Function TestRangeAssignGroupsUnbalanced

groupbalancer_test.go:198–224

For 66 members, 213 partitions, each member should get 213/66 = 3.22 partitions. This means that in practice, each member should get either 3 or 4 partitions assigned to it. Any other number is a failure.

(t *testing.T)

// This means that in practice, each member should get either 3 or 4 partitions
// assigned to it. Any other number is a failure.
func TestRangeAssignGroupsUnbalanced(t *testing.T) {
	members := []GroupMember{}
	for i := 0; i < 66; i++ {
		members = append(members, GroupMember{
			ID:     strconv.Itoa(i),
			Topics: []string{"topic-1"},
		})
	}
	partitions := []Partition{}
	for i := 0; i < 213; i++ {
		partitions = append(partitions, Partition{
			ID:    i,
			Topic: "topic-1",
		})
	}

	assignments := RangeGroupBalancer{}.AssignGroups(members, partitions)
	if len(assignments) != len(members) {
		t.Fatalf("Assignment count mismatch: %d != %d", len(assignments), len(members))
	}

	for _, m := range assignments {
		if len(m["topic-1"]) < 3 || len(m["topic-1"]) > 4 {
			t.Fatalf("Expected assignment of 3 or 4 partitions, got %d", len(m["topic-1"]))
		}
	}
}

func TestRoundRobinAssignGroups(t *testing.T) {
	newPartitions := func(partitionCount int, topics ...string) []Partition {