client: remove unused nsd check allocation result diff func (#17695)

client/serviceregistration/checks/result.go

@@ -88,17 +88,6 @@ func Stub(
 // checks in an allocation.
 type AllocationResults map[structs.CheckID]*structs.CheckQueryResult
 
-// diff returns the set of IDs in ids that are not in m.
-func (m AllocationResults) diff(ids []structs.CheckID) []structs.CheckID {
-	var missing []structs.CheckID
-	for _, id := range ids {
-		if _, exists := m[id]; !exists {
-			missing = append(missing, id)
-		}
-	}
-	return missing
-}
-
 // ClientResults is a holistic view of alloc_id -> check_id -> latest result
 // group and task checks across all allocations on a client.
 type ClientResults map[string]AllocationResults

client/serviceregistration/checks/result_test.go

@@ -111,46 +111,6 @@ func TestChecks_Stub(t *testing.T) {
 	}, result)
 }
 
-func TestChecks_AllocationResults_diff(t *testing.T) {
-	cases := []struct {
-		name    string
-		results []structs.CheckID
-		ids     []structs.CheckID
-		exp     []structs.CheckID
-	}{{
-		name:    "empty results and empty ids",
-		results: nil,
-		ids:     nil,
-		exp:     nil,
-	}, {
-		name:    "empty results and nonempty ids",
-		results: nil,
-		ids:     []structs.CheckID{"aaa", "bbb"},
-		exp:     []structs.CheckID{"aaa", "bbb"},
-	}, {
-		name:    "nonempty results and empty ids",
-		results: []structs.CheckID{"aaa", "bbb"},
-		ids:     nil,
-		exp:     nil,
-	}, {
-		name:    "mix",
-		results: []structs.CheckID{"aaa", "ccc", "ddd", "fff"},
-		ids:     []structs.CheckID{"bbb", "ccc", "fff", "eee"},
-		exp:     []structs.CheckID{"bbb", "eee"},
-	}}
-
-	for _, tc := range cases {
-		t.Run(tc.name, func(t *testing.T) {
-			ar := make(AllocationResults)
-			for _, id := range tc.results {
-				ar[id] = nil
-			}
-			result := ar.diff(tc.ids)
-			must.Eq(t, tc.exp, result)
-		})
-	}
-}
-
 func TestChecks_ClientResults_Insert(t *testing.T) {
 	cr := make(ClientResults)
 	cr.Insert("alloc1", &structs.CheckQueryResult{ID: "qr1", Check: "c1"})