plugins/ism: add omitempty to Conditions fiels in Trasistion struct

Signed-off-by: Jakob Hahn <jakob.hahn@hetzner.com>

CHANGELOG.md

@@ -7,6 +7,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 ### Added
 
 ### Changed
+- Adjust ISM Transition to omitempty Conditions field ([#609](https://github.com/opensearch-project/opensearch-go/pull/609))
 
 ### Deprecated
 

plugins/ism/api_policies.go

@@ -264,5 +264,5 @@ type PolicyStateTransitionConditionCron struct {
 // PolicyStateTransition is a sub type of PolicyState containing information about transition to other states
 type PolicyStateTransition struct {
 	StateName  string                          `json:"state_name"`
-	Conditions *PolicyStateTransitionCondition `json:"conditions"`
+	Conditions *PolicyStateTransitionCondition `json:"conditions,omitempty"`
 }

plugins/ism/api_policies_test.go

@@ -69,16 +69,29 @@ func TestPoliciesClient(t *testing.T) {
 												Source: "The index {{ctx.index}} failed during policy execution.",
 											},
 										},
-										DefaultState: "test",
+										DefaultState: "transition",
 										States: []ism.PolicyState{
 											ism.PolicyState{
-												Name: "test",
+												Name: "delete",
 												Actions: []ism.PolicyStateAction{
 													ism.PolicyStateAction{
 														Delete: &ism.PolicyStateDelete{},
 													},
 												},
 											},
+											ism.PolicyState{
+												Name: "transition",
+												Actions: []ism.PolicyStateAction{
+													ism.PolicyStateAction{
+														Close: &ism.PolicyStateClose{},
+													},
+													Transitions: &[]ism.PolicyStateTransition{
+														ism.PolicyStateTransition{
+															StateName: "delete",
+														},
+													},
+												},
+											},
 										},
 										Template: []ism.Template{
 											ism.Template{