Fix nil pointer on watch function

This reverts commit 841bd4ebcd.

.travis.yml

@@ -2,9 +2,8 @@ go_import_path: github.com/spf13/viper
 
 language: go
 go:
-  - 1.7.x
+  - 1.10.x
-  - 1.8.x
+  - 1.11.x
-  - 1.9.x
   - tip
 
 os:

README.md

@@ -191,7 +191,7 @@ _When working with ENV variables, it’s important to recognize that Viper
 treats ENV variables as case sensitive._
 
 Viper provides a mechanism to try to ensure that ENV variables are unique. By
-using `SetEnvPrefix`, you can tell Viper to use add a prefix while reading from
+using `SetEnvPrefix`, you can tell Viper to use a prefix while reading from
 the environment variables. Both `BindEnv` and `AutomaticEnv` will use this
 prefix.
 
@@ -373,12 +373,33 @@ how to use Consul.
 
 ### Remote Key/Value Store Example - Unencrypted
 
+#### etcd
 ```go
 viper.AddRemoteProvider("etcd", "http://127.0.0.1:4001","/config/hugo.json")
 viper.SetConfigType("json") // because there is no file extension in a stream of bytes, supported extensions are "json", "toml", "yaml", "yml", "properties", "props", "prop"
 err := viper.ReadRemoteConfig()
 ```
 
+#### Consul
+You need to set a key to Consul key/value storage with JSON value containing your desired config.  
+For example, create a Consul key/value store key `MY_CONSUL_KEY` with value:
+
+```json
+{
+    "port": 8080,
+    "hostname": "myhostname.com"
+}
+```
+
+```go
+viper.AddRemoteProvider("consul", "localhost:8500", "MY_CONSUL_KEY")
+viper.SetConfigType("json") // Need to explicitly set this to json
+err := viper.ReadRemoteConfig()
+
+fmt.Println(viper.Get("port")) // 8080
+fmt.Println(viper.Get("hostname")) // myhostname.com
+```
+
 ### Remote Key/Value Store Example - Encrypted
 
 ```go
@@ -437,6 +458,7 @@ The following functions and methods exist:
  * `GetTime(key string) : time.Time`
  * `GetDuration(key string) : time.Duration`
  * `IsSet(key string) : bool`
+ * `AllSettings() : map[string]interface{}`
 
 One important thing to recognize is that each Get function will return a zero
 value if it’s not found. To check if a given key exists, the `IsSet()` method
@@ -590,6 +612,27 @@ if err != nil {
 }
 ```
 
+### Marshalling to string
+
+You may need to marhsal all the settings held in viper into a string rather than write them to a file. 
+You can use your favorite format's marshaller with the config returned by `AllSettings()`.
+
+```go
+import (
+    yaml "gopkg.in/yaml.v2"
+    // ...
+) 
+
+func yamlStringSettings() string {
+    c := viper.AllSettings()
+	bs, err := yaml.Marshal(c)
+	if err != nil {
+        t.Fatalf("unable to marshal config to YAML: %v", err)
+    }
+	return string(bs)
+}
+```
+
 ## Viper or Vipers?
 
 Viper comes ready to use out of the box. There is no configuration or

go.mod

@@ -0,0 +1,16 @@
+module github.com/spf13/viper
+
+require (
+	github.com/fsnotify/fsnotify v1.4.7
+	github.com/hashicorp/hcl v1.0.0
+	github.com/magiconair/properties v1.8.0
+	github.com/mitchellh/mapstructure v1.0.0
+	github.com/pelletier/go-toml v1.2.0
+	github.com/spf13/afero v1.1.2
+	github.com/spf13/cast v1.2.0
+	github.com/spf13/jwalterweatherman v1.0.0
+	github.com/spf13/pflag v1.0.2
+	golang.org/x/sys v0.0.0-20180906133057-8cf3aee42992 // indirect
+	golang.org/x/text v0.3.0 // indirect
+	gopkg.in/yaml.v2 v2.2.1
+)

go.sum

@@ -0,0 +1,26 @@
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
+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/magiconair/properties v1.8.0 h1:LLgXmsheXeRoUOBOjtwPQCWIYqM/LU1ayDtDePerRcY=
+github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
+github.com/mitchellh/mapstructure v1.0.0 h1:vVpGvMXJPqSDh2VYHF7gsfQj8Ncx+Xw5Y1KHeTRY+7I=
+github.com/mitchellh/mapstructure v1.0.0/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/pelletier/go-toml v1.2.0 h1:T5zMGML61Wp+FlcbWjRDT7yAxhJNAiPPLOFECq181zc=
+github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/spf13/afero v1.1.2 h1:m8/z1t7/fwjysjQRYbP0RD+bUIF/8tJwPdEZsI83ACI=
+github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
+github.com/spf13/cast v1.2.0 h1:HHl1DSRbEQN2i8tJmtS6ViPyHx35+p51amrdsiTCrkg=
+github.com/spf13/cast v1.2.0/go.mod h1:r2rcYCSwa1IExKTDiTfzaxqT2FNHs8hODu4LnUfgKEg=
+github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=
+github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
+github.com/spf13/pflag v1.0.2 h1:Fy0orTDgHdbnzHcsOgfCN4LtHf0ec3wwtiwJqwvf3Gc=
+github.com/spf13/pflag v1.0.2/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+golang.org/x/sys v0.0.0-20180906133057-8cf3aee42992 h1:BH3eQWeGbwRU2+wxxuuPOdFBmaiBH81O8BugSjHeTFg=
+golang.org/x/sys v0.0.0-20180906133057-8cf3aee42992/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
+gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

viper.go

@@ -113,6 +113,23 @@ func (fnfe ConfigFileNotFoundError) Error() string {
 	return fmt.Sprintf("Config File %q Not Found in %q", fnfe.name, fnfe.locations)
 }
 
+// A DecoderConfigOption can be passed to viper.Unmarshal to configure
+// mapstructure.DecoderConfig options
+type DecoderConfigOption func(*mapstructure.DecoderConfig)
+
+// DecodeHook returns a DecoderConfigOption which overrides the default
+// DecoderConfig.DecodeHook value, the default is:
+//
+//  mapstructure.ComposeDecodeHookFunc(
+//		mapstructure.StringToTimeDurationHookFunc(),
+//		mapstructure.StringToSliceHookFunc(","),
+//	)
+func DecodeHook(hook mapstructure.DecodeHookFunc) DecoderConfigOption {
+	return func(c *mapstructure.DecoderConfig) {
+		c.DecodeHook = hook
+	}
+}
+
 // Viper is a prioritized configuration registry. It
 // maintains a set of configuration sources, fetches
 // values to populate those, and provides them according
@@ -633,8 +650,10 @@ func (v *Viper) Get(key string) interface{} {
 			return cast.ToBool(val)
 		case string:
 			return cast.ToString(val)
-		case int64, int32, int16, int8, int:
+		case int32, int16, int8, int:
 			return cast.ToInt(val)
+		case int64:
+			return cast.ToInt64(val)
 		case float64, float32:
 			return cast.ToFloat64(val)
 		case time.Time:
@@ -684,6 +703,12 @@ 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 {
@@ -741,9 +766,11 @@ func (v *Viper) GetSizeInBytes(key string) uint {
 }
 
 // UnmarshalKey takes a single key and unmarshals it into a Struct.
-func UnmarshalKey(key string, rawVal interface{}) error { return v.UnmarshalKey(key, rawVal) }
+func UnmarshalKey(key string, rawVal interface{}, opts ...DecoderConfigOption) error {
-func (v *Viper) UnmarshalKey(key string, rawVal interface{}) error {
+	return v.UnmarshalKey(key, rawVal, opts...)
-	err := decode(v.Get(key), defaultDecoderConfig(rawVal))
+}
+func (v *Viper) UnmarshalKey(key string, rawVal interface{}, opts ...DecoderConfigOption) error {
+	err := decode(v.Get(key), defaultDecoderConfig(rawVal, opts...))
 
 	if err != nil {
 		return err
@@ -756,9 +783,11 @@ func (v *Viper) UnmarshalKey(key string, rawVal interface{}) error {
 
 // Unmarshal unmarshals the config into a Struct. Make sure that the tags
 // on the fields of the structure are properly set.
-func Unmarshal(rawVal interface{}) error { return v.Unmarshal(rawVal) }
+func Unmarshal(rawVal interface{}, opts ...DecoderConfigOption) error {
-func (v *Viper) Unmarshal(rawVal interface{}) error {
+	return v.Unmarshal(rawVal, opts...)
-	err := decode(v.AllSettings(), defaultDecoderConfig(rawVal))
+}
+func (v *Viper) Unmarshal(rawVal interface{}, opts ...DecoderConfigOption) error {
+	err := decode(v.AllSettings(), defaultDecoderConfig(rawVal, opts...))
 
 	if err != nil {
 		return err
@@ -771,8 +800,8 @@ func (v *Viper) Unmarshal(rawVal interface{}) error {
 
 // defaultDecoderConfig returns default mapsstructure.DecoderConfig with suppot
 // of time.Duration values & string slices
-func defaultDecoderConfig(output interface{}) *mapstructure.DecoderConfig {
+func defaultDecoderConfig(output interface{}, opts ...DecoderConfigOption) *mapstructure.DecoderConfig {
-	return &mapstructure.DecoderConfig{
+	c := &mapstructure.DecoderConfig{
 		Metadata:         nil,
 		Result:           output,
 		WeaklyTypedInput: true,
@@ -781,6 +810,10 @@ func defaultDecoderConfig(output interface{}) *mapstructure.DecoderConfig {
 			mapstructure.StringToSliceHookFunc(","),
 		),
 	}
+	for _, opt := range opts {
+		opt(c)
+	}
+	return c
 }
 
 // A wrapper around mapstructure.Decode that mimics the WeakDecode functionality
@@ -1110,7 +1143,7 @@ func (v *Viper) SetDefault(key string, value interface{}) {
 	deepestMap[lastKey] = value
 }
 
-// Set sets the value for the key in the override regiser.
+// Set sets the value for the key in the override register.
 // Set is case-insensitive for a key.
 // Will be used instead of values obtained via
 // flags, config file, ENV, default, or key/value store.

viper_test.go

@@ -7,6 +7,7 @@ package viper
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -18,6 +19,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/mitchellh/mapstructure"
 	"github.com/spf13/afero"
 	"github.com/spf13/cast"
 
@@ -503,6 +505,42 @@ func TestUnmarshal(t *testing.T) {
 	assert.Equal(t, &config{Name: "Steve", Port: 1234, Duration: time.Second + time.Millisecond}, &C)
 }
 
+func TestUnmarshalWithDecoderOptions(t *testing.T) {
+	Set("credentials", "{\"foo\":\"bar\"}")
+
+	opt := DecodeHook(mapstructure.ComposeDecodeHookFunc(
+		mapstructure.StringToTimeDurationHookFunc(),
+		mapstructure.StringToSliceHookFunc(","),
+		// Custom Decode Hook Function
+		func(rf reflect.Kind, rt reflect.Kind, data interface{}) (interface{}, error) {
+			if rf != reflect.String || rt != reflect.Map {
+				return data, nil
+			}
+			m := map[string]string{}
+			raw := data.(string)
+			if raw == "" {
+				return m, nil
+			}
+			return m, json.Unmarshal([]byte(raw), &m)
+		},
+	))
+
+	type config struct {
+		Credentials map[string]string
+	}
+
+	var C config
+
+	err := Unmarshal(&C, opt)
+	if err != nil {
+		t.Fatalf("unable to decode into struct, %v", err)
+	}
+
+	assert.Equal(t, &config{
+		Credentials: map[string]string{"foo": "bar"},
+	}, &C)
+}
+
 func TestBindPFlags(t *testing.T) {
 	v := New() // create independent Viper object
 	flagSet := pflag.NewFlagSet("test", pflag.ContinueOnError)
@@ -1064,8 +1102,8 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("pop != 37890, = %d", pop)
 	}
 
-	if pop := v.GetInt("hello.lagrenum"); pop != 765432101234567 {
+	if pop := v.GetInt32("hello.pop"); pop != int32(37890) {
-		t.Fatalf("lagrenum != 765432101234567, = %d", pop)
+		t.Fatalf("pop != 37890, = %d", pop)
 	}
 
 	if pop := v.GetInt64("hello.lagrenum"); pop != int64(765432101234567) {
@@ -1088,8 +1126,8 @@ func TestMergeConfig(t *testing.T) {
 		t.Fatalf("pop != 45000, = %d", pop)
 	}
 
-	if pop := v.GetInt("hello.lagrenum"); pop != 7654321001234567 {
+	if pop := v.GetInt32("hello.pop"); pop != int32(45000) {
-		t.Fatalf("lagrenum != 7654321001234567, = %d", pop)
+		t.Fatalf("pop != 45000, = %d", pop)
 	}
 
 	if pop := v.GetInt64("hello.lagrenum"); pop != int64(7654321001234567) {