Adding IsConfigured method to Viper

viper.go

@@ -1205,6 +1205,15 @@ func (v *Viper) IsSet(key string) bool {
 	return val != nil
 }
 
+// IsConfigured checks to see if the key has been set in any of the data locations but defaults.
+// IsConfigured is case-insensitive for a key.
+func IsConfigured(key string) bool { return v.IsConfigured(key) }
+func (v *Viper) IsConfigured(key string) bool {
+	lcaseKey := strings.ToLower(key)
+	val := v.find(lcaseKey, true)
+	return val != nil
+}
+
 // AutomaticEnv has Viper check ENV variables for all.
 // keys set in config, default & flags
 func AutomaticEnv() { v.AutomaticEnv() }

viper_test.go

@@ -999,6 +999,18 @@ func TestIsSet(t *testing.T) {
 	assert.True(t, v.IsSet("helloworld"))
 }
 
+func TestIsConfigured(t *testing.T) {
+	v := New()
+	v.SetDefault("clothing.shoes", true)
+	v.SetConfigType("yaml")
+	v.ReadConfig(bytes.NewBuffer(yamlExample))
+	assert.True(t, v.IsConfigured("clothing.jacket"))
+	assert.False(t, v.IsConfigured("clothing.jackets"))
+	assert.False(t, v.IsConfigured("clothing.shoes"))
+	v.Set("clothing.shoes", false)
+	assert.True(t, v.IsConfigured("clothing.shoes"))
+}
+
 func TestDirsSearch(t *testing.T) {
 
 	root, config, cleanup := initDirs(t)