ygot.Diff generating gnmi update TypeVal as bool for leaf type yang.Empty

[soumiksamanta]

ygot v0.8.11

I have this yang defined

module dummy {
    yang-version "1";
    namespace "urn:dummy/dummy";
    prefix "dummy";
    grouping dummy-entry {
        list entries {
            key "name";
            leaf name {
                type string;
            }
            leaf city {
                type string;
            }
            leaf primary {
                type empty;
            }
        }
    }
    uses dummy-entry;
}

I created two Device{} structs with the following jsons

Object1:

{
    "entries":[
      {  
            "name": "samanta",
            "city": "xyz"
      }
    ]
}

Object2:

{
    "entries":[
      {  
            "name": "samanta",
            "city": "xyz"
      },
      {  
            "name": "soumik",
            "city": "abc"
      }
    ]
}

dummy1Data := &dummy.Device{}
dummy.Unmarshal("object1.json", dummy1Data)
dummy2Data := &dummy.Device{}
dummy.Unmarshal("object2.json", dummy2Data)

Now when I try to do a diff of dummy1Data and dummy2Data
diffData, err = ygot.Diff(dummy2Data, dummy1Data)

I get the following gnmi.Notification object

update: <
  path: <
    elem: <
      name: "entries"
      key: <
        key: "name"
        value: "samanta"
      >
    >
    elem: <
      name: "primary"
    >
  >
  val: <
    bool_val: false
  >
>
update: <
  path: <
    elem: <
      name: "entries"
      key: <
        key: "name"
        value: "soumik"
      >
    >
    elem: <
      name: "city"
    >
  >
  val: <
    string_val: "abc"
  >
>
update: <
  path: <
    elem: <
      name: "entries"
      key: <
        key: "name"
        value: "soumik"
      >
    >
    elem: <
      name: "name"
    >
  >
  val: <
    string_val: "soumik"
  >
>
update: <
  path: <
    elem: <
      name: "entries"
      key: <
        key: "name"
        value: "soumik"
      >
    >
    elem: <
      name: "primary"
    >
  >
  val: <
    bool_val: false
  >
>
update: <
  path: <
    elem: <
      name: "entries"
      key: <
        key: "name"
        value: "samanta"
      >
    >
    elem: <
      name: "city"
    >
  >
  val: <
    string_val: "xyz"
  >
>
update: <
  path: <
    elem: <
      name: "entries"
      key: <
        key: "name"
        value: "samanta"
      >
    >
    elem: <
      name: "name"
    >
  >
  val: <
    string_val: "samanta"
  >
>

In the notification object, the yang.Empty path "primary" is set as value "bool". which is not conforming to the yang model. And as per https://tools.ietf.org/html/rfc7951#section-6.9 yang.Empty is actually a slice

[soumiksamanta]

May be similar to #291

[soumiksamanta]

@robshakir Actually I want to get the gnmiNotifications encoded in JSON_IETF, wherein a YangEmpty leaf if not present should not create an update with bool(false).

[wenovus]

Reproduced, taking a look.

[soumiksamanta]

diff --git a/ygot/render_test.go b/ygot/render_test.go
index 3e06ad7..52f0a18 100644
--- a/ygot/render_test.go
+++ b/ygot/render_test.go
@@ -918,8 +918,9 @@ func (*pathElemExample) IsYANGGoStruct() {}
 
 // pathElemExampleChild is an example struct that is used as a list child struct.
 type pathElemExampleChild struct {
-       Val        *string `path:"val|config/val"`
-       OtherField *uint8  `path:"other-field"`
+       Val        *string   `path:"val|config/val"`
+       OtherField *uint8    `path:"other-field"`
+       Empty      YANGEmpty `path:"empty-field"`
 }

Just added the above empty field to pathElemExampleChild, and the Diff tests failed

1. "add an item to a list"
2. "remove item from list"

[wenovus]

Thanks, added a similar test to the fix.

[wenovus]

in v.0.8.12