Switched viper from 1.10.1 to 1.18.2 and there was a error when running the code.

[alien0119]

When I use Viper 1.10.1 to run the code below, it runs with no error.
However, when I switch Viper to 1.18.2, the following error occurs:

panic: interface conversion: interface {} is map[string]interface {}, not map[interface {}]interface {}

When I change the line modelObj := modelDefObjs[modelIdx].(map[interface{}]interface{}) to modelObj := modelDefObjs[modelIdx].(map[string]interface{}) and use Viper 1.10.1, the following error occurs:

panic: interface conversion: interface {} is map[interface {}]interface {}, not map[string]interface {}

Could anyone tell me why this is happening?

import (
	"bytes"
	"fmt"
	"github.com/spf13/viper"
)

func main() {
	str := "dataSchema:\r\n  formatVersion: 1.0\r\n  dmodelVersion: v0.0.12\r\n  serviceModName: lightdevmgmtservice\r\n  modelDef:\r\n    - CommonDevInfo:\r\n        desc: common device interface info\r\n        ifType: API(R)\r\n        fields:\r\n          - tenantId: String(64)! @default(\"default-organization-id\") @index(commondev_info_key) @unique @pub\r\n          - neResId: String(36)! @primaryKey @pub\r\n          - neId: Int! @index @pub\r\n          - name: String(300)! @pub @index\r\n          - typeName: String(64) @pub @index\r\n          - typeId: String(64) @pub\r\n          - uniqueAddress: String(255)! @index(commondev_info_key) @unique @pub\r\n          - remark: String(255) @pub\r\n          - alias: String(255) @pub\r\n          - extendInfo: String(6000) @pub\r\n          - macAddress: String(255) @pub\r\n    \r\n    - CommonDevPortInfo:\r\n        desc: common device interface info\r\n        ifType: API(R)\r\n        fields:\r\n          - tenantId: String(64)! @default(\"default-organization-id\") @pub\r\n          - neResId: String(36)! @index(key_common_dev_port) @unique @pub\r\n          - neId: Int! @index(key_common_dev_port) @unique @pub\r\n          - ifType: Int! @pub\r\n          - ifIndex: Int! @index(key_common_dev_port) @unique @pub\r\n          - ifPortDesc: String(255)! @index(key_common_dev_port) @unique @pub\r\n          - ifAdminStatus: ifStatusKind! @pub\r\n          - ifOperStatus: ifStatusKind! @pub\r\n          - ifIPAddr: String(255)! @index(key_common_dev_port) @unique @pub\r\n          - ifIPMask: String(255) @pub\r\n          - ifNetAddr: String(255) @pub\r\n          - ifPhyAddr: String(255) @pub\r\n          \r\n    - CommonDevPolling:\r\n        desc: common device polling regist info\r\n        fields:\r\n          - tenantId: String(64)! @default(\"default-organization-id\") @pub\r\n          - neResId: String(36)! @primaryKey @pub\r\n          - longPollingTime: Int! @pub\r\n          - longPollingInterval: Int! @pub \r\n          - shortPollingTime: Int! @pub\r\n          - pollingStatus: pollingStatusKind! @pub\r\n          - connectStatus: connectStatusKind! @pub\r\n\r\n    - LocalNM:\r\n        desc: local NM info\r\n        ifType: UI(U)|API(R)\r\n        fields:\r\n          - tenantId: String(64)! @default(\"default-organization-id\") @pub\r\n          - resId: String(36)! @primaryKey @pub\r\n          - neId: Int! @index @unique @pub\r\n          - name: String(255)! @pub @index\r\n          - ipAddr: String(128) @pub @index\r\n          - isLocalNM: Bool @pub\r\n          - typeName: String(64) @pub\r\n          - typeId: String(64) @pub          \r\n          - remark: String(255) @pub\r\n          - owner: String(64) @pub          \r\n          - userLabel: String(255) @pub\r\n          - userName: String(255) @pub             \r\n\r\n    - NeTypeInfo:\r\n        desc: ne type register info\r\n        fields:\r\n          - typeId: String(64)! @primaryKey @pub\r\n          - typeName: String(64) @pub\r\n          - protocolType: Int! @pub\r\n          - oid: String(128) @pub\r\n          - serialName: String(128) @pub\r\n\r\n  enumDef:\r\n    - ifStatusKind:\r\n        type: Int\r\n        elems:\r\n            - up: 1\r\n            - down: 2\r\n            - testing: 3\r\n            \r\n    - connectStatusKind:\r\n        type: Int\r\n        elems:\r\n           - online: 1\r\n           - unknown: 2\r\n           - offline: 3\r\n           \r\n    - pollingStatusKind:\r\n        type: Int\r\n        elems:\r\n           - free: 1\r\n           - polling: 2"
	vip := viper.New()
	vip.SetConfigType("yaml")
	byteRead := bytes.NewReader([]byte(str))
	_ = vip.ReadConfig(byteRead)
	mdData := vip.Get("dataSchema.modelDef")
	modelDefObjs, _ := mdData.([]interface{})
	for modelIdx := range modelDefObjs {
		modelObj := modelDefObjs[modelIdx].(map[interface{}]interface{})
		for modelKey := range modelObj {
			fmt.Println(modelKey)
		}
	}
}

[sagikazarmark]

Chances are it's because the new version of the yaml library uses map[string]interface{} instead of map[interface{}]interface{}. That's the correct internal model for Viper anyway.

[alien0119]

Thank you.
And I also have a question.
When I run the code above with Viper 1.10.1, the output is

CommonDevInfo
CommonDevPortInfo
CommonDevPolling
LocalNM
NeTypeInfo

However, when I run the code with Viper 1.18.2, the output is

commondevinfo
commondevportinfo
commondevpolling
localnm
netypeinfo

All uppercase letters have been changed to lowercase that makes me confused a lot.
Could u tell me how can I get the output in uppercase letters with Viper 1.18.2 when I run the code above?