examples: fix some missing checks of return errors

.circleci/config.yml

@@ -59,10 +59,27 @@ jobs:
             SOME=$(grep -L 'digispark' $(grep -L 'gocv' ${ALL}))
             for e in ${SOME} ; do go vet "${e}" ; done
 
+  "fmt_check_examples":
+    docker:
+      - image: golangci/golangci-lint:v1.55.2
+    steps:
+      - checkout
+      - run:
+          name: Debug linter version
+          command: golangci-lint --version
+      - run:
+          # digispark needs libusb, opencv needs opencv
+          name: Check examples (except digispark, opencv)
+          command: |
+            ALL=$(grep -l -r --include "*.go" 'build example' ./)
+            SOME=$(grep -L 'digispark' $(grep -L 'gocv' ${ALL}))
+            for e in ${SOME} ; do golangci-lint run "${e}" --build-tags example --disable forcetypeassert --disable noctx ; done
+
 workflows:
   version: 2
   build:
       jobs:
         - "test_core_and_drivers_with_coverage"
         - "test_platforms"
         - "check_examples"
+        - "fmt_check_examples"

Makefile

@@ -5,7 +5,7 @@ EXAMPLES_NO_GOCV := $(shell grep -L 'gocv' $(ALL_EXAMPLES))
 # used examples
 EXAMPLES := $(EXAMPLES_NO_GOCV)
 
-.PHONY: test test_race test_cover robeaux version_check fmt_check fmt_fix examples examples_check $(EXAMPLES)
+.PHONY: test test_race test_cover robeaux version_check fmt_check fmt_fix examples examples_check examples_fmt_fix $(EXAMPLES)
 
 # opencv platform currently skipped to prevent install of preconditions
 including_except := $(shell go list ./... | grep -v platforms/opencv)
@@ -65,9 +65,15 @@ examples: $(EXAMPLES)
 examples_check: 
 	$(MAKE) CHECK=ON examples
 
+examples_fmt_fix: 
+	$(MAKE) CHECK=FMT examples
+
 $(EXAMPLES):
 ifeq ($(CHECK),ON)
 	go vet ./$@
+else ifeq ($(CHECK),FMT)
+	gofumpt -l -w ./$@
+	golangci-lint run ./$@ --fix --build-tags example --disable forcetypeassert --disable noctx
 else
 	go build -o /tmp/gobot_examples/$@ ./$@
 endif

README.md

@@ -77,7 +77,9 @@ func main() {
 
   work := func() {
     gobot.Every(1*time.Second, func() {
-      led.Toggle()
+      if err := led.Toggle(); err != nil {
+				fmt.Println(err)
+			}
     })
   }
 
@@ -87,7 +89,9 @@ func main() {
     work,
   )
 
-  robot.Start()
+  if err := robot.Start(); err != nil {
+		panic(err)
+	}
 }
 ```
 
@@ -121,7 +125,9 @@ func main() {
     work,
   )
 
-  robot.Start()
+  if err := robot.Start(); err != nil {
+		panic(err)
+	}
 }
 ```
 
@@ -141,13 +147,19 @@ import (
 
 func main() {
   e := edison.NewAdaptor()
-  e.Connect()
+  if err := e.Connect(); err != nil {
+		fmt.Println(err)
+	}
 
   led := gpio.NewLedDriver(e, "13")
-  led.Start()
+  if err := led.Start(); err != nil {
+		fmt.Println(err)
+	}
 
   for {
-    led.Toggle()
+    if err := led.Toggle(); err != nil {
+				fmt.Println(err)
+			}
     time.Sleep(1000 * time.Millisecond)
   }
 }
@@ -179,7 +191,7 @@ func NewSwarmBot(port string) *gobot.Robot {
   work := func() {
     spheroDriver.Stop()
 
-    spheroDriver.On(sphero.CollisionEvent, func(data interface{}) {
+    _ = spheroDriver.On(sphero.CollisionEvent, func(data interface{}) {
       fmt.Println("Collision Detected!")
     })
 
@@ -218,7 +230,9 @@ func main() {
     master.AddRobot(NewSwarmBot(port))
   }
 
-  master.Start()
+  if err := master.Start(); err != nil {
+		panic(err)
+	}
 }
 ```
 

doc.go

@@ -27,7 +27,9 @@ Here is a "Classic Gobot" program that blinks an LED using an Arduino:
 
 	    work := func() {
 	        gobot.Every(1*time.Second, func() {
-	            led.Toggle()
+	            if err := led.Toggle(); err != nil {
+				fmt.Println(err)
+			}
 	        })
 	    }
 
@@ -37,7 +39,9 @@ Here is a "Classic Gobot" program that blinks an LED using an Arduino:
 	        work,
 	    )
 
-	    robot.Start()
+	    if err := robot.Start(); err != nil {
+				panic(err)
+			}
 	}
 
 # Metal Gobot
@@ -55,13 +59,19 @@ pure idiomatic Golang code. For example:
 
 	func main() {
 	    e := edison.NewAdaptor()
-	    e.Connect()
+	    if err := e.Connect(); err != nil {
+		fmt.Println(err)
+	}
 
 	    led := gpio.NewLedDriver(e, "13")
-	    led.Start()
+	    if err := led.Start(); err != nil {
+		fmt.Println(err)
+	}
 
 	    for {
-	        led.Toggle()
+	        if err := led.Toggle(); err != nil {
+				fmt.Println(err)
+			}
 	        time.Sleep(1000 * time.Millisecond)
 	    }
 	}
@@ -90,7 +100,7 @@ Finally, you can use Master Gobot to add the complete Gobot API or control swarm
 		    work := func() {
 		        spheroDriver.Stop()
 
-		        spheroDriver.On(sphero.CollisionEvent, func(data interface{}) {
+		        _ = spheroDriver.On(sphero.CollisionEvent, func(data interface{}) {
 		            fmt.Println("Collision Detected!")
 		        })
 
@@ -129,7 +139,9 @@ Finally, you can use Master Gobot to add the complete Gobot API or control swarm
 		        master.AddRobot(NewSwarmBot(port))
 		    }
 
-		    master.Start()
+		    if err := master.Start(); err != nil {
+		panic(err)
+	}
 		}
 
 Copyright (c) 2013-2018 The Hybrid Group. Licensed under the Apache 2.0 license.

drivers/MIGRATION.md

@@ -94,7 +94,7 @@ import(
   adaptor := sphero.NewAdaptor("/dev/rfcomm0")
   spheroDriver := sphero.NewSpheroDriver(adaptor)
 ...
-  spheroDriver.On(sphero.Collision, func(data interface{}) {
+  _ = spheroDriver.On(sphero.Collision, func(data interface{}) {
 ...
 
 // new
@@ -109,7 +109,7 @@ import(
   adaptor := serialport.NewAdaptor("/dev/rfcomm0")
   spheroDriver := serial.NewSpheroDriver(adaptor)
 ...
-  spheroDriver.On(sphero.CollisionEvent, func(data interface{}) {
+  _ = spheroDriver.On(sphero.CollisionEvent, func(data interface{}) {
 ...
 ```
 

examples/ardrone.go

@@ -18,7 +18,7 @@ func main() {
 	drone := ardrone.NewDriver(ardroneAdaptor)
 
 	work := func() {
-		drone.On(ardrone.Flying, func(data interface{}) {
+		_ = drone.On(ardrone.Flying, func(data interface{}) {
 			gobot.After(3*time.Second, func() {
 				drone.Land()
 			})
@@ -32,5 +32,7 @@ func main() {
 		work,
 	)
 
-	robot.Start()
+	if err := robot.Start(); err != nil {
+		panic(err)
+	}
 }

examples/ardrone_face_tracking.go

@@ -41,7 +41,7 @@ func main() {
 				window.WaitKey(1)
 			}
 		})
-		drone.On(ardrone.Flying, func(data interface{}) {
+		_ = drone.On(ardrone.Flying, func(data interface{}) {
 			gobot.After(1*time.Second, func() { drone.Up(0.2) })
 			gobot.After(2*time.Second, func() { drone.Hover() })
 			gobot.After(5*time.Second, func() {
@@ -83,5 +83,7 @@ func main() {
 		work,
 	)
 
-	robot.Start()
+	if err := robot.Start(); err != nil {
+		panic(err)
+	}
 }

examples/ardrone_ps3.go

@@ -37,34 +37,34 @@ func main() {
 	rightY.Store(float64(0.0))
 
 	work := func() {
-		stick.On(joystick.SquarePress, func(data interface{}) {
+		_ = stick.On(joystick.SquarePress, func(data interface{}) {
 			drone.TakeOff()
 		})
 
-		stick.On(joystick.TrianglePress, func(data interface{}) {
+		_ = stick.On(joystick.TrianglePress, func(data interface{}) {
 			drone.Hover()
 		})
 
-		stick.On(joystick.XPress, func(data interface{}) {
+		_ = stick.On(joystick.XPress, func(data interface{}) {
 			drone.Land()
 		})
 
-		stick.On(joystick.LeftX, func(data interface{}) {
+		_ = stick.On(joystick.LeftX, func(data interface{}) {
 			val := float64(data.(int16))
 			leftX.Store(val)
 		})
 
-		stick.On(joystick.LeftY, func(data interface{}) {
+		_ = stick.On(joystick.LeftY, func(data interface{}) {
 			val := float64(data.(int16))
 			leftY.Store(val)
 		})
 
-		stick.On(joystick.RightX, func(data interface{}) {
+		_ = stick.On(joystick.RightX, func(data interface{}) {
 			val := float64(data.(int16))
 			rightX.Store(val)
 		})
 
-		stick.On(joystick.RightY, func(data interface{}) {
+		_ = stick.On(joystick.RightY, func(data interface{}) {
 			val := float64(data.(int16))
 			rightY.Store(val)
 		})
@@ -120,7 +120,9 @@ func main() {
 		work,
 	)
 
-	robot.Start()
+	if err := robot.Start(); err != nil {
+		panic(err)
+	}
 }
 
 func getLeftStick() pair {

examples/audio.go

@@ -29,5 +29,7 @@ func main() {
 		work,
 	)
 
-	robot.Start()
+	if err := robot.Start(); err != nil {
+		panic(err)
+	}
 }

examples/batty.go

@@ -42,7 +42,9 @@ func main() {
 	})
 
 	gbot.AddRobot(r)
-	gbot.Start()
+	if err := gbot.Start(); err != nil {
+		fmt.Println(err)
+	}
 }
 
 var _ gobot.Adaptor = (*loopbackAdaptor)(nil)

examples/beaglebone_basic_direct_pin.go

@@ -7,6 +7,8 @@
 package main
 
 import (
+	"fmt"
+
 	"gobot.io/x/gobot/v2/drivers/gpio"
 	"gobot.io/x/gobot/v2/platforms/beaglebone"
 )
@@ -17,11 +19,15 @@ func main() {
 	gpioPin := gpio.NewDirectPinDriver(beagleboneAdaptor, "P9_12")
 
 	// Initialize the internal representation of the pinout
-	beagleboneAdaptor.Connect()
+	if err := beagleboneAdaptor.Connect(); err != nil {
+		fmt.Println(err)
+	}
 
 	// Cast to byte because we are returning an int from a function
 	// and not passing in an int literal.
-	gpioPin.DigitalWrite(byte(myStateFunction()))
+	if err := gpioPin.DigitalWrite(byte(myStateFunction())); err != nil {
+		fmt.Println(err)
+	}
 }
 
 // myStateFunction determines what the GPIO state should be

examples/beaglebone_blink.go

@@ -7,6 +7,7 @@
 package main
 
 import (
+	"fmt"
 	"time"
 
 	"gobot.io/x/gobot/v2"
@@ -20,7 +21,9 @@ func main() {
 
 	work := func() {
 		gobot.Every(1*time.Second, func() {
-			led.Toggle()
+			if err := led.Toggle(); err != nil {
+				fmt.Println(err)
+			}
 		})
 	}
 
@@ -30,5 +33,7 @@ func main() {
 		work,
 	)
 
-	robot.Start()
+	if err := robot.Start(); err != nil {
+		panic(err)
+	}
 }