fix: fix default next class ids of x/collection (#960)

* Fix default next class ids

* Update CHANGELOG.md

* Update CHANGELOG.md

* Add unit test

Author: 0Tech

CHANGELOG.md

@@ -55,6 +55,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/collection) [\#954](https://github.com/line/lbm-sdk/pull/954) Remove duplicated events in x/collection Msg/Modify
 * (x/collection) [\#955](https://github.com/line/lbm-sdk/pull/955) Return nil where the parent not exists in x/collection Query/Parent
 * (x/collection) [\#959](https://github.com/line/lbm-sdk/pull/959) Revert #955 and add Query/HasParent into x/collection
+* (x/collection) [\#960](https://github.com/line/lbm-sdk/pull/960) Fix default next class ids of x/collection
 
 ### Removed
 

x/collection/collection.go

@@ -28,8 +28,8 @@ func (x LegacyPermission) String() string {
 func DefaultNextClassIDs(contractID string) NextClassIDs {
 	return NextClassIDs{
 		ContractId:  contractID,
-		Fungible:    sdk.NewUint(0),
-		NonFungible: sdk.NewUint(1 << 28), // "10000000"
+		Fungible:    sdk.NewUint(1),
+		NonFungible: sdk.NewUint(1 << 28).Incr(), // "10000000 + 1"
 	}
 }
 

x/collection/collection_test.go

@@ -171,3 +171,14 @@ func TestParseCoins(t *testing.T) {
 		})
 	}
 }
+
+func TestDefaultNextClassIDs(t *testing.T) {
+	contractID := "deadbeef"
+	require.Equal(t, collection.NextClassIDs{
+		ContractId:  contractID,
+		Fungible:    sdk.NewUint(1),
+		NonFungible: sdk.NewUint(1 << 28).Incr(), // "10000000 + 1"
+	},
+		collection.DefaultNextClassIDs(contractID),
+	)
+}