implement fakelag (#189)

irc/fakelag_test.go

@@ -0,0 +1,114 @@
+// Copyright (c) 2018 Shivaram Lingamneni <slingamn@cs.stanford.edu>
+// released under the MIT license
+
+package irc
+
+import (
+	"testing"
+	"time"
+)
+
+type mockTime struct {
+	now              time.Time
+	sleepList        []time.Duration
+	lastCheckedSleep int
+}
+
+func (mt *mockTime) Now() (now time.Time) {
+	return mt.now
+}
+
+func (mt *mockTime) Sleep(dur time.Duration) {
+	mt.sleepList = append(mt.sleepList, dur)
+	mt.pause(dur)
+}
+
+func (mt *mockTime) pause(dur time.Duration) {
+	mt.now = mt.now.Add(dur)
+}
+
+func (mt *mockTime) lastSleep() (slept bool, duration time.Duration) {
+	if mt.lastCheckedSleep == len(mt.sleepList)-1 {
+		slept = false
+		return
+	}
+
+	slept = true
+	mt.lastCheckedSleep += 1
+	duration = mt.sleepList[mt.lastCheckedSleep]
+	return
+}
+
+func newFakelagForTesting(window time.Duration, burstLimit uint, throttleMessagesPerWindow uint) (*Fakelag, *mockTime) {
+	fl := NewFakelag(window, burstLimit, throttleMessagesPerWindow)
+	mt := new(mockTime)
+	mt.now, _ = time.Parse("Mon Jan 2 15:04:05 -0700 MST 2006", "Mon Jan 2 15:04:05 -0700 MST 2006")
+	mt.lastCheckedSleep = -1
+	fl.nowFunc = mt.Now
+	fl.sleepFunc = mt.Sleep
+	return fl, mt
+}
+
+func TestFakelag(t *testing.T) {
+	window, _ := time.ParseDuration("1s")
+	fl, mt := newFakelagForTesting(window, 3, 2)
+
+	fl.Touch()
+	slept, _ := mt.lastSleep()
+	if slept {
+		t.Fatalf("should not have slept")
+	}
+
+	interval, _ := time.ParseDuration("100ms")
+	for i := 0; i < 2; i++ {
+		mt.pause(interval)
+		fl.Touch()
+		slept, _ := mt.lastSleep()
+		if slept {
+			t.Fatalf("should not have slept")
+		}
+	}
+
+	mt.pause(interval)
+	fl.Touch()
+	if fl.state != FakelagThrottled {
+		t.Fatalf("should be throttled")
+	}
+	slept, duration := mt.lastSleep()
+	if !slept {
+		t.Fatalf("should have slept due to fakelag")
+	}
+	expected, _ := time.ParseDuration("400ms")
+	if duration != expected {
+		t.Fatalf("incorrect sleep time: %v != %v", expected, duration)
+	}
+
+	fl.Touch()
+	if fl.state != FakelagThrottled {
+		t.Fatalf("should be throttled")
+	}
+	slept, duration = mt.lastSleep()
+	if duration != interval {
+		t.Fatalf("incorrect sleep time: %v != %v", interval, duration)
+	}
+
+	mt.pause(interval * 6)
+	fl.Touch()
+	if fl.state != FakelagThrottled {
+		t.Fatalf("should still be throttled")
+	}
+	slept, duration = mt.lastSleep()
+	if duration != 0 {
+		t.Fatalf("we paused for long enough that we shouldn't sleep here")
+	}
+
+	mt.pause(window * 2)
+	fl.Touch()
+	if fl.state != FakelagBursting {
+		t.Fatalf("should be bursting again")
+	}
+	slept, _ = mt.lastSleep()
+	if slept {
+		t.Fatalf("should not have slept")
+	}
+}