From cb65b4d28d8ff2a4476b3def0f3186898d44dafa Mon Sep 17 00:00:00 2001
From: Luca Bigliardi <shammash@google.com>
Date: Thu, 25 Mar 2021 23:58:27 +0100
Subject: [PATCH] Add factory-like interface to generate Delayers

Will be used to inject fake delayers in objects created during tests

Signed-off-by: Luca Bigliardi <shammash@google.com>
---
 backoff.go      |  9 +++++++--
 fake_delayer.go | 10 ++++++++++
 irc.go          |  7 ++++---
 irc_test.go     |  7 ++-----
 main.go         |  2 +-
 5 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/backoff.go b/backoff.go
index 90492d2..2d16ffe 100644
--- a/backoff.go
+++ b/backoff.go
@@ -24,6 +24,10 @@ import (
 
 type JitterFunc func(int) int
 
+type DelayerMaker interface {
+	NewDelayer(float64, float64, time.Duration) Delayer
+}
+
 type Delayer interface {
 	Delay()
 	DelayContext(context.Context) bool
@@ -62,8 +66,9 @@ func (r *RealTime) After(d time.Duration) <-chan time.Time {
 	return time.After(d)
 }
 
-func NewBackoff(maxBackoff float64, resetDelta float64,
-	durationUnit time.Duration) *Backoff {
+type BackoffMaker struct{}
+
+func (bm *BackoffMaker) NewDelayer(maxBackoff float64, resetDelta float64, durationUnit time.Duration) Delayer {
 	timeTeller := &RealTime{}
 	return NewBackoffForTesting(
 		maxBackoff, resetDelta, durationUnit, jitterFunc, timeTeller)
diff --git a/fake_delayer.go b/fake_delayer.go
index 1b181fb..19b200a 100644
--- a/fake_delayer.go
+++ b/fake_delayer.go
@@ -17,8 +17,18 @@ package main
 import (
 	"context"
 	"log"
+	"time"
 )
 
+type FakeDelayerMaker struct{}
+
+func (fdm *FakeDelayerMaker) NewDelayer(_ float64, _ float64, _ time.Duration) Delayer {
+	return &FakeDelayer{
+		DelayOnChan: false,
+		StopDelay:   make(chan bool),
+	}
+}
+
 type FakeDelayer struct {
 	DelayOnChan bool
 	StopDelay   chan bool
diff --git a/irc.go b/irc.go
index bdd3eb5..f4b5ff0 100644
--- a/irc.go
+++ b/irc.go
@@ -91,7 +91,7 @@ type IRCNotifier struct {
 	BackoffCounter    Delayer
 }
 
-func NewIRCNotifier(stopCtx context.Context, stopWg *sync.WaitGroup, config *Config, alertMsgs chan AlertMsg) (*IRCNotifier, error) {
+func NewIRCNotifier(stopCtx context.Context, stopWg *sync.WaitGroup, config *Config, alertMsgs chan AlertMsg, delayerMaker DelayerMaker) (*IRCNotifier, error) {
 
 	ircConfig := irc.NewConfig(config.IRCNick)
 	ircConfig.Me.Ident = config.IRCNick
@@ -108,7 +108,7 @@ func NewIRCNotifier(stopCtx context.Context, stopWg *sync.WaitGroup, config *Con
 	ircConfig.Timeout = connectionTimeoutSecs * time.Second
 	ircConfig.NewNick = func(n string) string { return n + "^" }
 
-	backoffCounter := NewBackoff(
+	backoffCounter := delayerMaker.NewDelayer(
 		ircConnectMaxBackoffSecs, ircConnectBackoffResetSecs,
 		time.Second)
 
@@ -183,9 +183,10 @@ func (n *IRCNotifier) JoinChannel(channel *IRCChannel) {
 	}
 	log.Printf("Joining %s", channel.Name)
 	n.Client.Join(channel.Name, channel.Password)
+	bm := BackoffMaker{}
 	state := ChannelState{
 		Channel: *channel,
-		BackoffCounter: NewBackoff(
+		BackoffCounter: bm.NewDelayer(
 			ircConnectMaxBackoffSecs, ircConnectBackoffResetSecs,
 			time.Second),
 	}
diff --git a/irc_test.go b/irc_test.go
index bba4cd8..45cd4cf 100644
--- a/irc_test.go
+++ b/irc_test.go
@@ -212,19 +212,16 @@ func makeTestIRCConfig(IRCPort int) *Config {
 }
 
 func makeTestNotifier(t *testing.T, config *Config) (*IRCNotifier, chan AlertMsg, context.CancelFunc, *sync.WaitGroup) {
+	fakeDelayerMaker := &FakeDelayerMaker{}
 	alertMsgs := make(chan AlertMsg)
 	ctx, cancel := context.WithCancel(context.Background())
 	stopWg := sync.WaitGroup{}
 	stopWg.Add(1)
-	notifier, err := NewIRCNotifier(ctx, &stopWg, config, alertMsgs)
+	notifier, err := NewIRCNotifier(ctx, &stopWg, config, alertMsgs, fakeDelayerMaker)
 	if err != nil {
 		t.Fatal(fmt.Sprintf("Could not create IRC notifier: %s", err))
 	}
 	notifier.Client.Config().Flood = true
-	notifier.BackoffCounter = &FakeDelayer{
-		DelayOnChan: false,
-		StopDelay:   make(chan bool),
-	}
 
 	return notifier, alertMsgs, cancel, &stopWg
 }
diff --git a/main.go b/main.go
index 97a4ea2..8a318dc 100644
--- a/main.go
+++ b/main.go
@@ -59,7 +59,7 @@ func main() {
 	alertMsgs := make(chan AlertMsg, config.AlertBufferSize)
 
 	stopWg.Add(1)
-	ircNotifier, err := NewIRCNotifier(ctx, &stopWg, config, alertMsgs)
+	ircNotifier, err := NewIRCNotifier(ctx, &stopWg, config, alertMsgs, &BackoffMaker{})
 	if err != nil {
 		log.Printf("Could not create IRC notifier: %s", err)
 		return