random_weighted_test.go

package weighted_test

import (
	"testing"
	"github.com/smallnest/weighted"
)

func TestRandW_Next(t *testing.T) {
	w := weighted.NewRandW()
	w.Add("server1", 4)
	w.Add("server2", 2)
	w.Add("server3", 3)
	w.Add("server4", 1)

	results := make(map[string]int)

	for i := 0; i < 100; i++ {
		s := w.Next().(string)
		results[s]++
	}

	if !checkResults(results["server1"], 20, 70) || !checkResults(results["server2"], 1, 40) || !checkResults(results["server3"], 10, 50) || !checkResults(results["server4"], 1, 30) {
		t.Error("the algorithm is wrong", results)
	}

	w.Reset()
	results = make(map[string]int)

	for i := 0; i < 100; i++ {
		s := w.Next().(string)
		results[s]++
	}

	if !checkResults(results["server1"], 20, 70) || !checkResults(results["server2"], 1, 40) || !checkResults(results["server3"], 10, 50) || !checkResults(results["server4"], 1, 30) {
		t.Error("the algorithm is wrong", results)
	}

	w.RemoveAll()
	w.Add("server1", 7)
	w.Add("server2", 9)
	w.Add("server3", 13)

	results = make(map[string]int)

	for i := 0; i < 29000; i++ {
		s := w.Next().(string)
		results[s]++
	}

	if !checkResults(results["server1"], 6000, 8000) || !checkResults(results["server2"], 8000, 10000) || !checkResults(results["server3"], 12000, 14000) {
		t.Error("the algorithm is wrong", results)
	}

	t.Log("the results: ", results)
}

func checkResults(v, min, max int) bool {
	return v >= min && v <= max
}

func TestRandWZero(t *testing.T)  {
	w := weighted.NewRandW()
	w.Add("a", 0)
	// test panic or not
	_ = w.Next()
}