Bump viper version, fix nobrowser (#1991)

vendor/github.com/spf13/viper/viper.go

@@ -22,7 +22,6 @@ package viper
 import (
 	"bytes"
 	"encoding/csv"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -30,23 +29,26 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/fsnotify/fsnotify"
-	"github.com/hashicorp/hcl"
-	"github.com/hashicorp/hcl/hcl/printer"
 	"github.com/magiconair/properties"
 	"github.com/mitchellh/mapstructure"
-	"github.com/pelletier/go-toml"
 	"github.com/spf13/afero"
 	"github.com/spf13/cast"
 	jww "github.com/spf13/jwalterweatherman"
 	"github.com/spf13/pflag"
 	"github.com/subosito/gotenv"
 	"gopkg.in/ini.v1"
-	"gopkg.in/yaml.v2"
+
+	"github.com/spf13/viper/internal/encoding"
+	"github.com/spf13/viper/internal/encoding/hcl"
+	"github.com/spf13/viper/internal/encoding/json"
+	"github.com/spf13/viper/internal/encoding/toml"
+	"github.com/spf13/viper/internal/encoding/yaml"
 )
 
 // ConfigMarshalError happens when failing to marshal the configuration.
@@ -66,8 +68,47 @@ type RemoteResponse struct {
 	Error error
 }
 
+var (
+	encoderRegistry = encoding.NewEncoderRegistry()
+	decoderRegistry = encoding.NewDecoderRegistry()
+)
+
 func init() {
 	v = New()
+
+	{
+		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)
+	}
 }
 
 type remoteConfigFactory interface {
@@ -175,6 +216,8 @@ func DecodeHook(hook mapstructure.DecodeHookFunc) DecoderConfigOption {
 //		"user": "root",
 //		"endpoint": "https://localhost"
 //	}
+//
+// Note: Vipers are not safe for concurrent Get() and Set() operations.
 type Viper struct {
 	// Delimiter that separates a list of keys
 	// used to access a nested value in one go
@@ -196,6 +239,9 @@ type Viper struct {
 	configPermissions os.FileMode
 	envPrefix         string
 
+	// Specific commands for ini parsing
+	iniLoadOptions ini.LoadOptions
+
 	automaticEnvApplied bool
 	envKeyReplacer      StringReplacer
 	allowEmptyEnv       bool
@@ -205,7 +251,7 @@ type Viper struct {
 	defaults       map[string]interface{}
 	kvstore        map[string]interface{}
 	pflags         map[string]FlagValue
-	env            map[string]string
+	env            map[string][]string
 	aliases        map[string]string
 	typeByDefValue bool
 
@@ -228,7 +274,7 @@ func New() *Viper {
 	v.defaults = make(map[string]interface{})
 	v.kvstore = make(map[string]interface{})
 	v.pflags = make(map[string]FlagValue)
-	v.env = make(map[string]string)
+	v.env = make(map[string][]string)
 	v.aliases = make(map[string]string)
 	v.typeByDefValue = false
 
@@ -286,7 +332,7 @@ func NewWithOptions(opts ...Option) *Viper {
 // can use it in their testing as well.
 func Reset() {
 	v = New()
-	SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "dotenv", "env", "ini"}
+	SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "tfvars", "dotenv", "env", "ini"}
 	SupportedRemoteProviders = []string{"etcd", "consul", "firestore"}
 }
 
@@ -325,7 +371,7 @@ type RemoteProvider interface {
 }
 
 // SupportedExts are universally supported extensions.
-var SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "dotenv", "env", "ini"}
+var SupportedExts = []string{"json", "toml", "yaml", "yml", "properties", "props", "prop", "hcl", "tfvars", "dotenv", "env", "ini"}
 
 // SupportedRemoteProviders are universally supported remote providers.
 var SupportedRemoteProviders = []string{"etcd", "consul", "firestore"}
@@ -341,7 +387,7 @@ func (v *Viper) WatchConfig() {
 	initWG := sync.WaitGroup{}
 	initWG.Add(1)
 	go func() {
-		watcher, err := fsnotify.NewWatcher()
+		watcher, err := newWatcher()
 		if err != nil {
 			log.Fatal(err)
 		}
@@ -409,6 +455,7 @@ func (v *Viper) WatchConfig() {
 // SetConfigFile explicitly defines the path, name and extension of the config file.
 // Viper will use this and not check any of the config paths.
 func SetConfigFile(in string) { v.SetConfigFile(in) }
+
 func (v *Viper) SetConfigFile(in string) {
 	if in != "" {
 		v.configFile = in
@@ -419,6 +466,7 @@ func (v *Viper) SetConfigFile(in string) {
 // E.g. if your prefix is "spf", the env registry will look for env
 // variables that start with "SPF_".
 func SetEnvPrefix(in string) { v.SetEnvPrefix(in) }
+
 func (v *Viper) SetEnvPrefix(in string) {
 	if in != "" {
 		v.envPrefix = in
@@ -437,6 +485,7 @@ func (v *Viper) mergeWithEnvPrefix(in string) string {
 // but empty environment variables as valid values instead of falling back.
 // For backward compatibility reasons this is false by default.
 func AllowEmptyEnv(allowEmptyEnv bool) { v.AllowEmptyEnv(allowEmptyEnv) }
+
 func (v *Viper) AllowEmptyEnv(allowEmptyEnv bool) {
 	v.allowEmptyEnv = allowEmptyEnv
 }
@@ -465,6 +514,7 @@ func (v *Viper) ConfigFileUsed() string { return v.configFile }
 // AddConfigPath adds a path for Viper to search for the config file in.
 // Can be called multiple times to define multiple search paths.
 func AddConfigPath(in string) { v.AddConfigPath(in) }
+
 func (v *Viper) AddConfigPath(in string) {
 	if in != "" {
 		absin := absPathify(in)
@@ -486,6 +536,7 @@ func (v *Viper) AddConfigPath(in string) {
 func AddRemoteProvider(provider, endpoint, path string) error {
 	return v.AddRemoteProvider(provider, endpoint, path)
 }
+
 func (v *Viper) AddRemoteProvider(provider, endpoint, path string) error {
 	if !stringInSlice(provider, SupportedRemoteProviders) {
 		return UnsupportedRemoteProviderError(provider)
@@ -577,9 +628,9 @@ func (v *Viper) searchMap(source map[string]interface{}, path []string) interfac
 	return nil
 }
 
-// searchMapWithPathPrefixes recursively searches for a value for path in source map.
+// searchIndexableWithPathPrefixes recursively searches for a value for path in source map/slice.
 //
-// While searchMap() considers each path element as a single map key, this
+// While searchMap() considers each path element as a single map key or slice index, this
 // function searches for, and prioritizes, merged path elements.
 // e.g., if in the source, "foo" is defined with a sub-key "bar", and "foo.bar"
 // is also defined, this latter value is returned for path ["foo", "bar"].
@@ -588,7 +639,7 @@ func (v *Viper) searchMap(source map[string]interface{}, path []string) interfac
 // in their keys).
 //
 // Note: This assumes that the path entries and map keys are lower cased.
-func (v *Viper) searchMapWithPathPrefixes(source map[string]interface{}, path []string) interface{} {
+func (v *Viper) searchIndexableWithPathPrefixes(source interface{}, path []string) interface{} {
 	if len(path) == 0 {
 		return source
 	}
@@ -597,29 +648,86 @@ func (v *Viper) searchMapWithPathPrefixes(source map[string]interface{}, path []
 	for i := len(path); i > 0; i-- {
 		prefixKey := strings.ToLower(strings.Join(path[0:i], v.keyDelim))
 
-		next, ok := source[prefixKey]
-		if ok {
-			// Fast path
-			if i == len(path) {
-				return next
-			}
-
-			// Nested case
-			var val interface{}
-			switch next.(type) {
-			case map[interface{}]interface{}:
-				val = v.searchMapWithPathPrefixes(cast.ToStringMap(next), path[i:])
-			case map[string]interface{}:
-				// Type assertion is safe here since it is only reached
-				// if the type of `next` is the same as the type being asserted
-				val = v.searchMapWithPathPrefixes(next.(map[string]interface{}), path[i:])
-			default:
-				// got a value but nested key expected, do nothing and look for next prefix
-			}
-			if val != nil {
-				return val
-			}
+		var val interface{}
+		switch sourceIndexable := source.(type) {
+		case []interface{}:
+			val = v.searchSliceWithPathPrefixes(sourceIndexable, prefixKey, i, path)
+		case map[string]interface{}:
+			val = v.searchMapWithPathPrefixes(sourceIndexable, prefixKey, i, path)
 		}
+		if val != nil {
+			return val
+		}
+	}
+
+	// not found
+	return nil
+}
+
+// searchSliceWithPathPrefixes searches for a value for path in sourceSlice
+//
+// This function is part of the searchIndexableWithPathPrefixes recurring search and
+// should not be called directly from functions other than searchIndexableWithPathPrefixes.
+func (v *Viper) searchSliceWithPathPrefixes(
+	sourceSlice []interface{},
+	prefixKey string,
+	pathIndex int,
+	path []string,
+) interface{} {
+	// if the prefixKey is not a number or it is out of bounds of the slice
+	index, err := strconv.Atoi(prefixKey)
+	if err != nil || len(sourceSlice) <= index {
+		return nil
+	}
+
+	next := sourceSlice[index]
+
+	// Fast path
+	if pathIndex == len(path) {
+		return next
+	}
+
+	switch n := next.(type) {
+	case map[interface{}]interface{}:
+		return v.searchIndexableWithPathPrefixes(cast.ToStringMap(n), path[pathIndex:])
+	case map[string]interface{}, []interface{}:
+		return v.searchIndexableWithPathPrefixes(n, path[pathIndex:])
+	default:
+		// got a value but nested key expected, do nothing and look for next prefix
+	}
+
+	// not found
+	return nil
+}
+
+// searchMapWithPathPrefixes searches for a value for path in sourceMap
+//
+// This function is part of the searchIndexableWithPathPrefixes recurring search and
+// should not be called directly from functions other than searchIndexableWithPathPrefixes.
+func (v *Viper) searchMapWithPathPrefixes(
+	sourceMap map[string]interface{},
+	prefixKey string,
+	pathIndex int,
+	path []string,
+) interface{} {
+	next, ok := sourceMap[prefixKey]
+	if !ok {
+		return nil
+	}
+
+	// Fast path
+	if pathIndex == len(path) {
+		return next
+	}
+
+	// Nested case
+	switch n := next.(type) {
+	case map[interface{}]interface{}:
+		return v.searchIndexableWithPathPrefixes(cast.ToStringMap(n), path[pathIndex:])
+	case map[string]interface{}, []interface{}:
+		return v.searchIndexableWithPathPrefixes(n, path[pathIndex:])
+	default:
+		// got a value but nested key expected, do nothing and look for next prefix
 	}
 
 	// not found
@@ -706,6 +814,7 @@ func (v *Viper) isPathShadowedInAutoEnv(path []string) string {
 //
 //   "a b c"
 func SetTypeByDefaultValue(enable bool) { v.SetTypeByDefaultValue(enable) }
+
 func (v *Viper) SetTypeByDefaultValue(enable bool) {
 	v.typeByDefValue = enable
 }
@@ -723,6 +832,7 @@ func GetViper() *Viper {
 //
 // Get returns an interface. For a specific value use one of the Get____ methods.
 func Get(key string) interface{} { return v.Get(key) }
+
 func (v *Viper) Get(key string) interface{} {
 	lcaseKey := strings.ToLower(key)
 	val := v.find(lcaseKey, true)
@@ -773,6 +883,7 @@ func (v *Viper) Get(key string) interface{} {
 // Sub returns new Viper instance representing a sub tree of this instance.
 // Sub is case-insensitive for a key.
 func Sub(key string) *Viper { return v.Sub(key) }
+
 func (v *Viper) Sub(key string) *Viper {
 	subv := New()
 	data := v.Get(key)
@@ -789,96 +900,112 @@ func (v *Viper) Sub(key string) *Viper {
 
 // GetString returns the value associated with the key as a string.
 func GetString(key string) string { return v.GetString(key) }
+
 func (v *Viper) GetString(key string) string {
 	return cast.ToString(v.Get(key))
 }
 
 // GetBool returns the value associated with the key as a boolean.
 func GetBool(key string) bool { return v.GetBool(key) }
+
 func (v *Viper) GetBool(key string) bool {
 	return cast.ToBool(v.Get(key))
 }
 
 // GetInt returns the value associated with the key as an integer.
 func GetInt(key string) int { return v.GetInt(key) }
+
 func (v *Viper) GetInt(key string) int {
 	return cast.ToInt(v.Get(key))
 }
 
 // GetInt32 returns the value associated with the key as an integer.
 func GetInt32(key string) int32 { return v.GetInt32(key) }
+
 func (v *Viper) GetInt32(key string) int32 {
 	return cast.ToInt32(v.Get(key))
 }
 
 // GetInt64 returns the value associated with the key as an integer.
 func GetInt64(key string) int64 { return v.GetInt64(key) }
+
 func (v *Viper) GetInt64(key string) int64 {
 	return cast.ToInt64(v.Get(key))
 }
 
 // GetUint returns the value associated with the key as an unsigned integer.
 func GetUint(key string) uint { return v.GetUint(key) }
+
 func (v *Viper) GetUint(key string) uint {
 	return cast.ToUint(v.Get(key))
 }
 
 // GetUint32 returns the value associated with the key as an unsigned integer.
 func GetUint32(key string) uint32 { return v.GetUint32(key) }
+
 func (v *Viper) GetUint32(key string) uint32 {
 	return cast.ToUint32(v.Get(key))
 }
 
 // GetUint64 returns the value associated with the key as an unsigned integer.
 func GetUint64(key string) uint64 { return v.GetUint64(key) }
+
 func (v *Viper) GetUint64(key string) uint64 {
 	return cast.ToUint64(v.Get(key))
 }
 
 // GetFloat64 returns the value associated with the key as a float64.
 func GetFloat64(key string) float64 { return v.GetFloat64(key) }
+
 func (v *Viper) GetFloat64(key string) float64 {
 	return cast.ToFloat64(v.Get(key))
 }
 
 // GetTime returns the value associated with the key as time.
 func GetTime(key string) time.Time { return v.GetTime(key) }
+
 func (v *Viper) GetTime(key string) time.Time {
 	return cast.ToTime(v.Get(key))
 }
 
 // GetDuration returns the value associated with the key as a duration.
 func GetDuration(key string) time.Duration { return v.GetDuration(key) }
+
 func (v *Viper) GetDuration(key string) time.Duration {
 	return cast.ToDuration(v.Get(key))
 }
 
 // GetIntSlice returns the value associated with the key as a slice of int values.
 func GetIntSlice(key string) []int { return v.GetIntSlice(key) }
+
 func (v *Viper) GetIntSlice(key string) []int {
 	return cast.ToIntSlice(v.Get(key))
 }
 
 // GetStringSlice returns the value associated with the key as a slice of strings.
 func GetStringSlice(key string) []string { return v.GetStringSlice(key) }
+
 func (v *Viper) GetStringSlice(key string) []string {
 	return cast.ToStringSlice(v.Get(key))
 }
 
 // GetStringMap returns the value associated with the key as a map of interfaces.
 func GetStringMap(key string) map[string]interface{} { return v.GetStringMap(key) }
+
 func (v *Viper) GetStringMap(key string) map[string]interface{} {
 	return cast.ToStringMap(v.Get(key))
 }
 
 // GetStringMapString returns the value associated with the key as a map of strings.
 func GetStringMapString(key string) map[string]string { return v.GetStringMapString(key) }
+
 func (v *Viper) GetStringMapString(key string) map[string]string {
 	return cast.ToStringMapString(v.Get(key))
 }
 
 // GetStringMapStringSlice returns the value associated with the key as a map to a slice of strings.
 func GetStringMapStringSlice(key string) map[string][]string { return v.GetStringMapStringSlice(key) }
+
 func (v *Viper) GetStringMapStringSlice(key string) map[string][]string {
 	return cast.ToStringMapStringSlice(v.Get(key))
 }
@@ -886,6 +1013,7 @@ func (v *Viper) GetStringMapStringSlice(key string) map[string][]string {
 // GetSizeInBytes returns the size of the value associated with the given key
 // in bytes.
 func GetSizeInBytes(key string) uint { return v.GetSizeInBytes(key) }
+
 func (v *Viper) GetSizeInBytes(key string) uint {
 	sizeStr := cast.ToString(v.Get(key))
 	return parseSizeInBytes(sizeStr)
@@ -895,14 +1023,9 @@ func (v *Viper) GetSizeInBytes(key string) uint {
 func UnmarshalKey(key string, rawVal interface{}, opts ...DecoderConfigOption) error {
 	return v.UnmarshalKey(key, rawVal, opts...)
 }
+
 func (v *Viper) UnmarshalKey(key string, rawVal interface{}, opts ...DecoderConfigOption) error {
-	err := decode(v.Get(key), defaultDecoderConfig(rawVal, opts...))
-
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return decode(v.Get(key), defaultDecoderConfig(rawVal, opts...))
 }
 
 // Unmarshal unmarshals the config into a Struct. Make sure that the tags
@@ -910,14 +1033,9 @@ func (v *Viper) UnmarshalKey(key string, rawVal interface{}, opts ...DecoderConf
 func Unmarshal(rawVal interface{}, opts ...DecoderConfigOption) error {
 	return v.Unmarshal(rawVal, opts...)
 }
+
 func (v *Viper) Unmarshal(rawVal interface{}, opts ...DecoderConfigOption) error {
-	err := decode(v.AllSettings(), defaultDecoderConfig(rawVal, opts...))
-
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return decode(v.AllSettings(), defaultDecoderConfig(rawVal, opts...))
 }
 
 // defaultDecoderConfig returns default mapsstructure.DecoderConfig with suppot
@@ -952,22 +1070,18 @@ func decode(input interface{}, config *mapstructure.DecoderConfig) error {
 func UnmarshalExact(rawVal interface{}, opts ...DecoderConfigOption) error {
 	return v.UnmarshalExact(rawVal, opts...)
 }
+
 func (v *Viper) UnmarshalExact(rawVal interface{}, opts ...DecoderConfigOption) error {
 	config := defaultDecoderConfig(rawVal, opts...)
 	config.ErrorUnused = true
 
-	err := decode(v.AllSettings(), config)
-
-	if err != nil {
-		return err
-	}
-
-	return nil
+	return decode(v.AllSettings(), config)
 }
 
 // BindPFlags binds a full flag set to the configuration, using each flag's long
 // name as the config key.
 func BindPFlags(flags *pflag.FlagSet) error { return v.BindPFlags(flags) }
+
 func (v *Viper) BindPFlags(flags *pflag.FlagSet) error {
 	return v.BindFlagValues(pflagValueSet{flags})
 }
@@ -979,13 +1093,18 @@ func (v *Viper) BindPFlags(flags *pflag.FlagSet) error {
 //	 Viper.BindPFlag("port", serverCmd.Flags().Lookup("port"))
 //
 func BindPFlag(key string, flag *pflag.Flag) error { return v.BindPFlag(key, flag) }
+
 func (v *Viper) BindPFlag(key string, flag *pflag.Flag) error {
+	if flag == nil {
+		return fmt.Errorf("flag for %q is nil", key)
+	}
 	return v.BindFlagValue(key, pflagValue{flag})
 }
 
 // BindFlagValues binds a full FlagValue set to the configuration, using each flag's long
 // name as the config key.
 func BindFlagValues(flags FlagValueSet) error { return v.BindFlagValues(flags) }
+
 func (v *Viper) BindFlagValues(flags FlagValueSet) (err error) {
 	flags.VisitAll(func(flag FlagValue) {
 		if err = v.BindFlagValue(flag.Name(), flag); err != nil {
@@ -997,6 +1116,7 @@ func (v *Viper) BindFlagValues(flags FlagValueSet) (err error) {
 
 // BindFlagValue binds a specific key to a FlagValue.
 func BindFlagValue(key string, flag FlagValue) error { return v.BindFlagValue(key, flag) }
+
 func (v *Viper) BindFlagValue(key string, flag FlagValue) error {
 	if flag == nil {
 		return fmt.Errorf("flag for %q is nil", key)
@@ -1008,24 +1128,24 @@ func (v *Viper) BindFlagValue(key string, flag FlagValue) error {
 // BindEnv binds a Viper key to a ENV variable.
 // ENV variables are case sensitive.
 // If only a key is provided, it will use the env key matching the key, uppercased.
+// If more arguments are provided, they will represent the env variable names that
+// should bind to this key and will be taken in the specified order.
 // EnvPrefix will be used when set when env name is not provided.
 func BindEnv(input ...string) error { return v.BindEnv(input...) }
+
 func (v *Viper) BindEnv(input ...string) error {
-	var key, envkey string
 	if len(input) == 0 {
 		return fmt.Errorf("missing key to bind to")
 	}
 
-	key = strings.ToLower(input[0])
+	key := strings.ToLower(input[0])
 
 	if len(input) == 1 {
-		envkey = v.mergeWithEnvPrefix(key)
+		v.env[key] = append(v.env[key], v.mergeWithEnvPrefix(key))
 	} else {
-		envkey = input[1]
+		v.env[key] = append(v.env[key], input[1:]...)
 	}
 
-	v.env[key] = envkey
-
 	return nil
 }
 
@@ -1073,7 +1193,7 @@ func (v *Viper) find(lcaseKey string, flagDefault bool) interface{} {
 			return cast.ToInt(flag.ValueString())
 		case "bool":
 			return cast.ToBool(flag.ValueString())
-		case "stringSlice":
+		case "stringSlice", "stringArray":
 			s := strings.TrimPrefix(flag.ValueString(), "[")
 			s = strings.TrimSuffix(s, "]")
 			res, _ := readAsCSV(s)
@@ -1104,10 +1224,12 @@ func (v *Viper) find(lcaseKey string, flagDefault bool) interface{} {
 			return nil
 		}
 	}
-	envkey, exists := v.env[lcaseKey]
+	envkeys, exists := v.env[lcaseKey]
 	if exists {
-		if val, ok := v.getEnv(envkey); ok {
-			return val
+		for _, envkey := range envkeys {
+			if val, ok := v.getEnv(envkey); ok {
+				return val
+			}
 		}
 	}
 	if nested && v.isPathShadowedInFlatMap(path, v.env) != "" {
@@ -1115,7 +1237,7 @@ func (v *Viper) find(lcaseKey string, flagDefault bool) interface{} {
 	}
 
 	// Config file next
-	val = v.searchMapWithPathPrefixes(v.config, path)
+	val = v.searchIndexableWithPathPrefixes(v.config, path)
 	if val != nil {
 		return val
 	}
@@ -1150,7 +1272,7 @@ func (v *Viper) find(lcaseKey string, flagDefault bool) interface{} {
 				return cast.ToInt(flag.ValueString())
 			case "bool":
 				return cast.ToBool(flag.ValueString())
-			case "stringSlice":
+			case "stringSlice", "stringArray":
 				s := strings.TrimPrefix(flag.ValueString(), "[")
 				s = strings.TrimSuffix(s, "]")
 				res, _ := readAsCSV(s)
@@ -1208,15 +1330,17 @@ func stringToStringConv(val string) interface{} {
 // IsSet checks to see if the key has been set in any of the data locations.
 // IsSet is case-insensitive for a key.
 func IsSet(key string) bool { return v.IsSet(key) }
+
 func (v *Viper) IsSet(key string) bool {
 	lcaseKey := strings.ToLower(key)
 	val := v.find(lcaseKey, false)
 	return val != nil
 }
 
-// AutomaticEnv has Viper check ENV variables for all.
-// keys set in config, default & flags
+// AutomaticEnv makes Viper check if environment variables match any of the existing keys
+// (config, default or flags). If matching env vars are found, they are loaded into Viper.
 func AutomaticEnv() { v.AutomaticEnv() }
+
 func (v *Viper) AutomaticEnv() {
 	v.automaticEnvApplied = true
 }
@@ -1225,6 +1349,7 @@ func (v *Viper) AutomaticEnv() {
 // Useful for mapping an environmental variable to a key that does
 // not match it.
 func SetEnvKeyReplacer(r *strings.Replacer) { v.SetEnvKeyReplacer(r) }
+
 func (v *Viper) SetEnvKeyReplacer(r *strings.Replacer) {
 	v.envKeyReplacer = r
 }
@@ -1232,6 +1357,7 @@ func (v *Viper) SetEnvKeyReplacer(r *strings.Replacer) {
 // RegisterAlias creates an alias that provides another accessor for the same key.
 // This enables one to change a name without breaking the application.
 func RegisterAlias(alias string, key string) { v.RegisterAlias(alias, key) }
+
 func (v *Viper) RegisterAlias(alias string, key string) {
 	v.registerAlias(alias, strings.ToLower(key))
 }
@@ -1279,18 +1405,22 @@ func (v *Viper) realKey(key string) string {
 
 // InConfig checks to see if the given key (or an alias) is in the config file.
 func InConfig(key string) bool { return v.InConfig(key) }
-func (v *Viper) InConfig(key string) bool {
-	// if the requested key is an alias, then return the proper key
-	key = v.realKey(key)
 
-	_, exists := v.config[key]
-	return exists
+func (v *Viper) InConfig(key string) bool {
+	lcaseKey := strings.ToLower(key)
+
+	// if the requested key is an alias, then return the proper key
+	lcaseKey = v.realKey(lcaseKey)
+	path := strings.Split(lcaseKey, v.keyDelim)
+
+	return v.searchIndexableWithPathPrefixes(v.config, path) != nil
 }
 
 // SetDefault sets the default value for this key.
 // SetDefault is case-insensitive for a key.
 // Default only used when no value is provided by the user via flag, config or ENV.
 func SetDefault(key string, value interface{}) { v.SetDefault(key, value) }
+
 func (v *Viper) SetDefault(key string, value interface{}) {
 	// If alias passed in, then set the proper default
 	key = v.realKey(strings.ToLower(key))
@@ -1309,6 +1439,7 @@ func (v *Viper) SetDefault(key string, value interface{}) {
 // Will be used instead of values obtained via
 // flags, config file, ENV, default, or key/value store.
 func Set(key string, value interface{}) { v.Set(key, value) }
+
 func (v *Viper) Set(key string, value interface{}) {
 	// If alias passed in, then set the proper override
 	key = v.realKey(strings.ToLower(key))
@@ -1325,6 +1456,7 @@ func (v *Viper) Set(key string, value interface{}) {
 // ReadInConfig will discover and load the configuration file from disk
 // and key/value stores, searching in one of the defined paths.
 func ReadInConfig() error { return v.ReadInConfig() }
+
 func (v *Viper) ReadInConfig() error {
 	jww.INFO.Println("Attempting to read in config file")
 	filename, err := v.getConfigFile()
@@ -1355,6 +1487,7 @@ func (v *Viper) ReadInConfig() error {
 
 // MergeInConfig merges a new configuration with an existing config.
 func MergeInConfig() error { return v.MergeInConfig() }
+
 func (v *Viper) MergeInConfig() error {
 	jww.INFO.Println("Attempting to merge in config file")
 	filename, err := v.getConfigFile()
@@ -1377,6 +1510,7 @@ func (v *Viper) MergeInConfig() error {
 // ReadConfig will read a configuration file, setting existing keys to nil if the
 // key does not exist in the file.
 func ReadConfig(in io.Reader) error { return v.ReadConfig(in) }
+
 func (v *Viper) ReadConfig(in io.Reader) error {
 	v.config = make(map[string]interface{})
 	return v.unmarshalReader(in, v.config)
@@ -1384,6 +1518,7 @@ func (v *Viper) ReadConfig(in io.Reader) error {
 
 // MergeConfig merges a new configuration with an existing config.
 func MergeConfig(in io.Reader) error { return v.MergeConfig(in) }
+
 func (v *Viper) MergeConfig(in io.Reader) error {
 	cfg := make(map[string]interface{})
 	if err := v.unmarshalReader(in, cfg); err != nil {
@@ -1395,6 +1530,7 @@ func (v *Viper) MergeConfig(in io.Reader) error {
 // MergeConfigMap merges the configuration from the map given with an existing config.
 // Note that the map given may be modified.
 func MergeConfigMap(cfg map[string]interface{}) error { return v.MergeConfigMap(cfg) }
+
 func (v *Viper) MergeConfigMap(cfg map[string]interface{}) error {
 	if v.config == nil {
 		v.config = make(map[string]interface{})
@@ -1406,6 +1542,7 @@ func (v *Viper) MergeConfigMap(cfg map[string]interface{}) error {
 
 // WriteConfig writes the current configuration to a file.
 func WriteConfig() error { return v.WriteConfig() }
+
 func (v *Viper) WriteConfig() error {
 	filename, err := v.getConfigFile()
 	if err != nil {
@@ -1416,6 +1553,7 @@ func (v *Viper) WriteConfig() error {
 
 // SafeWriteConfig writes current configuration to file only if the file does not exist.
 func SafeWriteConfig() error { return v.SafeWriteConfig() }
+
 func (v *Viper) SafeWriteConfig() error {
 	if len(v.configPaths) < 1 {
 		return errors.New("missing configuration for 'configPath'")
@@ -1425,12 +1563,14 @@ func (v *Viper) SafeWriteConfig() error {
 
 // WriteConfigAs writes current configuration to a given filename.
 func WriteConfigAs(filename string) error { return v.WriteConfigAs(filename) }
+
 func (v *Viper) WriteConfigAs(filename string) error {
 	return v.writeConfig(filename, true)
 }
 
 // SafeWriteConfigAs writes current configuration to a given filename if it does not exist.
 func SafeWriteConfigAs(filename string) error { return v.SafeWriteConfigAs(filename) }
+
 func (v *Viper) SafeWriteConfigAs(filename string) error {
 	alreadyExists, err := afero.Exists(v.fs, filename)
 	if alreadyExists && err == nil {
@@ -1444,7 +1584,7 @@ func (v *Viper) writeConfig(filename string, force bool) error {
 	var configType string
 
 	ext := filepath.Ext(filename)
-	if ext != "" {
+	if ext != "" && ext != filepath.Base(filename) {
 		configType = ext[1:]
 	} else {
 		configType = v.configType
@@ -1481,39 +1621,17 @@ func (v *Viper) writeConfig(filename string, force bool) error {
 func unmarshalReader(in io.Reader, c map[string]interface{}) error {
 	return v.unmarshalReader(in, c)
 }
+
 func (v *Viper) unmarshalReader(in io.Reader, c map[string]interface{}) error {
 	buf := new(bytes.Buffer)
 	buf.ReadFrom(in)
 
-	switch strings.ToLower(v.getConfigType()) {
-	case "yaml", "yml":
-		if err := yaml.Unmarshal(buf.Bytes(), &c); err != nil {
-			return ConfigParseError{err}
-		}
-
-	case "json":
-		if err := json.Unmarshal(buf.Bytes(), &c); err != nil {
-			return ConfigParseError{err}
-		}
-
-	case "hcl":
-		obj, err := hcl.Parse(buf.String())
+	switch format := strings.ToLower(v.getConfigType()); format {
+	case "yaml", "yml", "json", "toml", "hcl", "tfvars":
+		err := decoderRegistry.Decode(format, buf.Bytes(), &c)
 		if err != nil {
 			return ConfigParseError{err}
 		}
-		if err = hcl.DecodeObject(&c, obj); err != nil {
-			return ConfigParseError{err}
-		}
-
-	case "toml":
-		tree, err := toml.LoadReader(buf)
-		if err != nil {
-			return ConfigParseError{err}
-		}
-		tmap := tree.ToMap()
-		for k, v := range tmap {
-			c[k] = v
-		}
 
 	case "dotenv", "env":
 		env, err := gotenv.StrictParse(buf)
@@ -1541,7 +1659,7 @@ func (v *Viper) unmarshalReader(in io.Reader, c map[string]interface{}) error {
 		}
 
 	case "ini":
-		cfg := ini.Empty()
+		cfg := ini.Empty(v.iniLoadOptions)
 		err := cfg.Append(buf.Bytes())
 		if err != nil {
 			return ConfigParseError{err}
@@ -1566,26 +1684,13 @@ func (v *Viper) unmarshalReader(in io.Reader, c map[string]interface{}) error {
 func (v *Viper) marshalWriter(f afero.File, configType string) error {
 	c := v.AllSettings()
 	switch configType {
-	case "json":
-		b, err := json.MarshalIndent(c, "", "  ")
-		if err != nil {
-			return ConfigMarshalError{err}
-		}
-		_, err = f.WriteString(string(b))
+	case "yaml", "yml", "json", "toml", "hcl", "tfvars":
+		b, err := encoderRegistry.Encode(configType, c)
 		if err != nil {
 			return ConfigMarshalError{err}
 		}
 
-	case "hcl":
-		b, err := json.Marshal(c)
-		if err != nil {
-			return ConfigMarshalError{err}
-		}
-		ast, err := hcl.Parse(string(b))
-		if err != nil {
-			return ConfigMarshalError{err}
-		}
-		err = printer.Fprint(f, ast.Node)
+		_, err = f.WriteString(string(b))
 		if err != nil {
 			return ConfigMarshalError{err}
 		}
@@ -1618,25 +1723,6 @@ func (v *Viper) marshalWriter(f afero.File, configType string) error {
 			return ConfigMarshalError{err}
 		}
 
-	case "toml":
-		t, err := toml.TreeFromMap(c)
-		if err != nil {
-			return ConfigMarshalError{err}
-		}
-		s := t.String()
-		if _, err := f.WriteString(s); err != nil {
-			return ConfigMarshalError{err}
-		}
-
-	case "yaml", "yml":
-		b, err := yaml.Marshal(c)
-		if err != nil {
-			return ConfigMarshalError{err}
-		}
-		if _, err = f.WriteString(string(b)); err != nil {
-			return ConfigMarshalError{err}
-		}
-
 	case "ini":
 		keys := v.AllKeys()
 		cfg := ini.Empty()
@@ -1649,7 +1735,7 @@ func (v *Viper) marshalWriter(f afero.File, configType string) error {
 			if sectionName == "default" {
 				sectionName = ""
 			}
-			cfg.Section(sectionName).Key(keyName).SetValue(v.Get(key).(string))
+			cfg.Section(sectionName).Key(keyName).SetValue(v.GetString(key))
 		}
 		cfg.WriteTo(f)
 	}
@@ -1676,6 +1762,14 @@ func castToMapStringInterface(
 	return tgt
 }
 
+func castMapStringSliceToMapInterface(src map[string][]string) map[string]interface{} {
+	tgt := map[string]interface{}{}
+	for k, v := range src {
+		tgt[k] = v
+	}
+	return tgt
+}
+
 func castMapStringToMapInterface(src map[string]string) map[string]interface{} {
 	tgt := map[string]interface{}{}
 	for k, v := range src {
@@ -1722,7 +1816,7 @@ func mergeMaps(
 
 		svType := reflect.TypeOf(sv)
 		tvType := reflect.TypeOf(tv)
-		if svType != tvType {
+		if tvType != nil && svType != tvType { // Allow for the target to be nil
 			jww.ERROR.Printf(
 				"svType != tvType; key=%s, st=%v, tt=%v, sv=%v, tv=%v",
 				sk, svType, tvType, sv, tv)
@@ -1755,6 +1849,7 @@ func mergeMaps(
 // ReadRemoteConfig attempts to get configuration from a remote source
 // and read it in the remote configuration registry.
 func ReadRemoteConfig() error { return v.ReadRemoteConfig() }
+
 func (v *Viper) ReadRemoteConfig() error {
 	return v.getKeyValueConfig()
 }
@@ -1777,9 +1872,13 @@ func (v *Viper) getKeyValueConfig() error {
 	for _, rp := range v.remoteProviders {
 		val, err := v.getRemoteConfig(rp)
 		if err != nil {
+			jww.ERROR.Printf("get remote config: %s", err)
+
 			continue
 		}
+
 		v.kvstore = val
+
 		return nil
 	}
 	return RemoteConfigError("No Files Found")
@@ -1836,13 +1935,14 @@ func (v *Viper) watchRemoteConfig(provider RemoteProvider) (map[string]interface
 // AllKeys returns all keys holding a value, regardless of where they are set.
 // Nested keys are returned with a v.keyDelim separator
 func AllKeys() []string { return v.AllKeys() }
+
 func (v *Viper) AllKeys() []string {
 	m := map[string]bool{}
 	// add all paths, by order of descending priority to ensure correct shadowing
 	m = v.flattenAndMergeMap(m, castMapStringToMapInterface(v.aliases), "")
 	m = v.flattenAndMergeMap(m, v.override, "")
 	m = v.mergeFlatMap(m, castMapFlagToMapInterface(v.pflags))
-	m = v.mergeFlatMap(m, castMapStringToMapInterface(v.env))
+	m = v.mergeFlatMap(m, castMapStringSliceToMapInterface(v.env))
 	m = v.flattenAndMergeMap(m, v.config, "")
 	m = v.flattenAndMergeMap(m, v.kvstore, "")
 	m = v.flattenAndMergeMap(m, v.defaults, "")
@@ -1916,6 +2016,7 @@ outer:
 
 // AllSettings merges all settings and returns them as a map[string]interface{}.
 func AllSettings() map[string]interface{} { return v.AllSettings() }
+
 func (v *Viper) AllSettings() map[string]interface{} {
 	m := map[string]interface{}{}
 	// start from the list of keys, and construct the map one value at a time
@@ -1937,6 +2038,7 @@ func (v *Viper) AllSettings() map[string]interface{} {
 
 // SetFs sets the filesystem to use to read configuration.
 func SetFs(fs afero.Fs) { v.SetFs(fs) }
+
 func (v *Viper) SetFs(fs afero.Fs) {
 	v.fs = fs
 }
@@ -1944,6 +2046,7 @@ func (v *Viper) SetFs(fs afero.Fs) {
 // SetConfigName sets name for the config file.
 // Does not include extension.
 func SetConfigName(in string) { v.SetConfigName(in) }
+
 func (v *Viper) SetConfigName(in string) {
 	if in != "" {
 		v.configName = in
@@ -1954,6 +2057,7 @@ func (v *Viper) SetConfigName(in string) {
 // SetConfigType sets the type of the configuration returned by the
 // remote source, e.g. "json".
 func SetConfigType(in string) { v.SetConfigType(in) }
+
 func (v *Viper) SetConfigType(in string) {
 	if in != "" {
 		v.configType = in
@@ -1962,10 +2066,18 @@ func (v *Viper) SetConfigType(in string) {
 
 // SetConfigPermissions sets the permissions for the config file.
 func SetConfigPermissions(perm os.FileMode) { v.SetConfigPermissions(perm) }
+
 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
@@ -2032,6 +2144,7 @@ func (v *Viper) findConfigFile() (string, error) {
 // Debug prints all configuration registries for debugging
 // purposes.
 func Debug() { v.Debug() }
+
 func (v *Viper) Debug() {
 	fmt.Printf("Aliases:\n%#v\n", v.aliases)
 	fmt.Printf("Override:\n%#v\n", v.override)