, strings.Split(path, c.delimiter)), *option)

config_test.go

@@ -5,12 +5,26 @@ package konf_test
 
 import (
 	"testing"
+	"time"
+
+	"github.com/go-viper/mapstructure/v2"
 
 	"github.com/nil-go/konf"
 	"github.com/nil-go/konf/internal/assert"
 	"github.com/nil-go/konf/provider/env"
 )
 
+func TestConfig_Load_panic(t *testing.T) {
+	t.Parallel()
+
+	defer func() {
+		if r := recover(); r != nil {
+			assert.Equal(t, r.(string), "cannot load config from nil loader")
+		}
+	}()
+	_ = konf.New().Load(nil)
+}
+
 func TestConfig_Unmarshal(t *testing.T) {
 	t.Parallel()
 
@@ -81,6 +95,44 @@ func TestConfig_Unmarshal(t *testing.T) {
 				assert.Equal(t, "string", value)
 			},
 		},
+		{
+			description: "customized decode hook",
+			opts: []konf.Option{
+				konf.WithDecodeHook(mapstructure.StringToTimeDurationHookFunc()),
+			},
+			loaders: []konf.Loader{
+				mapLoader{
+					"config": map[string]any{
+						"nest": "1s",
+					},
+				},
+			},
+			assert: func(config *konf.Config) {
+				var value time.Duration
+				assert.NoError(t, config.Unmarshal("config.nest", &value))
+				assert.Equal(t, time.Second, value)
+			},
+		},
+		{
+			description: "customized tag name",
+			opts: []konf.Option{
+				konf.WithTagName("test"),
+			},
+			loaders: []konf.Loader{
+				mapLoader{
+					"config": map[string]any{
+						"nest": "string",
+					},
+				},
+			},
+			assert: func(config *konf.Config) {
+				var value struct {
+					N string `test:"nest"`
+				}
+				assert.NoError(t, config.Unmarshal("config", &value))
+				assert.Equal(t, "string", value.N)
+			},
+		},
 		{
 			description: "non string key",
 			loaders: []konf.Loader{
@@ -132,7 +184,14 @@ func TestConfig_Explain(t *testing.T) {
 	assert.NoError(t, err)
 
 	assert.Equal(t, "non-exist has no configuration.\n\n", config.Explain("non-exist"))
-	assert.Equal(t, "owner has value[map] that is loaded by loader[map].\n\n", config.Explain("owner"))
+	assert.Equal(t,
+		"owner has value[map] that is loaded by loader[map].\n\n",
+		config.Explain("owner", konf.WithValueFormatter(
+			func(_ string, _ konf.Loader, value any) string {
+				return value.(string)
+			},
+		)),
+	)
 	expected := `config.nest has value[map] that is loaded by loader[map].
 Here are other value(loader)s:
   - env(env)

default_test.go

@@ -5,7 +5,6 @@ package konf_test
 
 import (
 	"bytes"
-	"log"
 	"testing"
 
 	"github.com/nil-go/konf"
@@ -37,18 +36,15 @@ func TestGet(t *testing.T) {
 }
 
 func TestGet_error(t *testing.T) {
-	config := konf.New()
+	buf := new(bytes.Buffer)
+	config := konf.New(konf.WithLogHandler(logHandler(buf)))
 	err := config.Load(mapLoader{"config": "string"})
 	assert.NoError(t, err)
 	konf.SetDefault(config)
 
-	buf := new(bytes.Buffer)
-	log.SetOutput(buf)
-	log.SetFlags(0)
-
 	assert.True(t, !konf.Get[bool]("config"))
-	expected := "WARN Could not read config, return empty value instead." +
-		" error=\"decode: cannot parse '' as bool: strconv.ParseBool: parsing \\\"string\\\": invalid syntax\"" +
-		" path=config type=bool\n"
+	expected := `level=WARN msg="Could not read config, return empty value instead."` +
+		` error="decode: cannot parse '' as bool: strconv.ParseBool: parsing \"string\": invalid syntax"` +
+		` path=config type=bool` + "\n"
 	assert.Equal(t, expected, buf.String())
 }

provider/appconfig/appconfig.go

@@ -30,7 +30,7 @@ type AppConfig struct {
 	logger    *slog.Logger
 	unmarshal func([]byte, any) error
 
-	client       appConfigClient
+	client       *appconfigdata.Client
 	application  string
 	environment  string
 	profile      string
@@ -39,19 +39,6 @@ type AppConfig struct {
 	token atomic.Pointer[string]
 }
 
-type appConfigClient interface {
-	StartConfigurationSession(
-		ctx context.Context,
-		params *appconfigdata.StartConfigurationSessionInput,
-		optFns ...func(*appconfigdata.Options),
-	) (*appconfigdata.StartConfigurationSessionOutput, error)
-	GetLatestConfiguration(
-		ctx context.Context,
-		params *appconfigdata.GetLatestConfigurationInput,
-		optFns ...func(*appconfigdata.Options),
-	) (*appconfigdata.GetLatestConfigurationOutput, error)
-}
-
 // New creates an AppConfig with the given application, environment, profile and Option(s).
 func New(application, environment, profile string, opts ...Option) *AppConfig {
 	if application == "" {