feat(encoding): drop HCL, Java properties and INI dependencies

Signed-off-by: Mark Sagi-Kazar <mark.sagikazar@gmail.com>

encoding.go

@@ -0,0 +1,169 @@
+package viper
+
+import (
+	"errors"
+	"strings"
+	"sync"
+
+	"github.com/spf13/viper/internal/encoding/dotenv"
+	"github.com/spf13/viper/internal/encoding/json"
+	"github.com/spf13/viper/internal/encoding/toml"
+	"github.com/spf13/viper/internal/encoding/yaml"
+)
+
+// Encoder encodes Viper's internal data structures into a byte representation.
+// It's primarily used for encoding a map[string]any into a file format.
+type Encoder interface {
+	Encode(v map[string]any) ([]byte, error)
+}
+
+// Decoder decodes the contents of a byte slice into Viper's internal data structures.
+// It's primarily used for decoding contents of a file into a map[string]any.
+type Decoder interface {
+	Decode(b []byte, v map[string]any) error
+}
+
+// Codec combines [Encoder] and [Decoder] interfaces.
+type Codec interface {
+	Encoder
+	Decoder
+}
+
+// TODO: consider adding specific errors for not found scenarios
+
+// EncoderRegistry returns an [Encoder] for a given format.
+//
+// Format is case-insensitive.
+//
+// [EncoderRegistry] returns an error if no [Encoder] is registered for the format.
+type EncoderRegistry interface {
+	Encoder(format string) (Encoder, error)
+}
+
+// DecoderRegistry returns an [Decoder] for a given format.
+//
+// Format is case-insensitive.
+//
+// [DecoderRegistry] returns an error if no [Decoder] is registered for the format.
+type DecoderRegistry interface {
+	Decoder(format string) (Decoder, error)
+}
+
+// [CodecRegistry] combines [EncoderRegistry] and [DecoderRegistry] interfaces.
+type CodecRegistry interface {
+	EncoderRegistry
+	DecoderRegistry
+}
+
+// WithEncoderRegistry sets a custom [EncoderRegistry].
+func WithEncoderRegistry(r EncoderRegistry) Option {
+	return optionFunc(func(v *Viper) {
+		v.encoderRegistry = r
+	})
+}
+
+// WithDecoderRegistry sets a custom [DecoderRegistry].
+func WithDecoderRegistry(r DecoderRegistry) Option {
+	return optionFunc(func(v *Viper) {
+		v.decoderRegistry = r
+	})
+}
+
+// WithCodecRegistry sets a custom [EncoderRegistry] and [DecoderRegistry].
+func WithCodecRegistry(r CodecRegistry) Option {
+	return optionFunc(func(v *Viper) {
+		v.encoderRegistry = r
+		v.decoderRegistry = r
+	})
+}
+
+// DefaultCodecRegistry is a simple implementation of [CodecRegistry] that allows registering custom [Codec]s.
+type DefaultCodecRegistry struct {
+	codecs map[string]Codec
+
+	mu   sync.RWMutex
+	once sync.Once
+}
+
+// NewCodecRegistry returns a new [CodecRegistry], ready to accept custom [Codec]s.
+func NewCodecRegistry() *DefaultCodecRegistry {
+	r := &DefaultCodecRegistry{}
+
+	r.init()
+
+	return r
+}
+
+func (r *DefaultCodecRegistry) init() {
+	r.once.Do(func() {
+		r.codecs = map[string]Codec{}
+	})
+}
+
+// RegisterCodec registers a custom [Codec].
+//
+// Format is case-insensitive.
+func (r *DefaultCodecRegistry) RegisterCodec(format string, codec Codec) error {
+	r.init()
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	r.codecs[strings.ToLower(format)] = codec
+
+	return nil
+}
+
+// Encoder implements the [EncoderRegistry] interface.
+//
+// Format is case-insensitive.
+func (r *DefaultCodecRegistry) Encoder(format string) (Encoder, error) {
+	encoder, ok := r.codec(format)
+	if !ok {
+		return nil, errors.New("encoder not found for this format")
+	}
+
+	return encoder, nil
+}
+
+// Decoder implements the [DecoderRegistry] interface.
+//
+// Format is case-insensitive.
+func (r *DefaultCodecRegistry) Decoder(format string) (Decoder, error) {
+	decoder, ok := r.codec(format)
+	if !ok {
+		return nil, errors.New("decoder not found for this format")
+	}
+
+	return decoder, nil
+}
+
+func (r *DefaultCodecRegistry) codec(format string) (Codec, bool) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	format = strings.ToLower(format)
+
+	if r.codecs != nil {
+		codec, ok := r.codecs[format]
+		if ok {
+			return codec, true
+		}
+	}
+
+	switch format {
+	case "yaml", "yml":
+		return yaml.Codec{}, true
+
+	case "json":
+		return json.Codec{}, true
+
+	case "toml":
+		return toml.Codec{}, true
+
+	case "dotenv", "env":
+		return &dotenv.Codec{}, true
+	}
+
+	return nil, false
+}

encoding_test.go

@@ -0,0 +1,105 @@
+package viper
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type codec struct{}
+
+func (codec) Encode(_ map[string]any) ([]byte, error) {
+	return nil, nil
+}
+
+func (codec) Decode(_ []byte, _ map[string]any) error {
+	return nil
+}
+
+func TestDefaultCodecRegistry(t *testing.T) {
+	t.Run("OK", func(t *testing.T) {
+		registry := NewCodecRegistry()
+
+		c := codec{}
+
+		err := registry.RegisterCodec("myformat", c)
+		require.NoError(t, err)
+
+		encoder, err := registry.Encoder("myformat")
+		require.NoError(t, err)
+
+		assert.Equal(t, c, encoder)
+
+		decoder, err := registry.Decoder("myformat")
+		require.NoError(t, err)
+
+		assert.Equal(t, c, decoder)
+	})
+
+	t.Run("CodecNotFound", func(t *testing.T) {
+		registry := NewCodecRegistry()
+
+		_, err := registry.Encoder("myformat")
+		require.Error(t, err)
+
+		_, err = registry.Decoder("myformat")
+		require.Error(t, err)
+	})
+
+	t.Run("FormatIsCaseInsensitive", func(t *testing.T) {
+		registry := NewCodecRegistry()
+
+		c := codec{}
+
+		err := registry.RegisterCodec("MYFORMAT", c)
+		require.NoError(t, err)
+
+		{
+			encoder, err := registry.Encoder("myformat")
+			require.NoError(t, err)
+
+			assert.Equal(t, c, encoder)
+		}
+
+		{
+			encoder, err := registry.Encoder("MYFORMAT")
+			require.NoError(t, err)
+
+			assert.Equal(t, c, encoder)
+		}
+
+		{
+			decoder, err := registry.Decoder("myformat")
+			require.NoError(t, err)
+
+			assert.Equal(t, c, decoder)
+		}
+
+		{
+			decoder, err := registry.Decoder("MYFORMAT")
+			require.NoError(t, err)
+
+			assert.Equal(t, c, decoder)
+		}
+	})
+
+	t.Run("OverrideDefault", func(t *testing.T) {
+		registry := NewCodecRegistry()
+
+		c := codec{}
+
+		err := registry.RegisterCodec("yaml", c)
+		require.NoError(t, err)
+
+		encoder, err := registry.Encoder("yaml")
+		require.NoError(t, err)
+
+		assert.Equal(t, c, encoder)
+
+		decoder, err := registry.Decoder("yaml")
+		require.NoError(t, err)
+
+		assert.Equal(t, c, decoder)
+	})
+}

go.mod

@@ -4,33 +4,24 @@ go 1.21
 
 require (
 	github.com/fsnotify/fsnotify v1.7.0
-	github.com/go-viper/encoding/dotenv v0.1.0
-	github.com/go-viper/encoding/hcl v0.1.0
-	github.com/go-viper/encoding/ini v0.1.0
-	github.com/go-viper/encoding/javaproperties v0.1.0
-	github.com/go-viper/encoding/toml v0.1.0
-	github.com/go-viper/encoding/yaml v0.1.0
 	github.com/go-viper/mapstructure/v2 v2.0.0
+	github.com/pelletier/go-toml/v2 v2.2.2
 	github.com/sagikazarmark/locafero v0.6.0
 	github.com/spf13/afero v1.11.0
 	github.com/spf13/cast v1.6.0
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.9.0
+	github.com/subosito/gotenv v1.6.0
+	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/go-cmp v0.6.0 // indirect
-	github.com/hashicorp/hcl v1.0.0 // indirect
-	github.com/magiconair/properties v1.8.7 // indirect
-	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/sourcegraph/conc v0.3.0 // indirect
-	github.com/subosito/gotenv v1.6.0 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.9.0 // indirect
 	golang.org/x/sys v0.20.0 // indirect
 	golang.org/x/text v0.15.0 // indirect
-	gopkg.in/ini.v1 v1.67.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -5,30 +5,14 @@ github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHk
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nosvA=
 github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
-github.com/go-viper/encoding/dotenv v0.1.0 h1:XelRj/HPBriYmnXY59h1QLMBnmWC21qFojzr9vdzbZo=
-github.com/go-viper/encoding/dotenv v0.1.0/go.mod h1:SF1B9MODzZ1OLBEePSrjMkJjVg821fFiYea5AIL8CBc=
-github.com/go-viper/encoding/hcl v0.1.0 h1:eC0Vo0XLTkWMd0ehSeF4H2ushiKu/lwNAzYnStgTkho=
-github.com/go-viper/encoding/hcl v0.1.0/go.mod h1:uXPhzJnVyTb45tuW8lqhcUDe7DYvrZFoZs0HU9vXOyg=
-github.com/go-viper/encoding/ini v0.1.0 h1:zzt54JVGIAFGIPYzqauMgJt7gjh9hVC3S+NzWJPvb9Y=
-github.com/go-viper/encoding/ini v0.1.0/go.mod h1:Pfi4M2V1eAGJVZ5q6FrkHPhtHED2YgLlXhvgMVrB+YQ=
-github.com/go-viper/encoding/javaproperties v0.1.0 h1:4pQN/pez/rMy9ITZ++SgLH6VIN3zWzNNuWFHKjrpn6w=
-github.com/go-viper/encoding/javaproperties v0.1.0/go.mod h1:LGaThjx5J/GFdQRJscxLMQsYt0XKAM7IW9YzsJTv6jw=
-github.com/go-viper/encoding/toml v0.1.0 h1:Gtd343g0JR9lLeBaudZILjLPYiGmzyE0LSpTf6HsYDU=
-github.com/go-viper/encoding/toml v0.1.0/go.mod h1:+gJiMxUZ/wslHYy06NBtkotxZ7fbue+36KvdMm2OXTk=
-github.com/go-viper/encoding/yaml v0.1.0 h1:tILva5u4EUgtJDYhAB7U+aj5zIDZqmq5qvcS8U4bFQE=
-github.com/go-viper/encoding/yaml v0.1.0/go.mod h1:nsYhB8GzJ0rVF6sA0Xiok0mEuHtmHqmCn5tUuKKAwv0=
 github.com/go-viper/mapstructure/v2 v2.0.0 h1:dhn8MZ1gZ0mzeodTG3jt5Vj/o87xZKuNAprG2mQfMfc=
 github.com/go-viper/mapstructure/v2 v2.0.0/go.mod h1:oJDH3BJKyqBA2TXFhDsKDGDTlndYOZ6rGS0BRZIxGhM=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
-github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
-github.com/magiconair/properties v1.8.7 h1:IeQXZAiQcpL9mgcAe1Nu6cX9LLw6ExEHKjN0VQdvPDY=
-github.com/magiconair/properties v1.8.7/go.mod h1:Dhd985XPs7jluiymwWYZ0G4Z61jb3vdS329zhj2hYo0=
 github.com/pelletier/go-toml/v2 v2.2.2 h1:aYUidT7k73Pcl9nb2gScu7NSrKCSHIDE89b3+6Wq+LM=
 github.com/pelletier/go-toml/v2 v2.2.2/go.mod h1:1t835xjRzz80PqgE6HHgN2JOsmgYu/h4qDAS4n929Rs=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -68,8 +52,6 @@ golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
-gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/encoding/dotenv/codec.go

@@ -0,0 +1,61 @@
+package dotenv
+
+import (
+	"bytes"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/subosito/gotenv"
+)
+
+const keyDelimiter = "_"
+
+// Codec implements the encoding.Encoder and encoding.Decoder interfaces for encoding data containing environment variables
+// (commonly called as dotenv format).
+type Codec struct{}
+
+func (Codec) Encode(v map[string]any) ([]byte, error) {
+	flattened := map[string]any{}
+
+	flattened = flattenAndMergeMap(flattened, v, "", keyDelimiter)
+
+	keys := make([]string, 0, len(flattened))
+
+	for key := range flattened {
+		keys = append(keys, key)
+	}
+
+	sort.Strings(keys)
+
+	var buf bytes.Buffer
+
+	for _, key := range keys {
+		_, err := buf.WriteString(fmt.Sprintf("%v=%v\n", strings.ToUpper(key), flattened[key]))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return buf.Bytes(), nil
+}
+
+func (Codec) Decode(b []byte, v map[string]any) error {
+	var buf bytes.Buffer
+
+	_, err := buf.Write(b)
+	if err != nil {
+		return err
+	}
+
+	env, err := gotenv.StrictParse(&buf)
+	if err != nil {
+		return err
+	}
+
+	for key, value := range env {
+		v[key] = value
+	}
+
+	return nil
+}

internal/encoding/dotenv/codec_test.go

@@ -0,0 +1,55 @@
+package dotenv
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// original form of the data.
+const original = `# key-value pair
+KEY=value
+`
+
+// encoded form of the data.
+const encoded = `KEY=value
+`
+
+// data is Viper's internal representation.
+var data = map[string]any{
+	"KEY": "value",
+}
+
+func TestCodec_Encode(t *testing.T) {
+	codec := Codec{}
+
+	b, err := codec.Encode(data)
+	require.NoError(t, err)
+
+	assert.Equal(t, encoded, string(b))
+}
+
+func TestCodec_Decode(t *testing.T) {
+	t.Run("OK", func(t *testing.T) {
+		codec := Codec{}
+
+		v := map[string]any{}
+
+		err := codec.Decode([]byte(original), v)
+		require.NoError(t, err)
+
+		assert.Equal(t, data, v)
+	})
+
+	t.Run("InvalidData", func(t *testing.T) {
+		codec := Codec{}
+
+		v := map[string]any{}
+
+		err := codec.Decode([]byte(`invalid data`), v)
+		require.Error(t, err)
+
+		t.Logf("decoding failed as expected: %s", err)
+	})
+}

internal/encoding/dotenv/map_utils.go

@@ -0,0 +1,41 @@
+package dotenv
+
+import (
+	"strings"
+
+	"github.com/spf13/cast"
+)
+
+// flattenAndMergeMap recursively flattens the given map into a new map
+// Code is based on the function with the same name in the main package.
+// TODO: move it to a common place.
+func flattenAndMergeMap(shadow, m map[string]any, prefix, delimiter string) map[string]any {
+	if shadow != nil && prefix != "" && shadow[prefix] != nil {
+		// prefix is shadowed => nothing more to flatten
+		return shadow
+	}
+	if shadow == nil {
+		shadow = make(map[string]any)
+	}
+
+	var m2 map[string]any
+	if prefix != "" {
+		prefix += delimiter
+	}
+	for k, val := range m {
+		fullKey := prefix + k
+		switch val := val.(type) {
+		case map[string]any:
+			m2 = val
+		case map[any]any:
+			m2 = cast.ToStringMap(val)
+		default:
+			// immediate value
+			shadow[strings.ToLower(fullKey)] = val
+			continue
+		}
+		// recursively merge to shadow map
+		shadow = flattenAndMergeMap(shadow, m2, fullKey, delimiter)
+	}
+	return shadow
+}

internal/encoding/toml/codec.go

@@ -0,0 +1,16 @@
+package toml
+
+import (
+	"github.com/pelletier/go-toml/v2"
+)
+
+// Codec implements the encoding.Encoder and encoding.Decoder interfaces for TOML encoding.
+type Codec struct{}
+
+func (Codec) Encode(v map[string]any) ([]byte, error) {
+	return toml.Marshal(v)
+}
+
+func (Codec) Decode(b []byte, v map[string]any) error {
+	return toml.Unmarshal(b, &v)
+}

internal/encoding/toml/codec_test.go

@@ -0,0 +1,97 @@
+package toml
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// original form of the data.
+const original = `# key-value pair
+key = "value"
+list = ["item1", "item2", "item3"]
+
+[map]
+key = "value"
+
+# nested
+# map
+[nested_map]
+[nested_map.map]
+key = "value"
+list = [
+  "item1",
+  "item2",
+  "item3",
+]
+`
+
+// encoded form of the data.
+const encoded = `key = 'value'
+list = ['item1', 'item2', 'item3']
+
+[map]
+key = 'value'
+
+[nested_map]
+[nested_map.map]
+key = 'value'
+list = ['item1', 'item2', 'item3']
+`
+
+// data is Viper's internal representation.
+var data = map[string]any{
+	"key": "value",
+	"list": []any{
+		"item1",
+		"item2",
+		"item3",
+	},
+	"map": map[string]any{
+		"key": "value",
+	},
+	"nested_map": map[string]any{
+		"map": map[string]any{
+			"key": "value",
+			"list": []any{
+				"item1",
+				"item2",
+				"item3",
+			},
+		},
+	},
+}
+
+func TestCodec_Encode(t *testing.T) {
+	codec := Codec{}
+
+	b, err := codec.Encode(data)
+	require.NoError(t, err)
+
+	assert.Equal(t, encoded, string(b))
+}
+
+func TestCodec_Decode(t *testing.T) {
+	t.Run("OK", func(t *testing.T) {
+		codec := Codec{}
+
+		v := map[string]any{}
+
+		err := codec.Decode([]byte(original), v)
+		require.NoError(t, err)
+
+		assert.Equal(t, data, v)
+	})
+
+	t.Run("InvalidData", func(t *testing.T) {
+		codec := Codec{}
+
+		v := map[string]any{}
+
+		err := codec.Decode([]byte(`invalid data`), v)
+		require.Error(t, err)
+
+		t.Logf("decoding failed as expected: %s", err)
+	})
+}

internal/encoding/yaml/codec.go

@@ -0,0 +1,14 @@
+package yaml
+
+import "gopkg.in/yaml.v3"
+
+// Codec implements the encoding.Encoder and encoding.Decoder interfaces for YAML encoding.
+type Codec struct{}
+
+func (Codec) Encode(v map[string]any) ([]byte, error) {
+	return yaml.Marshal(v)
+}
+
+func (Codec) Decode(b []byte, v map[string]any) error {
+	return yaml.Unmarshal(b, &v)
+}

internal/encoding/yaml/codec_test.go

@@ -0,0 +1,128 @@
+package yaml
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// original form of the data.
+const original = `# key-value pair
+key: value
+list:
+    - item1
+    - item2
+    - item3
+map:
+    key: value
+
+# nested
+# map
+nested_map:
+    map:
+        key: value
+        list:
+            - item1
+            - item2
+            - item3
+`
+
+// encoded form of the data.
+const encoded = `key: value
+list:
+    - item1
+    - item2
+    - item3
+map:
+    key: value
+nested_map:
+    map:
+        key: value
+        list:
+            - item1
+            - item2
+            - item3
+`
+
+// decoded form of the data.
+//
+// In case of YAML it's slightly different from Viper's internal representation
+// (e.g. map is decoded into a map with interface key).
+var decoded = map[string]any{
+	"key": "value",
+	"list": []any{
+		"item1",
+		"item2",
+		"item3",
+	},
+	"map": map[string]any{
+		"key": "value",
+	},
+	"nested_map": map[string]any{
+		"map": map[string]any{
+			"key": "value",
+			"list": []any{
+				"item1",
+				"item2",
+				"item3",
+			},
+		},
+	},
+}
+
+// data is Viper's internal representation.
+var data = map[string]any{
+	"key": "value",
+	"list": []any{
+		"item1",
+		"item2",
+		"item3",
+	},
+	"map": map[string]any{
+		"key": "value",
+	},
+	"nested_map": map[string]any{
+		"map": map[string]any{
+			"key": "value",
+			"list": []any{
+				"item1",
+				"item2",
+				"item3",
+			},
+		},
+	},
+}
+
+func TestCodec_Encode(t *testing.T) {
+	codec := Codec{}
+
+	b, err := codec.Encode(data)
+	require.NoError(t, err)
+
+	assert.Equal(t, encoded, string(b))
+}
+
+func TestCodec_Decode(t *testing.T) {
+	t.Run("OK", func(t *testing.T) {
+		codec := Codec{}
+
+		v := map[string]any{}
+
+		err := codec.Decode([]byte(original), v)
+		require.NoError(t, err)
+
+		assert.Equal(t, decoded, v)
+	})
+
+	t.Run("InvalidData", func(t *testing.T) {
+		codec := Codec{}
+
+		v := map[string]any{}
+
+		err := codec.Decode([]byte(`invalid data`), v)
+		require.Error(t, err)
+
+		t.Logf("decoding failed as expected: %s", err)
+	})
+}

viper.go

@@ -35,19 +35,11 @@ import (
 	"time"
 
 	"github.com/fsnotify/fsnotify"
-	"github.com/go-viper/encoding/dotenv"
-	"github.com/go-viper/encoding/hcl"
-	"github.com/go-viper/encoding/ini"
-	"github.com/go-viper/encoding/javaproperties"
-	"github.com/go-viper/encoding/toml"
-	"github.com/go-viper/encoding/yaml"
 	"github.com/go-viper/mapstructure/v2"
 	"github.com/spf13/afero"
 	"github.com/spf13/cast"
 	"github.com/spf13/pflag"
 
-	"github.com/spf13/viper/internal/encoding"
-	"github.com/spf13/viper/internal/encoding/json"
 	"github.com/spf13/viper/internal/features"
 )
 
@@ -170,9 +162,6 @@ type Viper struct {
 	configPermissions os.FileMode
 	envPrefix         string
 
-	// Specific commands for ini parsing
-	iniLoadOptions ini.LoadOptions
-
 	automaticEnvApplied bool
 	envKeyReplacer      StringReplacer
 	allowEmptyEnv       bool
@@ -191,9 +180,8 @@ type Viper struct {
 
 	logger *slog.Logger
 
-	// TODO: should probably be protected with a mutex
-	encoderRegistry *encoding.EncoderRegistry
-	decoderRegistry *encoding.DecoderRegistry
+	encoderRegistry EncoderRegistry
+	decoderRegistry DecoderRegistry
 
 	experimentalFinder     bool
 	experimentalBindStruct bool
@@ -217,7 +205,10 @@ func New() *Viper {
 	v.typeByDefValue = false
 	v.logger = slog.New(&discardHandler{})
 
-	v.resetEncoding()
+	codecRegistry := NewCodecRegistry()
+
+	v.encoderRegistry = codecRegistry
+	v.decoderRegistry = codecRegistry
 
 	v.experimentalFinder = features.Finder
 	v.experimentalBindStruct = features.BindStruct
@@ -268,8 +259,6 @@ func NewWithOptions(opts ...Option) *Viper {
 		opt.apply(v)
 	}
 
-	v.resetEncoding()
-
 	return v
 }
 
@@ -278,16 +267,9 @@ func NewWithOptions(opts ...Option) *Viper {
 // Be careful when using this function: subsequent calls may override options you set.
 // It's always better to use a local Viper instance.
 func SetOptions(opts ...Option) {
-	keyDelim := v.keyDelim
-
 	for _, opt := range opts {
 		opt.apply(v)
 	}
-
-	// reset encoding if key delimiter changed
-	if keyDelim != v.keyDelim {
-		v.resetEncoding()
-	}
 }
 
 // Reset is intended for testing, will reset all to default settings.
@@ -300,84 +282,6 @@ func Reset() {
 	resetRemote()
 }
 
-// TODO: make this lazy initialization instead.
-func (v *Viper) resetEncoding() {
-	encoderRegistry := encoding.NewEncoderRegistry()
-	decoderRegistry := encoding.NewDecoderRegistry()
-
-	{
-		codec := yaml.Codec{}
-
-		encoderRegistry.RegisterEncoder("yaml", codec)
-		decoderRegistry.RegisterDecoder("yaml", codec)
-
-		encoderRegistry.RegisterEncoder("yml", codec)
-		decoderRegistry.RegisterDecoder("yml", codec)
-	}
-
-	{
-		codec := json.Codec{}
-
-		encoderRegistry.RegisterEncoder("json", codec)
-		decoderRegistry.RegisterDecoder("json", codec)
-	}
-
-	{
-		codec := toml.Codec{}
-
-		encoderRegistry.RegisterEncoder("toml", codec)
-		decoderRegistry.RegisterDecoder("toml", codec)
-	}
-
-	{
-		codec := hcl.Codec{}
-
-		encoderRegistry.RegisterEncoder("hcl", codec)
-		decoderRegistry.RegisterDecoder("hcl", codec)
-
-		encoderRegistry.RegisterEncoder("tfvars", codec)
-		decoderRegistry.RegisterDecoder("tfvars", codec)
-	}
-
-	{
-		codec := ini.Codec{
-			KeyDelimiter: v.keyDelim,
-			LoadOptions:  v.iniLoadOptions,
-		}
-
-		encoderRegistry.RegisterEncoder("ini", codec)
-		decoderRegistry.RegisterDecoder("ini", codec)
-	}
-
-	{
-		codec := &javaproperties.Codec{
-			KeyDelimiter: v.keyDelim,
-		}
-
-		encoderRegistry.RegisterEncoder("properties", codec)
-		decoderRegistry.RegisterDecoder("properties", codec)
-
-		encoderRegistry.RegisterEncoder("props", codec)
-		decoderRegistry.RegisterDecoder("props", codec)
-
-		encoderRegistry.RegisterEncoder("prop", codec)
-		decoderRegistry.RegisterDecoder("prop", codec)
-	}
-
-	{
-		codec := &dotenv.Codec{}
-
-		encoderRegistry.RegisterEncoder("dotenv", codec)
-		decoderRegistry.RegisterDecoder("dotenv", codec)
-
-		encoderRegistry.RegisterEncoder("env", codec)
-		decoderRegistry.RegisterDecoder("env", codec)
-	}
-
-	v.encoderRegistry = encoderRegistry
-	v.decoderRegistry = decoderRegistry
-}
-
 // SupportedExts are universally supported extensions.
 var SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "tfvars", "dotenv", "env", "ini"}
 
@@ -1715,7 +1619,12 @@ func (v *Viper) unmarshalReader(in io.Reader, c map[string]any) error {
 
 	switch format := strings.ToLower(v.getConfigType()); format {
 	case "yaml", "yml", "json", "toml", "hcl", "tfvars", "ini", "properties", "props", "prop", "dotenv", "env":
-		err := v.decoderRegistry.Decode(format, buf.Bytes(), c)
+		decoder, err := v.decoderRegistry.Decoder(format)
+		if err != nil {
+			return ConfigParseError{err}
+		}
+
+		err = decoder.Decode(buf.Bytes(), c)
 		if err != nil {
 			return ConfigParseError{err}
 		}
@@ -1730,7 +1639,12 @@ func (v *Viper) marshalWriter(f afero.File, configType string) error {
 	c := v.AllSettings()
 	switch configType {
 	case "yaml", "yml", "json", "toml", "hcl", "tfvars", "ini", "prop", "props", "properties", "dotenv", "env":
-		b, err := v.encoderRegistry.Encode(configType, c)
+		encoder, err := v.encoderRegistry.Encoder(configType)
+		if err != nil {
+			return ConfigMarshalError{err}
+		}
+
+		b, err := encoder.Encode(c)
 		if err != nil {
 			return ConfigMarshalError{err}
 		}
@@ -2019,13 +1933,6 @@ func (v *Viper) SetConfigPermissions(perm os.FileMode) {
 	v.configPermissions = perm.Perm()
 }
 
-// IniLoadOptions sets the load options for ini parsing.
-func IniLoadOptions(in ini.LoadOptions) Option {
-	return optionFunc(func(v *Viper) {
-		v.iniLoadOptions = in
-	})
-}
-
 func (v *Viper) getConfigType() string {
 	if v.configType != "" {
 		return v.configType

viper_test.go

@@ -84,58 +84,12 @@ var jsonExample = []byte(`{
     }
 }`)
 
-var hclExample = []byte(`
-id = "0001"
-type = "donut"
-name = "Cake"
-ppu = 0.55
-foos {
-	foo {
-		key = 1
-	}
-	foo {
-		key = 2
-	}
-	foo {
-		key = 3
-	}
-	foo {
-		key = 4
-	}
-}`)
-
-var propertiesExample = []byte(`
-p_id: 0001
-p_type: donut
-p_name: Cake
-p_ppu: 0.55
-p_batters.batter.type: Regular
-`)
-
 var remoteExample = []byte(`{
 "id":"0002",
 "type":"cronut",
 "newkey":"remote"
 }`)
 
-var iniExample = []byte(`; Package name
-NAME        = ini
-; Package version
-VERSION     = v1
-; Package import path
-IMPORT_PATH = gopkg.in/%(NAME)s.%(VERSION)s
-
-# Information about package author
-# Bio can be written in multiple lines.
-[author]
-NAME   = Unknown  ; Succeeding comment
-E-MAIL = fake@localhost
-GITHUB = https://github.com/%(NAME)s
-BIO    = """Gopher.
-Coding addict.
-Good man.
-"""  # Succeeding comment`)
-
 func initConfigs(v *Viper) {
 	var r io.Reader
 	v.SetConfigType("yaml")
@@ -146,14 +100,6 @@ func initConfigs(v *Viper) {
 	r = bytes.NewReader(jsonExample)
 	v.unmarshalReader(r, v.config)
 
-	v.SetConfigType("hcl")
-	r = bytes.NewReader(hclExample)
-	v.unmarshalReader(r, v.config)
-
-	v.SetConfigType("properties")
-	r = bytes.NewReader(propertiesExample)
-	v.unmarshalReader(r, v.config)
-
 	v.SetConfigType("toml")
 	r = bytes.NewReader(tomlExample)
 	v.unmarshalReader(r, v.config)
@@ -165,10 +111,6 @@ func initConfigs(v *Viper) {
 	v.SetConfigType("json")
 	remote := bytes.NewReader(remoteExample)
 	v.unmarshalReader(remote, v.kvstore)
-
-	v.SetConfigType("ini")
-	r = bytes.NewReader(iniExample)
-	v.unmarshalReader(r, v.config)
 }
 
 func initConfig(typ, config string, v *Viper) {
@@ -622,22 +564,11 @@ func TestJSON(t *testing.T) {
 	assert.Equal(t, "0001", v.Get("id"))
 }
 
-func TestProperties(t *testing.T) {
-	v := New()
-
-	v.SetConfigType("properties")
-
-	// Read the properties data into Viper configuration
-	require.NoError(t, v.ReadConfig(bytes.NewBuffer(propertiesExample)), "Error reading properties data")
-
-	assert.Equal(t, "0001", v.Get("p_id"))
-}
-
 func TestTOML(t *testing.T) {
 	v := New()
 	v.SetConfigType("toml")
 
-	// Read the properties data into Viper configuration
+	// Read the TOML data into Viper configuration
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(tomlExample)), "Error reading toml data")
 
 	assert.Equal(t, "TOML Example", v.Get("title"))
@@ -646,42 +577,16 @@ func TestTOML(t *testing.T) {
 func TestDotEnv(t *testing.T) {
 	v := New()
 	v.SetConfigType("env")
-	// Read the properties data into Viper configuration
+	// Read the dotenv data into Viper configuration
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(dotenvExample)), "Error reading env data")
 
 	assert.Equal(t, "DotEnv Example", v.Get("title_dotenv"))
 }
 
-func TestHCL(t *testing.T) {
-	v := New()
-	v.SetConfigType("hcl")
-	// Read the properties data into Viper configuration
-	require.NoError(t, v.ReadConfig(bytes.NewBuffer(hclExample)), "Error reading hcl data")
-
-	// initHcl()
-	assert.Equal(t, "0001", v.Get("id"))
-	assert.Equal(t, 0.55, v.Get("ppu"))
-	assert.Equal(t, "donut", v.Get("type"))
-	assert.Equal(t, "Cake", v.Get("name"))
-	v.Set("id", "0002")
-	assert.Equal(t, "0002", v.Get("id"))
-	assert.NotEqual(t, "cronut", v.Get("type"))
-}
-
-func TestIni(t *testing.T) {
-	// initIni()
-	v := New()
-	v.SetConfigType("ini")
-	// Read the properties data into Viper configuration
-	require.NoError(t, v.ReadConfig(bytes.NewBuffer(iniExample)), "Error reading ini data")
-
-	assert.Equal(t, "ini", v.Get("default.name"))
-}
-
 func TestRemotePrecedence(t *testing.T) {
 	v := New()
 	v.SetConfigType("json")
-	// Read the properties data into Viper configuration v.config
+	// Read the remote data into Viper configuration v.config
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(jsonExample)), "Error reading json data")
 
 	assert.Equal(t, "0001", v.Get("id"))
@@ -701,7 +606,7 @@ func TestRemotePrecedence(t *testing.T) {
 func TestEnv(t *testing.T) {
 	v := New()
 	v.SetConfigType("json")
-	// Read the properties data into Viper configuration v.config
+	// Read the JSON data into Viper configuration v.config
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(jsonExample)), "Error reading json data")
 
 	v.BindEnv("id")
@@ -724,7 +629,7 @@ func TestEnv(t *testing.T) {
 func TestMultipleEnv(t *testing.T) {
 	v := New()
 	v.SetConfigType("json")
-	// Read the properties data into Viper configuration v.config
+	// Read the JSON data into Viper configuration v.config
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(jsonExample)), "Error reading json data")
 
 	v.BindEnv("f", "FOOD", "OLD_FOOD")
@@ -737,7 +642,7 @@ func TestMultipleEnv(t *testing.T) {
 func TestEmptyEnv(t *testing.T) {
 	v := New()
 	v.SetConfigType("json")
-	// Read the properties data into Viper configuration v.config
+	// Read the JSON data into Viper configuration v.config
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(jsonExample)), "Error reading json data")
 
 	v.BindEnv("type") // Empty environment variable
@@ -752,7 +657,7 @@ func TestEmptyEnv(t *testing.T) {
 func TestEmptyEnv_Allowed(t *testing.T) {
 	v := New()
 	v.SetConfigType("json")
-	// Read the properties data into Viper configuration v.config
+	// Read the JSON data into Viper configuration v.config
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(jsonExample)), "Error reading json data")
 
 	v.AllowEmptyEnv(true)
@@ -769,7 +674,7 @@ func TestEmptyEnv_Allowed(t *testing.T) {
 func TestEnvPrefix(t *testing.T) {
 	v := New()
 	v.SetConfigType("json")
-	// Read the properties data into Viper configuration v.config
+	// Read the JSON data into Viper configuration v.config
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(jsonExample)), "Error reading json data")
 
 	v.SetEnvPrefix("foo") // will be uppercased automatically
@@ -829,7 +734,7 @@ func TestEnvKeyReplacer(t *testing.T) {
 func TestEnvSubConfig(t *testing.T) {
 	v := New()
 	v.SetConfigType("yaml")
-	// Read the properties data into Viper configuration v.config
+	// Read the YAML data into Viper configuration v.config
 	require.NoError(t, v.ReadConfig(bytes.NewBuffer(yamlExample)), "Error reading json data")
 	v.AutomaticEnv()
 	v.SetEnvKeyReplacer(strings.NewReplacer(".", "_"))
@@ -851,10 +756,6 @@ func TestAllKeys(t *testing.T) {
 
 	ks := []string{
 		"title",
-		"author.bio",
-		"author.e-mail",
-		"author.github",
-		"author.name",
 		"newkey",
 		"owner.organization",
 		"owner.dob",
@@ -866,21 +767,12 @@ func TestAllKeys(t *testing.T) {
 		"hobbies",
 		"clothing.jacket",
 		"clothing.trousers",
-		"default.import_path",
-		"default.name",
-		"default.version",
 		"clothing.pants.size",
 		"age",
 		"hacker",
 		"id",
 		"type",
 		"eyes",
-		"p_id",
-		"p_ppu",
-		"p_batters.batter.type",
-		"p_type",
-		"p_name",
-		"foos",
 		"title_dotenv",
 		"type_dotenv",
 		"name_dotenv",
@@ -893,24 +785,13 @@ func TestAllKeys(t *testing.T) {
 			"dob":          dob,
 		},
 		"title": "TOML Example",
-		"author": map[string]any{
-			"e-mail": "fake@localhost",
-			"github": "https://github.com/Unknown",
-			"name":   "Unknown",
-			"bio":    "Gopher.\nCoding addict.\nGood man.\n",
-		},
-		"ppu":  0.55,
-		"eyes": "brown",
+		"ppu":   0.55,
+		"eyes":  "brown",
 		"clothing": map[string]any{
 			"trousers": "denim",
 			"jacket":   "leather",
 			"pants":    map[string]any{"size": "large"},
 		},
-		"default": map[string]any{
-			"import_path": "gopkg.in/ini.v1",
-			"name":        "ini",
-			"version":     "v1",
-		},
 		"id": "0001",
 		"batters": map[string]any{
 			"batter": []any{
@@ -927,27 +808,10 @@ func TestAllKeys(t *testing.T) {
 			"snowboarding",
 			"go",
 		},
-		"age":    35,
-		"type":   "donut",
-		"newkey": "remote",
-		"name":   "Cake",
-		"p_id":   "0001",
-		"p_ppu":  "0.55",
-		"p_name": "Cake",
-		"p_batters": map[string]any{
-			"batter": map[string]any{"type": "Regular"},
-		},
-		"p_type": "donut",
-		"foos": []map[string]any{
-			{
-				"foo": []map[string]any{
-					{"key": 1},
-					{"key": 2},
-					{"key": 3},
-					{"key": 4},
-				},
-			},
-		},
+		"age":          35,
+		"type":         "donut",
+		"newkey":       "remote",
+		"name":         "Cake",
 		"title_dotenv": "DotEnv Example",
 		"type_dotenv":  "donut",
 		"name_dotenv":  "Cake",
@@ -1611,24 +1475,6 @@ func TestFindsNestedKeys(t *testing.T) {
 		"clothing.trousers":   "denim",
 		"owner.dob":           dob,
 		"beard":               true,
-		"foos": []map[string]any{
-			{
-				"foo": []map[string]any{
-					{
-						"key": 1,
-					},
-					{
-						"key": 2,
-					},
-					{
-						"key": 3,
-					},
-					{
-						"key": 4,
-					},
-				},
-			},
-		},
 	}
 
 	for key, expectedValue := range expected {
@@ -1800,32 +1646,6 @@ func TestSub(t *testing.T) {
 	assert.Equal(t, []string{"clothing", "pants"}, subv.parents)
 }
 
-var hclWriteExpected = []byte(`"foos" = {
-  "foo" = {
-    "key" = 1
-  }
-
-  "foo" = {
-    "key" = 2
-  }
-
-  "foo" = {
-    "key" = 3
-  }
-
-  "foo" = {
-    "key" = 4
-  }
-}
-
-"id" = "0001"
-
-"name" = "Cake"
-
-"ppu" = 0.55
-
-"type" = "donut"`)
-
 var jsonWriteExpected = []byte(`{
   "batters": {
     "batter": [
@@ -1849,13 +1669,6 @@ var jsonWriteExpected = []byte(`{
   "type": "donut"
 }`)
 
-var propertiesWriteExpected = []byte(`p_id = 0001
-p_type = donut
-p_name = Cake
-p_ppu = 0.55
-p_batters.batter.type = Regular
-`)
-
 // var yamlWriteExpected = []byte(`age: 35
 // beard: true
 // clothing:
@@ -1882,30 +1695,6 @@ func TestWriteConfig(t *testing.T) {
 		input           []byte
 		expectedContent []byte
 	}{
-		"hcl with file extension": {
-			configName:      "c",
-			inConfigType:    "hcl",
-			outConfigType:   "hcl",
-			fileName:        "c.hcl",
-			input:           hclExample,
-			expectedContent: hclWriteExpected,
-		},
-		"hcl without file extension": {
-			configName:      "c",
-			inConfigType:    "hcl",
-			outConfigType:   "hcl",
-			fileName:        "c",
-			input:           hclExample,
-			expectedContent: hclWriteExpected,
-		},
-		"hcl with file extension and mismatch type": {
-			configName:      "c",
-			inConfigType:    "hcl",
-			outConfigType:   "json",
-			fileName:        "c.hcl",
-			input:           hclExample,
-			expectedContent: hclWriteExpected,
-		},
 		"json with file extension": {
 			configName:      "c",
 			inConfigType:    "json",
@@ -1930,22 +1719,6 @@ func TestWriteConfig(t *testing.T) {
 			input:           jsonExample,
 			expectedContent: jsonWriteExpected,
 		},
-		"properties with file extension": {
-			configName:      "c",
-			inConfigType:    "properties",
-			outConfigType:   "properties",
-			fileName:        "c.properties",
-			input:           propertiesExample,
-			expectedContent: propertiesWriteExpected,
-		},
-		"properties without file extension": {
-			configName:      "c",
-			inConfigType:    "properties",
-			outConfigType:   "properties",
-			fileName:        "c",
-			input:           propertiesExample,
-			expectedContent: propertiesWriteExpected,
-		},
 		"yaml with file extension": {
 			configName:      "c",
 			inConfigType:    "yaml",