Fix(build): linter findings of "gosimple", "govet" and "staticcheck" (h…

…ybridgroup#917)

Fix also encoder and dps overflow in gopigo3 "GetMotorStatus()". Problem found by "staticcheck".

.github/workflows/golangci-lint.yml

@@ -30,7 +30,8 @@ jobs:
           # working-directory: somedir
 
           # Optional: golangci-lint command line arguments.
-          # args: --issues-exit-code=0
+          # mostly there is no problem locally, but on server: "could not import C (cgo preprocessing failed) (typecheck)"
+          args: --skip-files platforms/digispark/littleWire.go
 
           # Optional: show only new issues if it's a pull request. The default value is `false`.
           # only-new-issues: true

.golangci.yml

@@ -36,8 +36,26 @@ linters:
   #       all issues step by step to enable at least the default linters
   disable:
     - errcheck
-    - gosimple
-    #- govet
     - ineffassign
-    - staticcheck
+    #- staticcheck
     - unused
+
+  enable:
+    - nolintlint
+
+linters-settings:
+  nolintlint:
+    # Enable to require an explanation of nonzero length after each nolint directive.
+    # Default: false
+    require-explanation: true
+    # Enable to require nolint directives to mention the specific linter being suppressed.
+    # Default: false
+    require-specific: true
+
+  revive:
+    rules:
+      # https://github.com/mgechev/revive/blob/master/RULES_DESCRIPTIONS.md#unexported-return
+      # disable this rule, because sometimes it has its justification
+      - name: unexported-return
+        severity: warning
+        disabled: true

api/api.go

@@ -109,15 +109,13 @@ func (a *API) Start() {
 
 // StartWithoutDefaults initializes the api without setting up the default routes.
 // Good for custom web interfaces.
-//
 func (a *API) StartWithoutDefaults() {
 	a.start(a)
 }
 
 // AddC3PIORoutes adds all of the standard C3PIO routes to the API.
 // For more information, please see:
 // http://cppp.io/
-//
 func (a *API) AddC3PIORoutes() {
 	mcpCommandRoute := "/api/commands/:command"
 	robotDeviceCommandRoute := "/api/robots/:robot/devices/:device/commands/:command"
@@ -250,10 +248,8 @@ func (a *API) robotDevice(res http.ResponseWriter, req *http.Request) {
 
 func (a *API) robotDeviceEvent(res http.ResponseWriter, req *http.Request) {
 	f, _ := res.(http.Flusher)
-	c, _ := res.(http.CloseNotifier)
 
 	dataChan := make(chan string)
-	closer := c.CloseNotify()
 
 	res.Header().Set("Content-Type", "text/event-stream")
 	res.Header().Set("Cache-Control", "no-cache")
@@ -275,7 +271,7 @@ func (a *API) robotDeviceEvent(res http.ResponseWriter, req *http.Request) {
 			case data := <-dataChan:
 				fmt.Fprintf(res, "data: %v\n\n", data)
 				f.Flush()
-			case <-closer:
+			case <-req.Context().Done():
 				log.Println("Closing connection")
 				return
 			}

api/api_test.go

@@ -81,7 +81,7 @@ func TestIndex(t *testing.T) {
 	a.ServeHTTP(response, request)
 
 	gobottest.Assert(t, http.StatusMovedPermanently, response.Code)
-	gobottest.Assert(t, "/index.html", response.HeaderMap["Location"][0])
+	gobottest.Assert(t, "/index.html", response.Header()["Location"][0])
 }
 
 func TestMcp(t *testing.T) {

cli/generate.go

@@ -30,7 +30,7 @@ func Generate() cli.Command {
 					valid = true
 				}
 			}
-			if valid == false {
+			if !valid {
 				fmt.Println("Invalid/no subcommand supplied.")
 				fmt.Println("Usage:")
 				fmt.Println(" gobot generate adaptor <name> [package] # generate a new Gobot adaptor")
@@ -102,7 +102,7 @@ func generate(c config, file string, tmpl string) error {
 	fmt.Println("Creating", fileLocation)
 
 	f, err := os.Create(fileLocation)
-	defer f.Close()
+	defer f.Close() //nolint:staticcheck // for historical reasons
 	if err != nil {
 		return err
 	}
@@ -149,11 +149,11 @@ func generatePlatform(c config) error {
 
 	c.dir = dir
 
-	if exp, err := ioutil.ReadFile(exampleDir + "/main.go"); err != nil {
+	exp, err := ioutil.ReadFile(exampleDir + "/main.go")
+	if err != nil {
 		return err
-	} else {
-		c.Example = string(exp)
 	}
+	c.Example = string(exp)
 
 	return generate(c, "README.md", readme())
 }

commander.go

@@ -22,10 +22,9 @@ func NewCommander() Commander {
 	}
 }
 
-// Command returns the command interface whene passed a valid command name
-func (c *commander) Command(name string) (command func(map[string]interface{}) interface{}) {
-	command, _ = c.commands[name]
-	return
+// Command returns the command interface when passed a valid command name
+func (c *commander) Command(name string) func(map[string]interface{}) interface{} {
+	return c.commands[name]
 }
 
 // Commands returns the entire map of valid commands

drivers/common/mfrc522/mfrc522_pcd.go

@@ -328,6 +328,9 @@ func (d *MFRC522Common) writeFifo(fifoData []byte) error {
 
 func (d *MFRC522Common) readFifo(backData []byte) (uint8, error) {
 	n, err := d.readByteData(regFIFOLevel) // Number of bytes in the FIFO
+	if err != nil {
+		return 0, err
+	}
 	if n > uint8(len(backData)) {
 		return 0, fmt.Errorf("more data in FIFO (%d) than expected (%d)", n, len(backData))
 	}

drivers/gpio/button_driver_test.go

@@ -35,7 +35,7 @@ func TestButtonDriver(t *testing.T) {
 }
 
 func TestButtonDriverStart(t *testing.T) {
-	sem := make(chan bool, 0)
+	sem := make(chan bool)
 	a := newGpioTestAdaptor()
 	d := NewButtonDriver(a, "1")
 
@@ -107,7 +107,7 @@ func TestButtonDriverStart(t *testing.T) {
 }
 
 func TestButtonDriverDefaultState(t *testing.T) {
-	sem := make(chan bool, 0)
+	sem := make(chan bool)
 	a := newGpioTestAdaptor()
 	d := NewButtonDriver(a, "1")
 	d.DefaultState = 1

drivers/gpio/pir_motion_driver_test.go

@@ -35,7 +35,7 @@ func TestPIRMotionDriver(t *testing.T) {
 }
 
 func TestPIRMotionDriverStart(t *testing.T) {
-	sem := make(chan bool, 0)
+	sem := make(chan bool)
 	a := newGpioTestAdaptor()
 	d := NewPIRMotionDriver(a, "1")
 

drivers/gpio/servo_driver.go

@@ -65,7 +65,7 @@ func (s *ServoDriver) Halt() (err error) { return }
 
 // Move sets the servo to the specified angle. Acceptable angles are 0-180
 func (s *ServoDriver) Move(angle uint8) (err error) {
-	if !(angle >= 0 && angle <= 180) {
+	if angle > 180 {
 		return ErrServoOutOfRange
 	}
 	s.CurrentAngle = angle

drivers/gpio/stepper_driver.go

@@ -111,7 +111,7 @@ func (s *StepperDriver) Start() (err error) { return }
 // Run continuously runs the stepper
 func (s *StepperDriver) Run() (err error) {
 	//halt if already moving
-	if s.moving == true {
+	if s.moving {
 		s.Halt()
 	}
 
@@ -123,7 +123,7 @@ func (s *StepperDriver) Run() (err error) {
 
 	go func() {
 		for {
-			if s.moving == false {
+			if !s.moving {
 				break
 			}
 			s.step()
@@ -191,7 +191,7 @@ func (s *StepperDriver) Move(stepsToMove int) error {
 		return s.Halt()
 	}
 
-	if s.moving == true {
+	if s.moving {
 		//stop previous motion
 		s.Halt()
 	}

drivers/gpio/stepper_driver_test.go

@@ -58,7 +58,7 @@ func TestStepperDriverDefaultDirection(t *testing.T) {
 func TestStepperDriverInvalidDirection(t *testing.T) {
 	d := initStepperMotorDriver()
 	err := d.SetDirection("reverse")
-	gobottest.Assert(t, err.(error), errors.New("Invalid direction. Value should be forward or backward"))
+	gobottest.Assert(t, err, errors.New("Invalid direction. Value should be forward or backward"))
 }
 
 func TestStepperDriverMoveForward(t *testing.T) {

drivers/i2c/ads1x15_driver.go

@@ -348,16 +348,12 @@ func (d *ADS1x15Driver) AnalogRead(pin string) (value int, err error) {
 	switch pin {
 	case "0-1":
 		channel = 0
-		break
 	case "0-3":
 		channel = 1
-		break
 	case "1-3":
 		channel = 2
-		break
 	case "2-3":
 		channel = 3
-		break
 	default:
 		// read the voltage at a specific pin, compared to the ground
 		channel, err = strconv.Atoi(pin)

drivers/i2c/ads1x15_driver_1015_test.go

@@ -103,7 +103,7 @@ func TestADS1015AnalogRead(t *testing.T) {
 	gobottest.Assert(t, val, 32767)
 	gobottest.Assert(t, err, nil)
 
-	val, err = d.AnalogRead("3-2")
+	_, err = d.AnalogRead("3-2")
 	gobottest.Refute(t, err.Error(), nil)
 }
 

drivers/i2c/ads1x15_driver_1115_test.go

@@ -103,7 +103,7 @@ func TestADS1115AnalogRead(t *testing.T) {
 	gobottest.Assert(t, val, 32767)
 	gobottest.Assert(t, err, nil)
 
-	val, err = d.AnalogRead("3-2")
+	_, err = d.AnalogRead("3-2")
 	gobottest.Refute(t, err.Error(), nil)
 }
 

drivers/i2c/ads1x15_driver_test.go

@@ -96,9 +96,9 @@ func TestADS1x15CommandsAnalogRead(t *testing.T) {
 }
 
 func TestADS1x15_ads1x15BestGainForVoltage(t *testing.T) {
-	g, err := ads1x15BestGainForVoltage(1.5)
+	g, _ := ads1x15BestGainForVoltage(1.5)
 	gobottest.Assert(t, g, 2)
 
-	g, err = ads1x15BestGainForVoltage(20.0)
+	_, err := ads1x15BestGainForVoltage(20.0)
 	gobottest.Assert(t, err, errors.New("The maximum voltage which can be read is 6.144000"))
 }

drivers/i2c/blinkm_driver_test.go

@@ -124,7 +124,7 @@ func TestBlinkMFirmwareVersion(t *testing.T) {
 		return 0, errors.New("write error")
 	}
 
-	version, err := d.FirmwareVersion()
+	_, err := d.FirmwareVersion()
 	gobottest.Assert(t, err, errors.New("write error"))
 }
 
@@ -152,7 +152,7 @@ func TestBlinkMColor(t *testing.T) {
 		return 0, errors.New("write error")
 	}
 
-	color, err := d.Color()
+	_, err := d.Color()
 	gobottest.Assert(t, err, errors.New("write error"))
 
 }

drivers/i2c/ccs811_driver.go

@@ -12,10 +12,10 @@ type CCS811DriveMode uint8
 // Operating modes which dictate how often measurements are being made. If 0x00 is used as an operating mode, measurements will be disabled
 const (
 	CCS811DriveModeIdle  CCS811DriveMode = 0x00
-	CCS811DriveMode1Sec                  = 0x01
-	CCS811DriveMode10Sec                 = 0x02
-	CCS811DriveMode60Sec                 = 0x03
-	CCS811DriveMode250MS                 = 0x04
+	CCS811DriveMode1Sec  CCS811DriveMode = 0x01
+	CCS811DriveMode10Sec CCS811DriveMode = 0x02
+	CCS811DriveMode60Sec CCS811DriveMode = 0x03
+	CCS811DriveMode250MS CCS811DriveMode = 0x04
 )
 
 const (

drivers/i2c/drv2605l_driver.go

@@ -6,13 +6,13 @@ type DRV2605Mode uint8
 // Operating modes, for use in SetMode()
 const (
 	DRV2605ModeIntTrig     DRV2605Mode = 0x00
-	DRV2605ModeExtTrigEdge             = 0x01
-	DRV2605ModeExtTrigLvl              = 0x02
-	DRV2605ModePWMAnalog               = 0x03
-	DRV2605ModeAudioVibe               = 0x04
-	DRV2605ModeRealtime                = 0x05
-	DRV2605ModeDiagnose                = 0x06
-	DRV2605ModeAutocal                 = 0x07
+	DRV2605ModeExtTrigEdge DRV2605Mode = 0x01
+	DRV2605ModeExtTrigLvl  DRV2605Mode = 0x02
+	DRV2605ModePWMAnalog   DRV2605Mode = 0x03
+	DRV2605ModeAudioVibe   DRV2605Mode = 0x04
+	DRV2605ModeRealtime    DRV2605Mode = 0x05
+	DRV2605ModeDiagnose    DRV2605Mode = 0x06
+	DRV2605ModeAutocal     DRV2605Mode = 0x07
 )
 
 const (

drivers/i2c/grovepi_driver.go

@@ -267,7 +267,7 @@ func (d *GrovePiDriver) SetPinMode(pin byte, mode string) error {
 func getPin(pin string) string {
 	if len(pin) > 1 {
 		if strings.ToUpper(pin[0:1]) == "A" || strings.ToUpper(pin[0:1]) == "D" {
-			return pin[1:len(pin)]
+			return pin[1:]
 		}
 	}
 

drivers/i2c/i2c_connection.go

@@ -30,7 +30,7 @@ type bitState uint8
 
 const (
 	clear bitState = 0x00
-	set            = 0x01
+	set   bitState = 0x01
 )
 
 // Connection is a connection to an I2C device with a specified address

drivers/i2c/mcp23017_driver_test.go

@@ -536,19 +536,19 @@ func TestMCP23017SetGPIOPolarityErr(t *testing.T) {
 
 func TestMCP23017_write(t *testing.T) {
 	// clear bit
-	d, a := initTestMCP23017WithStubbedAdaptor(0)
+	d, _ := initTestMCP23017WithStubbedAdaptor(0)
 	port := d.getPort("A")
 	err := d.write(port.IODIR, uint8(7), 0)
 	gobottest.Assert(t, err, nil)
 
 	// set bit
-	d, a = initTestMCP23017WithStubbedAdaptor(0)
+	d, _ = initTestMCP23017WithStubbedAdaptor(0)
 	port = d.getPort("B")
 	err = d.write(port.IODIR, uint8(7), 1)
 	gobottest.Assert(t, err, nil)
 
 	// write error
-	d, a = initTestMCP23017WithStubbedAdaptor(0)
+	d, a := initTestMCP23017WithStubbedAdaptor(0)
 	a.i2cWriteImpl = func([]byte) (int, error) {
 		return 0, errors.New("write error")
 	}

drivers/i2c/sht2x_driver.go

@@ -211,13 +211,13 @@ func (d *SHT2xDriver) initialize() error {
 	return nil
 }
 
-func (d *SHT2xDriver) sendAccuracy() (err error) {
-	if err = d.connection.WriteByte(SHT2xReadUserReg); err != nil {
-		return
+func (d *SHT2xDriver) sendAccuracy() error {
+	if err := d.connection.WriteByte(SHT2xReadUserReg); err != nil {
+		return err
 	}
 	userRegister, err := d.connection.ReadByte()
 	if err != nil {
-		return
+		return err
 	}
 
 	userRegister &= 0x7e //Turn off the resolution bits
@@ -226,15 +226,13 @@ func (d *SHT2xDriver) sendAccuracy() (err error) {
 	userRegister |= acc //Mask in the requested resolution bits
 
 	//Request a write to user register
-	_, err = d.connection.Write([]byte{SHT2xWriteUserReg, userRegister})
-	if err != nil {
-		return
+	if _, err := d.connection.Write([]byte{SHT2xWriteUserReg, userRegister}); err != nil {
+		return err
 	}
 
-	userRegister, err = d.connection.ReadByte()
-	if err != nil {
-		return
+	if _, err := d.connection.ReadByte(); err != nil {
+		return err
 	}
 
-	return
+	return nil
 }