From 2456f45836b0054e756d44451f7644879ecfef76 Mon Sep 17 00:00:00 2001
From: Nicholas Thompson <git@hoekwil.com>
Date: Thu, 7 Mar 2019 19:04:15 +0200
Subject: [PATCH] Added golangci linting and improved what was required

---
 .golangci.yml                  |  29 +++++
 Makefile                       |   6 +-
 cmd/guimock/main.go            |   3 +-
 cmd/guimock/mock.go            |  90 --------------
 cmd/invertercli/invertercli.go |   8 +-
 cmd/invertergui/main.go        |   2 +-
 frontend/binary.go             |  12 +-
 mk2if/mk2.go                   | 211 +++++++++++++++------------------
 mk2if/mk2interface.go          |   1 -
 mk2if/mockmk2.go               |  71 +++++++++++
 webgui/munin.go                |   9 +-
 webgui/webgui.go               |  10 +-
 webgui/webgui_test.go          |  34 +++---
 websocket/client.go            |  11 +-
 websocket/hub.go               |   2 +-
 15 files changed, 244 insertions(+), 255 deletions(-)
 create mode 100644 .golangci.yml
 delete mode 100644 cmd/guimock/mock.go
 create mode 100644 mk2if/mockmk2.go

diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..aa9991d
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,29 @@
+run:
+  deadline: 10m
+
+linters:
+  enable-all: false
+  enable:
+    # Enabled by default in golangci-lint v1.13.2
+    - deadcode
+    - errcheck
+    - govet
+    - ineffassign
+    - typecheck
+    - varcheck
+    # Disabled by default in golangci-lint v1.13.2
+    - dupl
+    - goconst
+    - gofmt
+    - golint
+    - unconvert
+    # The following result in high memory usage (>1GB)
+    # https://github.com/golangci/golangci-lint/issues/337
+    - staticcheck
+    - structcheck
+    - gosimple
+    - unused
+
+issues:
+  max-per-linter: 0
+  max-same-issues: 0
diff --git a/Makefile b/Makefile
index e9107eb..3827a84 100644
--- a/Makefile
+++ b/Makefile
@@ -29,8 +29,7 @@
 .PHONY: test install gofmt docker statik
 
 build:
-	go build ./cmd/invertergui/
-	go build ./cmd/invertercli/
+	go build ./cmd/...
 
 all: build gofmt test
 
@@ -51,3 +50,6 @@ docker:
 
 statik:
 	statik -p=frontend -src=./frontend/root
+
+lint:
+	golangci-lint run
diff --git a/cmd/guimock/main.go b/cmd/guimock/main.go
index 3441ce8..da02c08 100644
--- a/cmd/guimock/main.go
+++ b/cmd/guimock/main.go
@@ -6,6 +6,7 @@ import (
 	"net/http"
 
 	"github.com/hpdvanwyk/invertergui/frontend"
+	"github.com/hpdvanwyk/invertergui/mk2if"
 	"github.com/hpdvanwyk/invertergui/webgui"
 
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -13,7 +14,7 @@ import (
 
 func main() {
 	addr := flag.String("addr", ":8080", "TCP address to listen on.")
-	mk2 := NewMk2Mock()
+	mk2 := mk2if.NewMk2Mock()
 	gui := webgui.NewWebGui(mk2)
 
 	http.Handle("/", frontend.NewStatic())
diff --git a/cmd/guimock/mock.go b/cmd/guimock/mock.go
deleted file mode 100644
index cdeda43..0000000
--- a/cmd/guimock/mock.go
+++ /dev/null
@@ -1,90 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"time"
-
-	"github.com/hpdvanwyk/invertergui/mk2if"
-)
-
-type mock struct {
-	c chan *mk2if.Mk2Info
-}
-
-func NewMk2Mock() mk2if.Mk2If {
-	tmp := &mock{
-		c: make(chan *mk2if.Mk2Info, 1),
-	}
-	go tmp.genMockValues()
-	return tmp
-}
-
-func genBaseLeds(state mk2if.LEDstate) map[mk2if.Led]mk2if.LEDstate {
-	return map[mk2if.Led]mk2if.LEDstate{
-		mk2if.LedMain:        state,
-		mk2if.LedAbsorption:  state,
-		mk2if.LedBulk:        state,
-		mk2if.LedFloat:       state,
-		mk2if.LedInverter:    state,
-		mk2if.LedOverload:    state,
-		mk2if.LedLowBattery:  state,
-		mk2if.LedTemperature: state,
-	}
-}
-
-func (m *mock) GetMk2Info() *mk2if.Mk2Info {
-	return &mk2if.Mk2Info{
-		OutCurrent:   2.0,
-		InCurrent:    2.3,
-		OutVoltage:   230.0,
-		InVoltage:    230.1,
-		BatVoltage:   25,
-		BatCurrent:   -10,
-		InFrequency:  50,
-		OutFrequency: 50,
-		ChargeState:  1,
-		Errors:       nil,
-		Timestamp:    time.Now(),
-		LEDs:         genBaseLeds(mk2if.LedOff),
-	}
-}
-
-func (m *mock) C() chan *mk2if.Mk2Info {
-	return m.c
-}
-
-func (m *mock) Close() {
-
-}
-
-func (m *mock) genMockValues() {
-	mult := 1.0
-	ledState := mk2if.LedOff
-	for {
-		input := &mk2if.Mk2Info{
-			OutCurrent:   2.0 * mult,
-			InCurrent:    2.3 * mult,
-			OutVoltage:   230.0 * mult,
-			InVoltage:    230.1 * mult,
-			BatVoltage:   25 * mult,
-			BatCurrent:   -10 * mult,
-			InFrequency:  50 * mult,
-			OutFrequency: 50 * mult,
-			ChargeState:  1 * mult,
-			Errors:       nil,
-			Timestamp:    time.Now(),
-			Valid:        true,
-			LEDs:         genBaseLeds(ledState),
-		}
-
-		ledState = (ledState + 1) % 3
-
-		mult = mult - 0.1
-		if mult < 0 {
-			mult = 1.0
-		}
-		fmt.Printf("Sending\n")
-		m.c <- input
-		time.Sleep(1 * time.Second)
-	}
-}
diff --git a/cmd/invertercli/invertercli.go b/cmd/invertercli/invertercli.go
index e1fe897..6cafb6d 100644
--- a/cmd/invertercli/invertercli.go
+++ b/cmd/invertercli/invertercli.go
@@ -3,14 +3,15 @@ package main
 import (
 	"flag"
 	"fmt"
-	"github.com/hpdvanwyk/invertergui/mk2if"
-	"github.com/mikepb/go-serial"
 	"io"
 	"log"
 	"net"
 	"os"
 	"os/signal"
 	"syscall"
+
+	"github.com/hpdvanwyk/invertergui/mk2if"
+	"github.com/mikepb/go-serial"
 )
 
 // Basic CLI to serve as example lib usage
@@ -46,10 +47,11 @@ func main() {
 	}
 	defer p.Close()
 	mk2, err := mk2if.NewMk2Connection(p)
-	defer mk2.Close()
 	if err != nil {
 		panic(err)
 	}
+	defer mk2.Close()
+
 	c := mk2.C()
 	sigterm := make(chan os.Signal, 1)
 	signal.Notify(sigterm, syscall.SIGTERM, os.Interrupt)
diff --git a/cmd/invertergui/main.go b/cmd/invertergui/main.go
index a1a4cb6..0ef9e0e 100644
--- a/cmd/invertergui/main.go
+++ b/cmd/invertergui/main.go
@@ -76,10 +76,10 @@ func main() {
 	}
 	defer p.Close()
 	mk2, err := mk2if.NewMk2Connection(p)
-	defer mk2.Close()
 	if err != nil {
 		panic(err)
 	}
+	defer mk2.Close()
 
 	gui := webgui.NewWebGui(mk2)
 
diff --git a/frontend/binary.go b/frontend/binary.go
index 3935a59..a42ec02 100644
--- a/frontend/binary.go
+++ b/frontend/binary.go
@@ -7,20 +7,10 @@ import (
 	"net/http"
 )
 
-type static struct {
-	http.FileSystem
-}
-
 func NewStatic() http.Handler {
 	statikFs, err := fs.New()
 	if err != nil {
 		log.Fatal(err)
 	}
-	return &static{
-		FileSystem: statikFs,
-	}
-}
-
-func (s *static) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	http.FileServer(s).ServeHTTP(w, r)
+	return http.FileServer(statikFs)
 }
diff --git a/mk2if/mk2.go b/mk2if/mk2.go
index 8fb04a5..f597f90 100644
--- a/mk2if/mk2.go
+++ b/mk2if/mk2.go
@@ -16,70 +16,67 @@ type scaling struct {
 }
 
 type mk2Ser struct {
-	info   *Mk2Info
-	report *Mk2Info
-	p      io.ReadWriter
-	sc     []scaling
-	scN    int
-	run    chan struct{}
-	locked bool
-	sync.RWMutex
-	infochan chan *Mk2Info
-	wg       sync.WaitGroup
+	info       *Mk2Info
+	p          io.ReadWriter
+	scales     []scaling
+	scaleCount int
+	run        chan struct{}
+	frameLock  bool
+	infochan   chan *Mk2Info
+	wg         sync.WaitGroup
 }
 
 func NewMk2Connection(dev io.ReadWriter) (Mk2If, error) {
 	mk2 := &mk2Ser{}
 	mk2.p = dev
 	mk2.info = &Mk2Info{}
-	mk2.report = &Mk2Info{}
-	mk2.scN = 0
-	mk2.locked = false
-	mk2.sc = make([]scaling, 0)
+	mk2.scaleCount = 0
+	mk2.frameLock = false
+	mk2.scales = make([]scaling, 0, 14)
 	mk2.setTarget()
 	mk2.run = make(chan struct{})
 	mk2.infochan = make(chan *Mk2Info)
 	mk2.wg.Add(1)
-	go mk2.frameLock()
+	go mk2.frameLocker()
 	return mk2, nil
 }
 
 // Locks to incoming frame.
-func (mk2 *mk2Ser) frameLock() {
+func (m *mk2Ser) frameLocker() {
 
 	frame := make([]byte, 256)
 	var size byte
 	for {
 		select {
-		case <-mk2.run:
-			mk2.wg.Done()
+		case <-m.run:
+			m.wg.Done()
 			return
 		default:
 		}
-		if mk2.locked {
-			size = mk2.readByte()
-			l, err := io.ReadFull(mk2.p, frame[0:int(size)+1])
+		if m.frameLock {
+			size = m.readByte()
+			l, err := io.ReadFull(m.p, frame[0:int(size)+1])
 			if err != nil {
-				mk2.addError(fmt.Errorf("Read Error: %v", err))
-				mk2.locked = false
+				m.addError(fmt.Errorf("Read Error: %v", err))
+				m.frameLock = false
 			} else if l != int(size)+1 {
-				mk2.addError(errors.New("Read Length Error"))
-				mk2.locked = false
+				m.addError(errors.New("Read Length Error"))
+				m.frameLock = false
 			} else {
-				mk2.handleFrame(size, frame[0:int(size+1)])
+				m.handleFrame(size, frame[0:int(size+1)])
 			}
 		} else {
-			tmp := mk2.readByte()
+			tmp := m.readByte()
 			if tmp == 0xff || tmp == 0x20 {
-				l, err := io.ReadFull(mk2.p, frame[0:int(size)])
+				l, err := io.ReadFull(m.p, frame[0:int(size)])
 				if err != nil {
-					mk2.addError(fmt.Errorf("Read Error: %v", err))
+					m.addError(fmt.Errorf("Read Error: %v", err))
 					time.Sleep(1 * time.Second)
 				} else if l != int(size) {
-					mk2.addError(errors.New("Read Length Error"))
+					m.addError(errors.New("Read Length Error"))
 				} else {
 					if checkChecksum(size, tmp, frame[0:int(size)]) {
-						mk2.locked = true
+						m.frameLock = true
 						log.Printf("Locked")
 					}
 				}
@@ -90,109 +87,98 @@ func (mk2 *mk2Ser) frameLock() {
 }
 
 // Close Mk2
-func (mk2 *mk2Ser) Close() {
-	close(mk2.run)
-	mk2.wg.Wait()
+func (m *mk2Ser) Close() {
+	close(m.run)
+	m.wg.Wait()
 }
 
-// Returns last known state with all reported errors since previous poll.
-// Mk2Info.Valid will be false if no polling has completed.
-func (mk2 *mk2Ser) GetMk2Info() *Mk2Info {
-	mk2.RLock()
-	defer mk2.RUnlock()
-	return mk2.report
+func (m *mk2Ser) C() chan *Mk2Info {
+	return m.infochan
 }
 
-func (mk2 *mk2Ser) C() chan *Mk2Info {
-	return mk2.infochan
-}
-
-func (mk2 *mk2Ser) readByte() byte {
+func (m *mk2Ser) readByte() byte {
 	buffer := make([]byte, 1)
-	_, err := io.ReadFull(mk2.p, buffer)
+	_, err := io.ReadFull(m.p, buffer)
 	if err != nil {
-		mk2.addError(fmt.Errorf("Read error: %v", err))
+		m.addError(fmt.Errorf("Read error: %v", err))
 		return 0
 	}
 	return buffer[0]
 }
 
 // Adds error to error slice.
-func (mk2 *mk2Ser) addError(err error) {
-	if mk2.info.Errors == nil {
-		mk2.info.Errors = make([]error, 0)
+func (m *mk2Ser) addError(err error) {
+	if m.info.Errors == nil {
+		m.info.Errors = make([]error, 0)
 	}
-	mk2.info.Errors = append(mk2.info.Errors, err)
-	mk2.info.Valid = false
+	m.info.Errors = append(m.info.Errors, err)
+	m.info.Valid = false
 }
 
 // Updates report.
-func (mk2 *mk2Ser) updateReport() {
-	mk2.Lock()
-	defer mk2.Unlock()
-	mk2.info.Timestamp = time.Now()
-	mk2.report = mk2.info
+func (m *mk2Ser) updateReport() {
+	m.info.Timestamp = time.Now()
 	select {
-	case mk2.infochan <- mk2.info:
+	case m.infochan <- m.info:
 	default:
 	}
-	mk2.info = &Mk2Info{}
+	m.info = &Mk2Info{}
 }
 
 // Checks for valid frame and chooses decoding.
-func (mk2 *mk2Ser) handleFrame(l byte, frame []byte) {
+func (m *mk2Ser) handleFrame(l byte, frame []byte) {
 	if checkChecksum(l, frame[0], frame[1:]) {
 		switch frame[0] {
 		case 0xff:
 			switch frame[1] {
 			case 0x56: // V
-				mk2.versionDecode(frame[2:])
+				m.versionDecode(frame[2:])
 			case 0x57:
 				switch frame[2] {
 				case 0x8e:
-					mk2.scaleDecode(frame[2:])
+					m.scaleDecode(frame[2:])
 				case 0x85:
-					mk2.stateDecode(frame[2:])
+					m.stateDecode(frame[2:])
 				}
 
 			case 0x4C: // L
-				mk2.ledDecode(frame[2:])
+				m.ledDecode(frame[2:])
 			}
 
 		case 0x20:
 			switch frame[5] {
 			case 0x0C:
-				mk2.dcDecode(frame[1:])
+				m.dcDecode(frame[1:])
 			case 0x08:
-				mk2.acDecode(frame[1:])
+				m.acDecode(frame[1:])
 			}
 		}
 	} else {
-		log.Printf("Failed")
-		mk2.locked = false
+		log.Printf("Invalid incoming frame checksum: %x", frame)
+		m.frameLock = false
 	}
 }
 
 // Set the target VBus device.
-func (mk *mk2Ser) setTarget() {
+func (m *mk2Ser) setTarget() {
 	cmd := make([]byte, 3)
 	cmd[0] = 0x41 // A
 	cmd[1] = 0x01
 	cmd[2] = 0x00
-	mk.sendCommand(cmd)
+	m.sendCommand(cmd)
 }
 
 // Request the scaling factor for entry 'in'.
-func (mk *mk2Ser) reqScaleFactor(in byte) {
+func (m *mk2Ser) reqScaleFactor(in byte) {
 	cmd := make([]byte, 4)
 	cmd[0] = 0x57 // W
 	cmd[1] = 0x36
 	cmd[2] = in
-	mk.sendCommand(cmd)
+	m.sendCommand(cmd)
 }
 
 // Decode the scale factor frame.
-func (mk *mk2Ser) scaleDecode(frame []byte) {
+func (m *mk2Ser) scaleDecode(frame []byte) {
 	scl := uint16(frame[2])<<8 + uint16(frame[1])
 	ofs := int16(uint16(frame[5])<<8 + uint16(frame[4]))
 
@@ -203,11 +189,11 @@ func (mk *mk2Ser) scaleDecode(frame []byte) {
 	} else {
 		tmp.scale = math.Abs(float64(scl))
 	}
-	mk.sc = append(mk.sc, tmp)
+	m.scales = append(m.scales, tmp)
 
-	mk.scN++
-	if mk.scN < 14 {
-		mk.reqScaleFactor(byte(mk.scN))
+	m.scaleCount++
+	if m.scaleCount < 14 {
+		m.reqScaleFactor(byte(m.scaleCount))
 	} else {
 		log.Print("Monitoring starting.")
 	}
@@ -215,28 +201,28 @@ func (mk *mk2Ser) scaleDecode(frame []byte) {
 }
 
 // Decode the version number
-func (mk *mk2Ser) versionDecode(frame []byte) {
-	mk.info.Version = 0
-	mk.info.Valid = true
+func (m *mk2Ser) versionDecode(frame []byte) {
+	m.info.Version = 0
+	m.info.Valid = true
 	for i := 0; i < 4; i++ {
-		mk.info.Version += uint32(frame[i]) << uint(i) * 8
+		m.info.Version += uint32(frame[i]) << uint(i) * 8
 	}
 
-	if mk.scN < 14 {
+	if m.scaleCount < 14 {
 		log.Print("Get scaling factors.")
-		mk.reqScaleFactor(byte(mk.scN))
+		m.reqScaleFactor(byte(m.scaleCount))
 	} else {
 		// Send DC status request
 		cmd := make([]byte, 2)
 		cmd[0] = 0x46 //F
 		cmd[1] = 0
-		mk.sendCommand(cmd)
+		m.sendCommand(cmd)
 	}
 }
 
 // Apply scaling to float
-func (mk *mk2Ser) applyScale(value float64, scale int) float64 {
-	return mk.sc[scale].scale * (value + mk.sc[scale].offset)
+func (m *mk2Ser) applyScale(value float64, scale int) float64 {
+	return m.scales[scale].scale * (value + m.scales[scale].offset)
 }
 
 // Convert bytes->int16->float
@@ -250,57 +236,57 @@ func getUnsigned(data []byte) float64 {
 }
 
 // Decodes DC frame.
-func (mk *mk2Ser) dcDecode(frame []byte) {
-	mk.info.BatVoltage = mk.applyScale(getSigned(frame[5:7]), 4)
+func (m *mk2Ser) dcDecode(frame []byte) {
+	m.info.BatVoltage = m.applyScale(getSigned(frame[5:7]), 4)
 
-	usedC := mk.applyScale(getUnsigned(frame[7:10]), 5)
-	chargeC := mk.applyScale(getUnsigned(frame[10:13]), 5)
-	mk.info.BatCurrent = usedC - chargeC
+	usedC := m.applyScale(getUnsigned(frame[7:10]), 5)
+	chargeC := m.applyScale(getUnsigned(frame[10:13]), 5)
+	m.info.BatCurrent = usedC - chargeC
 
-	mk.info.OutFrequency = 10 / (mk.applyScale(float64(frame[13]), 7))
+	m.info.OutFrequency = 10 / (m.applyScale(float64(frame[13]), 7))
 
 	// Send L1 status request
 	cmd := make([]byte, 2)
 	cmd[0] = 0x46 //F
 	cmd[1] = 1
-	mk.sendCommand(cmd)
+	m.sendCommand(cmd)
 }
 
 // Decodes AC frame.
-func (mk *mk2Ser) acDecode(frame []byte) {
-	mk.info.InVoltage = mk.applyScale(getSigned(frame[5:7]), 0)
-	mk.info.InCurrent = mk.applyScale(getSigned(frame[7:9]), 1)
-	mk.info.OutVoltage = mk.applyScale(getSigned(frame[9:11]), 2)
-	mk.info.OutCurrent = mk.applyScale(getSigned(frame[11:13]), 3)
+func (m *mk2Ser) acDecode(frame []byte) {
+	m.info.InVoltage = m.applyScale(getSigned(frame[5:7]), 0)
+	m.info.InCurrent = m.applyScale(getSigned(frame[7:9]), 1)
+	m.info.OutVoltage = m.applyScale(getSigned(frame[9:11]), 2)
+	m.info.OutCurrent = m.applyScale(getSigned(frame[11:13]), 3)
 
 	if frame[13] == 0xff {
-		mk.info.InFrequency = 0
+		m.info.InFrequency = 0
 	} else {
-		mk.info.InFrequency = 10 / (mk.applyScale(float64(frame[13]), 8))
+		m.info.InFrequency = 10 / (m.applyScale(float64(frame[13]), 8))
 	}
 
 	// Send status request
 	cmd := make([]byte, 1)
 	cmd[0] = 0x4C //F
-	mk.sendCommand(cmd)
+	m.sendCommand(cmd)
 }
 
 // Decode charge state of battery.
-func (mk *mk2Ser) stateDecode(frame []byte) {
-	mk.info.ChargeState = mk.applyScale(getSigned(frame[1:3]), 13)
-	mk.updateReport()
+func (m *mk2Ser) stateDecode(frame []byte) {
+	m.info.ChargeState = m.applyScale(getSigned(frame[1:3]), 13)
+	m.updateReport()
 }
 
 // Decode the LED state frame.
-func (mk *mk2Ser) ledDecode(frame []byte) {
+func (m *mk2Ser) ledDecode(frame []byte) {
 
-	mk.info.LEDs = getLEDs(frame[0], frame[1])
+	m.info.LEDs = getLEDs(frame[0], frame[1])
 	// Send charge state request
 	cmd := make([]byte, 4)
 	cmd[0] = 0x57 //W
 	cmd[1] = 0x30
 	cmd[2] = 13
-	mk.sendCommand(cmd)
+	m.sendCommand(cmd)
 }
 
 // Adds active LEDs to list.
@@ -322,7 +308,7 @@ func getLEDs(ledsOn, ledsBlink byte) map[Led]LEDstate {
 }
 
 // Adds header and trailing crc for frame to send.
-func (mk2 *mk2Ser) sendCommand(data []byte) {
+func (m *mk2Ser) sendCommand(data []byte) {
 	l := len(data)
 	dataOut := make([]byte, l+3)
 	dataOut[0] = byte(l + 1)
@@ -334,9 +320,9 @@ func (mk2 *mk2Ser) sendCommand(data []byte) {
 	}
 	dataOut[l+2] = cr
 
-	_, err := mk2.p.Write(dataOut)
+	_, err := m.p.Write(dataOut)
 	if err != nil {
-		mk2.addError(fmt.Errorf("Write error: %v", err))
+		m.addError(fmt.Errorf("Write error: %v", err))
 	}
 }
 
@@ -346,8 +332,5 @@ func checkChecksum(l, t byte, d []byte) bool {
 	for i := 0; i < len(d); i++ {
 		cr = (cr + uint16(d[i])) % 256
 	}
-	if cr == 0 {
-		return true
-	}
-	return false
+	return cr == 0
 }
diff --git a/mk2if/mk2interface.go b/mk2if/mk2interface.go
index 8e662c9..b620e26 100644
--- a/mk2if/mk2interface.go
+++ b/mk2if/mk2interface.go
@@ -73,7 +73,6 @@ type Mk2Info struct {
 }
 
 type Mk2If interface {
-	GetMk2Info() *Mk2Info
 	C() chan *Mk2Info
 	Close()
 }
diff --git a/mk2if/mockmk2.go b/mk2if/mockmk2.go
new file mode 100644
index 0000000..0c64b5d
--- /dev/null
+++ b/mk2if/mockmk2.go
@@ -0,0 +1,71 @@
+package mk2if
+
+import (
+	"fmt"
+	"time"
+)
+
+type mock struct {
+	c chan *Mk2Info
+}
+
+func NewMk2Mock() Mk2If {
+	tmp := &mock{
+		c: make(chan *Mk2Info, 1),
+	}
+	go tmp.genMockValues()
+	return tmp
+}
+
+func genBaseLeds(state LEDstate) map[Led]LEDstate {
+	return map[Led]LEDstate{
+		LedMain:        state,
+		LedAbsorption:  state,
+		LedBulk:        state,
+		LedFloat:       state,
+		LedInverter:    state,
+		LedOverload:    state,
+		LedLowBattery:  state,
+		LedTemperature: state,
+	}
+}
+
+func (m *mock) C() chan *Mk2Info {
+	return m.c
+}
+
+func (m *mock) Close() {
+
+}
+
+func (m *mock) genMockValues() {
+	mult := 1.0
+	ledState := LedOff
+	for {
+		input := &Mk2Info{
+			OutCurrent:   2.0 * mult,
+			InCurrent:    2.3 * mult,
+			OutVoltage:   230.0 * mult,
+			InVoltage:    230.1 * mult,
+			BatVoltage:   25 * mult,
+			BatCurrent:   -10 * mult,
+			InFrequency:  50 * mult,
+			OutFrequency: 50 * mult,
+			ChargeState:  1 * mult,
+			Errors:       nil,
+			Timestamp:    time.Now(),
+			Valid:        true,
+			LEDs:         genBaseLeds(ledState),
+		}
+
+		ledState = (ledState + 1) % 3
+
+		mult = mult - 0.1
+		if mult < 0 {
+			mult = 1.0
+		}
+		fmt.Printf("Sending\n")
+		m.c <- input
+		time.Sleep(1 * time.Second)
+	}
+}
diff --git a/webgui/munin.go b/webgui/munin.go
index 161f09e..2e8c420 100644
--- a/webgui/munin.go
+++ b/webgui/munin.go
@@ -33,8 +33,9 @@ package webgui
 import (
 	"bytes"
 	"fmt"
-	"github.com/hpdvanwyk/invertergui/mk2if"
 	"net/http"
+
+	"github.com/hpdvanwyk/invertergui/mk2if"
 )
 
 type muninData struct {
@@ -46,7 +47,7 @@ func (w *WebGui) ServeMuninHTTP(rw http.ResponseWriter, r *http.Request) {
 	muninDat := <-w.muninRespChan
 	if muninDat.timesUpdated == 0 {
 		rw.WriteHeader(500)
-		rw.Write([]byte("No data to return.\n"))
+		_, _ = rw.Write([]byte("No data to return.\n"))
 		return
 	}
 	calcMuninAverages(&muninDat)
@@ -75,7 +76,7 @@ func (w *WebGui) ServeMuninHTTP(rw http.ResponseWriter, r *http.Request) {
 	fmt.Fprintf(outputBuf, "freqin.value %s\n", tmpInput.InFreq)
 	fmt.Fprintf(outputBuf, "freqout.value %s\n", tmpInput.OutFreq)
 
-	_, err := rw.Write([]byte(outputBuf.String()))
+	_, err := rw.Write(outputBuf.Bytes())
 	if err != nil {
 		fmt.Printf("%v\n", err)
 	}
@@ -171,7 +172,7 @@ freqout.label Out frequency (Hz)
 
 //Munin only samples once every 5 minutes so averages have to be calculated for some values.
 func calcMuninValues(muninDat *muninData, newStatus *mk2if.Mk2Info) {
-	muninDat.timesUpdated += 1
+	muninDat.timesUpdated++
 	muninVal := &muninDat.status
 	muninVal.OutCurrent += newStatus.OutCurrent
 	muninVal.InCurrent += newStatus.InCurrent
diff --git a/webgui/webgui.go b/webgui/webgui.go
index 3fea989..1c376a7 100644
--- a/webgui/webgui.go
+++ b/webgui/webgui.go
@@ -32,6 +32,7 @@ package webgui
 
 import (
 	"fmt"
+	"log"
 	"net/http"
 	"sync"
 	"time"
@@ -49,7 +50,6 @@ const (
 )
 
 type WebGui struct {
-	respChan chan *mk2if.Mk2Info
 	stopChan chan struct{}
 
 	muninRespChan chan muninData
@@ -178,14 +178,16 @@ func (w *WebGui) Stop() {
 func (w *WebGui) dataPoll() {
 	pollChan := w.poller.C()
 	var muninValues muninData
-	s := &mk2if.Mk2Info{}
 	for {
 		select {
-		case s = <-pollChan:
+		case s := <-pollChan:
 			if s.Valid {
 				calcMuninValues(&muninValues, s)
 				w.pu.updatePrometheus(s)
-				w.hub.Broadcast(buildTemplateInput(s))
+				err := w.hub.Broadcast(buildTemplateInput(s))
+				if err != nil {
+					log.Printf("Could not send update to clients: %v", err)
+				}
 			}
 		case w.muninRespChan <- muninValues:
 			zeroMuninValues(&muninValues)
diff --git a/webgui/webgui_test.go b/webgui/webgui_test.go
index dc7c019..17d16c8 100644
--- a/webgui/webgui_test.go
+++ b/webgui/webgui_test.go
@@ -32,10 +32,11 @@ package webgui
 
 import (
 	"fmt"
-	"github.com/hpdvanwyk/invertergui/mk2if"
 	"reflect"
 	"testing"
 	"time"
+
+	"github.com/hpdvanwyk/invertergui/mk2if"
 )
 
 func TestWebGui(t *testing.T) {
@@ -61,27 +62,28 @@ var templateInputTests = []templateTest{
 			InFrequency:  50,
 			OutFrequency: 50,
 			ChargeState:  1,
-			LedListOn:    []int{mk2if.LED_MAIN, mk2if.LED_FLOAT},
+			LEDs:         map[mk2if.Led]mk2if.LEDstate{mk2if.LedMain: mk2if.LedOn},
 			Errors:       nil,
 			Timestamp:    fakenow,
 		},
 		output: &templateInput{
 			Error:      nil,
 			Date:       fakenow.Format(time.RFC1123Z),
-			OutCurrent: "2.000",
-			OutVoltage: "230.000",
-			OutPower:   "460.000",
-			InCurrent:  "2.300",
-			InVoltage:  "230.100",
-			InPower:    "529.230",
-			InMinOut:   "69.230",
-			BatVoltage: "25.000",
-			BatCurrent: "-10.000",
-			BatPower:   "-250.000",
-			InFreq:     "50.000",
-			OutFreq:    "50.000",
-			BatCharge:  "100.000",
-			Leds:       []string{"Mains", "Float"}},
+			OutCurrent: "2.00",
+			OutVoltage: "230.00",
+			OutPower:   "460.00",
+			InCurrent:  "2.30",
+			InVoltage:  "230.10",
+			InPower:    "529.23",
+			InMinOut:   "69.23",
+			BatVoltage: "25.00",
+			BatCurrent: "-10.00",
+			BatPower:   "-250.00",
+			InFreq:     "50.00",
+			OutFreq:    "50.00",
+			BatCharge:  "100.00",
+			LedMap:     map[string]string{"led_mains": "dot-green"},
+		},
 	},
 }
 
diff --git a/websocket/client.go b/websocket/client.go
index d6f19a4..03d4af4 100644
--- a/websocket/client.go
+++ b/websocket/client.go
@@ -17,9 +17,6 @@ const (
 
 	// Send pings to peer with this period. Must be less than pongWait.
 	pingPeriod = (pongWait * 9) / 10
-
-	// Maximum message size allowed from peer.
-	maxMessageSize = 512
 )
 
 var upgrader = websocket.Upgrader{
@@ -52,10 +49,10 @@ func (c *Client) writePump() {
 	for {
 		select {
 		case message, ok := <-c.send:
-			c.conn.SetWriteDeadline(time.Now().Add(writeWait))
+			_ = c.conn.SetWriteDeadline(time.Now().Add(writeWait))
 			if !ok {
 				// The hub closed the channel.
-				c.conn.WriteMessage(websocket.CloseMessage, []byte{})
+				_ = c.conn.WriteMessage(websocket.CloseMessage, []byte{})
 				return
 			}
 
@@ -63,13 +60,13 @@ func (c *Client) writePump() {
 			if err != nil {
 				return
 			}
-			w.Write(message)
+			_, _ = w.Write(message)
 
 			if err := w.Close(); err != nil {
 				return
 			}
 		case <-ticker.C:
-			c.conn.SetWriteDeadline(time.Now().Add(writeWait))
+			_ = c.conn.SetWriteDeadline(time.Now().Add(writeWait))
 			if err := c.conn.WriteMessage(websocket.PingMessage, nil); err != nil {
 				return
 			}
diff --git a/websocket/hub.go b/websocket/hub.go
index fff0e27..f73a165 100644
--- a/websocket/hub.go
+++ b/websocket/hub.go
@@ -36,7 +36,7 @@ func (h *Hub) Broadcast(message interface{}) error {
 	if err != nil {
 		return err
 	}
-	h.broadcast <- []byte(payload)
+	h.broadcast <- payload
 	return nil
 }