staticcheck: enforce

This does result in a few awkward cases but in general it's worth
enforcing and most importantly will make my life as a code reviewer
easier.

It's mostly deletion of dead code.

.github/workflows/test.yml

@@ -93,8 +93,7 @@ jobs:
       run: ineffassign .
     - name: 'Check: staticcheck'
       if: always()
-      # TODO: Remove true if we make this check ever pass.
+      run: staticcheck -checks inherit,-SA1019 ./...
-      run: staticcheck ./... || true
     - name: 'Check: gosec (only G104)'
       run: gosec -include=G104 -fmt=golint -quiet ./...
 

ads1x15/ads1x15.go

@@ -370,7 +370,8 @@ const (
 var (
 	// Mapping of gain values to config register values.
 	gainConfig = map[int]uint16{
-		2 / 3: 0x0000,
+		// This value should be 2/3 but cannot be expressed as an integer.
+		0:  0x0000,
 		1:  0x0200,
 		2:  0x0400,
 		4:  0x0600,
@@ -378,7 +379,8 @@ var (
 		16: 0x0A00,
 	}
 	gainVoltage = map[int]physic.ElectricPotential{
-		2 / 3: 6144 * physic.MilliVolt,
+		// This value should be 2/3 but cannot be expressed as an integer.
+		0:  6144 * physic.MilliVolt,
 		1:  4096 * physic.MilliVolt,
 		2:  2048 * physic.MilliVolt,
 		4:  1024 * physic.MilliVolt,

as7262/as7262.go

@@ -153,7 +153,7 @@ func (d *Dev) Sense(ledDrive physic.ElectricCurrent, senseTime time.Duration) (S
 		return Spectrum{}, err
 	}
 
-	if err := d.writeVirtualRegister(ctx, controlReg, uint8(allOneShot)|uint8(d.gain)); err != nil {
+	if err := d.writeVirtualRegister(ctx, controlReg, allOneShot|uint8(d.gain)); err != nil {
 		return Spectrum{}, err
 	}
 
@@ -509,20 +509,11 @@ func calcLed(drive physic.ElectricCurrent) (uint8, physic.ElectricCurrent) {
 	}
 }
 
-type mode uint8
-
 const (
-	// Bank 1 consists of data from the V, G, B, Y photodiodes.
+	// allOneShot gets data from both banks once, and set the data ready bit in
-	bank1 mode = 0x00
-	// Bank 2 consists of data from the G, Y, O, R photodiodes.
-	bank2 mode = 0x04
-	// AllContinuously gets data from both banks continuously, requires 2x
-	// the integration time.
-	allContinuously mode = 0x08
-	// AllOneShot gets data from both banks once, and set the data ready bit in
 	// the status control register when complete requires 2x the integration
 	// time.
-	allOneShot mode = 0x0c
+	allOneShot uint8 = 0x0c
 )
 
 // IOError is a I/O specific error.

ep0099/ep0099.go

@@ -10,8 +10,8 @@ import (
 	"periph.io/x/conn/v3/i2c"
 )
 
-var errInvalidAddress = errors.New("Invalid EP-0099 address")
+var errInvalidAddress = errors.New("invalid EP-0099 address")
-var errInvalidChannel = errors.New("Invalid EP-0099 channel")
+var errInvalidChannel = errors.New("invalid EP-0099 channel")
 
 type State byte
 

ep0099/ep0099_test.go

@@ -108,11 +108,11 @@ func TestReturnErrorForInvalidChannel(t *testing.T) {
 }
 
 func TestStateToString(t *testing.T) {
-	if s := fmt.Sprintf("%s", StateOn); s != "on" {
+	if s := StateOn.String(); s != "on" {
 		t.Fatal("StateOn as string should be 'on', got ", s)
 	}
 
-	if s := fmt.Sprintf("%s", StateOff); s != "off" {
+	if s := StateOff.String(); s != "off" {
 		t.Fatal("StateOn as string should be 'off', got ", s)
 	}
 }

ina219/ina219_test.go

@@ -157,11 +157,6 @@ func TestNew(t *testing.T) {
 
 func TestSense(t *testing.T) {
 	stringErr := errors.New("use err.Error() error")
-	type fields struct {
-		currentLSB physic.ElectricCurrent
-		powerLSB   physic.Power
-	}
-
 	var tests = []struct {
 		name      string
 		args      Opts
@@ -291,7 +286,6 @@ func TestCalibrate(t *testing.T) {
 		maxCurrent physic.ElectricCurrent
 		currentLSB physic.ElectricCurrent
 		powerLSB   physic.Power
-		caibrated  bool
 	}
 	tests := []struct {
 		name      string

lepton/lepton.go

@@ -112,7 +112,6 @@ type Dev struct {
 	w          int
 	h          int
 	prevImg    *image14bit.Gray14
-	frameA, frameB []byte
 	frameWidth int // in bytes
 	frameLines int
 	maxTxSize  int

lirc/lirc.go

@@ -7,7 +7,6 @@ package lirc
 import (
 	"bufio"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"net"
 	"strconv"
@@ -15,7 +14,6 @@ import (
 	"sync"
 
 	"periph.io/x/conn/v3"
-	"periph.io/x/conn/v3/gpio/gpioreg"
 	"periph.io/x/conn/v3/ir"
 )
 
@@ -222,58 +220,5 @@ func read(r *bufio.Reader) (string, error) {
 	return string(raw), nil
 }
 
-// driver implements periph.Driver.
-type driver struct {
-}
-
-func (d *driver) String() string {
-	return "lirc"
-}
-
-func (d *driver) Init() (bool, error) {
-	in, out := getPins()
-	if in == -1 && out == -1 {
-		return false, nil
-	}
-	if in != -1 {
-		if err := gpioreg.RegisterAlias("IR_IN", strconv.Itoa(in)); err != nil {
-			return true, err
-		}
-	}
-	if out != -1 {
-		if err := gpioreg.RegisterAlias("IR_OUT", strconv.Itoa(out)); err != nil {
-			return true, err
-		}
-	}
-	return true, nil
-}
-
-// getPins queries the kernel module to determine which GPIO pins are taken by
-// the driver.
-//
-// The return values can be converted to bcm238x.Pin. Return (-1, -1) on
-// failure.
-func getPins() (int, int) {
-	// This is configured in /boot/config.txt as:
-	// dtoverlay=gpio_in_pin=23,gpio_out_pin=22
-	bytes, err := ioutil.ReadFile("/sys/module/lirc_rpi/parameters/gpio_in_pin")
-	if err != nil || len(bytes) == 0 {
-		return -1, -1
-	}
-	in, err := strconv.Atoi(strings.TrimRight(string(bytes), "\n"))
-	if err != nil {
-		return -1, -1
-	}
-	bytes, err = ioutil.ReadFile("/sys/module/lirc_rpi/parameters/gpio_out_pin")
-	if err != nil || len(bytes) == 0 {
-		return -1, -1
-	}
-	out, err := strconv.Atoi(strings.TrimRight(string(bytes), "\n"))
-	if err != nil {
-		return -1, -1
-	}
-	return in, out
-}
-
 var _ ir.Conn = &Conn{}
 var _ conn.Resource = &Conn{}

mcp23xxx/mcp23017_test.go

@@ -44,7 +44,6 @@ func TestMCP23017_out(t *testing.T) {
 }
 
 func TestMCP23S17_out(t *testing.T) {
-	const address uint16 = 0x20
 	scenario := &spitest.Playback{
 		Playback: conntest.Playback{
 			Ops: []conntest.IO{

mpu9250/spi.go

@@ -118,10 +118,6 @@ func (s *SpiTransport) readUint16(address ...byte) (uint16, error) {
 	return uint16(h)<<8 | uint16(l), nil
 }
 
-func (s *SpiTransport) printFunc(msg string, args ...interface{}) {
-	fmt.Printf("SPI: "+msg+"\n", args...)
-}
-
 func noop(string, ...interface{}) {}
 
 var _ Proto = &SpiTransport{}

nrzled/nrzled_spi_test.go

@@ -420,98 +420,6 @@ func TestSPI_Draw_DstEmpty(t *testing.T) {
 	}
 }
 
-var offsetDrawWant = []byte{
-	0x00, 0x00, 0x00, 0x00,
-	0xE1, 0x89, 0x79, 0x6B,
-	0xE1, 0x9A, 0x88, 0x75,
-	0xE1, 0xAD, 0x98, 0x82,
-	0xE1, 0xC2, 0xAB, 0x92,
-	0xE1, 0xDA, 0xC0, 0xA4,
-	0xE1, 0xF5, 0xD9, 0xB9,
-	0xE2, 0x89, 0x7A, 0x69,
-	0xE2, 0x9A, 0x8A, 0x76,
-	0xE2, 0xAC, 0x9B, 0x86,
-	0xE2, 0xC0, 0xAE, 0x98,
-	0xE2, 0xD5, 0xC3, 0xAC,
-	0xE2, 0xED, 0xDA, 0xC2,
-	0xE4, 0x83, 0x7A, 0x6E,
-	0x00, 0x00, 0x00, 0x00,
-	0x00, 0x00, 0x00, 0x00,
-	0xFF,
-}
-
-var offsetDrawTests = []struct {
-	name   string
-	img    image.Image
-	point  image.Point
-	offset image.Rectangle
-	want   []byte
-	opts   Opts
-}{
-	{
-		name: "Offset Draw NRGBA",
-		img: func() image.Image {
-			im := image.NewNRGBA(image.Rect(0, 0, 16, 4))
-			for x := 0; x < 16; x++ {
-				for y := 0; y < 4; y++ {
-					i := (y*16 + x) * 3
-					im.Set(x, y, color.RGBA{R: uint8(i + 1), G: uint8(i + 2), B: uint8(i + 3), A: 0xFF})
-				}
-			}
-			return im
-		}(),
-		point:  image.Point{X: 3, Y: 2},
-		offset: image.Rect(0, 0, 16, 1),
-		want:   offsetDrawWant,
-		opts: Opts{
-			NumPixels: 15,
-			Channels:  3,
-			Freq:      2500 * physic.KiloHertz,
-		},
-	},
-	{
-		name: "Both Offset Draw NRGBA",
-		img: func() image.Image {
-			im := image.NewNRGBA(image.Rect(0, 0, 16, 4))
-			for x := 0; x < 16; x++ {
-				for y := 0; y < 4; y++ {
-					i := (y*16 + x) * 3
-					im.Set(x, y, color.RGBA{R: uint8(i + 1), G: uint8(i + 2), B: uint8(i + 3), A: 0xFF})
-				}
-			}
-			return im
-		}(),
-		point:  image.Point{X: 3, Y: 2},
-		offset: image.Rect(2, 0, 16, 1),
-		want: []byte{
-			0x00, 0x00, 0x00, 0x00,
-			0x00, 0x00, 0x00, 0x00,
-			0x00, 0x00, 0x00, 0x00,
-			0xE1, 0x89, 0x79, 0x6B,
-			0xE1, 0x9A, 0x88, 0x75,
-			0xE1, 0xAD, 0x98, 0x82,
-			0xE1, 0xC2, 0xAB, 0x92,
-			0xE1, 0xDA, 0xC0, 0xA4,
-			0xE1, 0xF5, 0xD9, 0xB9,
-			0xE2, 0x89, 0x7A, 0x69,
-			0xE2, 0x9A, 0x8A, 0x76,
-			0xE2, 0xAC, 0x9B, 0x86,
-			0xE2, 0xC0, 0xAE, 0x98,
-			0xE2, 0xD5, 0xC3, 0xAC,
-			0xE2, 0xED, 0xDA, 0xC2,
-			0xE4, 0x83, 0x7A, 0x6E,
-			0x00, 0x00, 0x00, 0x00,
-			0x00, 0x00, 0x00, 0x00,
-			0xFF, 0xFF,
-		},
-		opts: Opts{
-			NumPixels: 17,
-			Channels:  3,
-			Freq:      2500 * physic.KiloHertz,
-		},
-	},
-}
-
 func TestSPI_Halt(t *testing.T) {
 	s := spitest.Playback{
 		Playback: conntest.Playback{
@@ -737,15 +645,3 @@ type limitLow struct {
 func (c *limitLow) MaxTxSize() int {
 	return 1
 }
-
-func equalUint16(a, b []uint16) bool {
-	if len(a) != len(b) {
-		return false
-	}
-	for i := range a {
-		if a[i] != b[i] {
-			return false
-		}
-	}
-	return true
-}

piblaster/piblaster.go

@@ -64,12 +64,3 @@ func openPiblaster() error {
 	}
 	return nil
 }
-
-func closePiblaster() error {
-	if piblasterHandle != nil {
-		w := piblasterHandle
-		piblasterHandle = nil
-		return w.Close()
-	}
-	return nil
-}

ssd1306/ssd1306_test.go

@@ -669,10 +669,6 @@ func initCmdI2C() []byte {
 	return append([]byte{0}, getInitCmd(&Opts{W: 128, H: 64, Rotated: false})...)
 }
 
-var preludeI2C = []byte{
-	0x0, 0x21, 0x0, 0x7f, 0x22, 0x0, 0x7,
-}
-
 func getI2CPlayback() *i2ctest.Playback {
 	return &i2ctest.Playback{
 		Ops: []i2ctest.IO{