From 2e49de5fa0710eb0c41ff1265aae93102f71380d Mon Sep 17 00:00:00 2001
From: Saxon <saxon@ausocean.org>
Date: Thu, 14 Mar 2019 08:30:26 +1030
Subject: [PATCH] revid: newMultiSender panics if active function is not
 provided

---
 revid/revid.go        |  4 ++--
 revid/senders.go      |  6 +++---
 revid/senders_test.go | 41 +++++------------------------------------
 3 files changed, 10 insertions(+), 41 deletions(-)

diff --git a/revid/revid.go b/revid/revid.go
index 00679285..3a3e28f7 100644
--- a/revid/revid.go
+++ b/revid/revid.go
@@ -216,7 +216,7 @@ func (r *Revid) reset(config Config) error {
 	// encoder to revid's encoder slice, and give this encoder the mtsSenders
 	// as a destination.
 	if len(mtsSenders) != 0 {
-		ms, _ := newMultiSender(mtsSenders, r.IsRunning)
+		ms := newMultiSender(mtsSenders, r.IsRunning)
 		if err != nil {
 			return err
 		}
@@ -228,7 +228,7 @@ func (r *Revid) reset(config Config) error {
 	// encoder to revid's encoder slice, and give this encoder the flvSenders
 	// as a destination.
 	if len(flvSenders) != 0 {
-		ms, _ := newMultiSender(flvSenders, r.IsRunning)
+		ms := newMultiSender(flvSenders, r.IsRunning)
 		e, err := flv.NewEncoder(ms, true, true, int(r.config.FrameRate))
 		if err != nil {
 			return err
diff --git a/revid/senders.go b/revid/senders.go
index d5071a9f..bba427da 100644
--- a/revid/senders.go
+++ b/revid/senders.go
@@ -63,15 +63,15 @@ type multiSender struct {
 // newMultiSender returns a pointer to a new multiSender. active is a function
 // to indicate the state of the multiSenders owner i.e. whether it is running
 // or not.
-func newMultiSender(senders []loadSender, active func() bool) (*multiSender, error) {
+func newMultiSender(senders []loadSender, active func() bool) *multiSender {
 	if active == nil {
-		return nil, errors.New("multi sender requires that active func is provided")
+		panic("multi sender requires that active func is provided")
 	}
 	s := &multiSender{
 		senders: senders,
 		active:  active,
 	}
-	return s, nil
+	return s
 }
 
 // Write implements io.Writer. The written slice will be sent to each loadSender
diff --git a/revid/senders_test.go b/revid/senders_test.go
index 392dc8ed..82991a3f 100644
--- a/revid/senders_test.go
+++ b/revid/senders_test.go
@@ -256,22 +256,6 @@ func TestMtsSenderDiscontinuity(t *testing.T) {
 	}
 }
 
-// TestNewMultiSender checks that newMultiSender performs as expected when an
-// active function is not provided, and when an active function is provided.
-func TestNewMultiSender(t *testing.T) {
-	// First test without giving an 'active' function.
-	_, err := newMultiSender(nil, nil)
-	if err == nil {
-		t.Fatal("did not get expected error")
-	}
-
-	// Now test with providing an active function.
-	_, err = newMultiSender(nil, func() bool { return true })
-	if err != nil {
-		t.Fatalf("unespected error: %v", err)
-	}
-}
-
 // dummyLoadSender is a loadSender implementation that allows us to simulate
 // the behaviour of a loadSender and check that it performas as expected.
 type dummyLoadSender struct {
@@ -337,10 +321,7 @@ func TestMultiSenderWrite(t *testing.T) {
 		newDummyLoadSender(false, false),
 		newDummyLoadSender(false, false),
 	}
-	ms, err := newMultiSender(senders, func() bool { return true })
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
+	ms := newMultiSender(senders, func() bool { return true })
 
 	// Perform some multiSender writes.
 	const noOfWrites = 5
@@ -376,10 +357,7 @@ func TestMultiSenderNotActiveNoRetry(t *testing.T) {
 		return active
 	}
 
-	ms, err := newMultiSender(senders, activeFunc)
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
+	ms := newMultiSender(senders, activeFunc)
 
 	// We will perform two writes. We expect the second write not to be complete,
 	// i.e. the senders should not send anything on this write.
@@ -418,10 +396,7 @@ func TestMultiSenderNotActiveRetry(t *testing.T) {
 		return active
 	}
 
-	ms, err := newMultiSender(senders, activeFunc)
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
+	ms := newMultiSender(senders, activeFunc)
 
 	// We run this in background so that we can change running state during the
 	// the write. We then expect done to be true after some period of time.
@@ -453,10 +428,7 @@ func TestMultiSenderFailNoRetry(t *testing.T) {
 		newDummyLoadSender(false, false),
 	}
 
-	ms, err := newMultiSender(senders, func() bool { return true })
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
+	ms := newMultiSender(senders, func() bool { return true })
 
 	// We will perform two writes. We expect the second write not to be complete,
 	// i.e. the senders should not send anything on this write.
@@ -507,10 +479,7 @@ func TestMultiSenderFailNoRetry(t *testing.T) {
 func TestMultiSenderFailRetry(t *testing.T) {
 	// NB: This is only being tested with one sender - this is AusOcean's use case.
 	senders := []loadSender{newDummyLoadSender(false, true)}
-	ms, err := newMultiSender(senders, func() bool { return true })
-	if err != nil {
-		t.Fatalf("Unexpected error: %v", err)
-	}
+	ms := newMultiSender(senders, func() bool { return true })
 
 	// Perform one write with successful send.
 	ms.Write([]byte{0x00})