diff --git a/README.md b/README.md
index b8cda7aab3..3820532e03 100644
--- a/README.md
+++ b/README.md
@@ -234,11 +234,6 @@ func init() {
 	rootCmd.AddCommand(initCmd)
 }
 
-func er(msg interface{}) {
-	fmt.Println("Error:", msg)
-	os.Exit(1)
-}
-
 func initConfig() {
 	if cfgFile != "" {
 		// Use config file from the flag.
@@ -246,9 +241,7 @@ func initConfig() {
 	} else {
 		// Find home directory.
 		home, err := homedir.Dir()
-		if err != nil {
-			er(err)
-		}
+		cobra.CheckErr(err)
 
 		// Search config in home directory with name ".cobra" (without extension).
 		viper.AddConfigPath(home)
diff --git a/bash_completions_test.go b/bash_completions_test.go
index fc455d8a31..21d1fe0eb8 100644
--- a/bash_completions_test.go
+++ b/bash_completions_test.go
@@ -51,7 +51,9 @@ func runShellCheck(s string) error {
 		return err
 	}
 	go func() {
-		stdin.Write([]byte(s))
+		_, err := stdin.Write([]byte(s))
+		CheckErr(err)
+
 		stdin.Close()
 	}()
 
@@ -73,26 +75,26 @@ func TestBashCompletions(t *testing.T) {
 		Run:                    emptyRun,
 	}
 	rootCmd.Flags().IntP("introot", "i", -1, "help message for flag introot")
-	rootCmd.MarkFlagRequired("introot")
+	assertNoErr(t, rootCmd.MarkFlagRequired("introot"))
 
 	// Filename.
 	rootCmd.Flags().String("filename", "", "Enter a filename")
-	rootCmd.MarkFlagFilename("filename", "json", "yaml", "yml")
+	assertNoErr(t, rootCmd.MarkFlagFilename("filename", "json", "yaml", "yml"))
 
 	// Persistent filename.
 	rootCmd.PersistentFlags().String("persistent-filename", "", "Enter a filename")
-	rootCmd.MarkPersistentFlagFilename("persistent-filename")
-	rootCmd.MarkPersistentFlagRequired("persistent-filename")
+	assertNoErr(t, rootCmd.MarkPersistentFlagFilename("persistent-filename"))
+	assertNoErr(t, rootCmd.MarkPersistentFlagRequired("persistent-filename"))
 
 	// Filename extensions.
 	rootCmd.Flags().String("filename-ext", "", "Enter a filename (extension limited)")
-	rootCmd.MarkFlagFilename("filename-ext")
+	assertNoErr(t, rootCmd.MarkFlagFilename("filename-ext"))
 	rootCmd.Flags().String("custom", "", "Enter a filename (extension limited)")
-	rootCmd.MarkFlagCustom("custom", "__complete_custom")
+	assertNoErr(t, rootCmd.MarkFlagCustom("custom", "__complete_custom"))
 
 	// Subdirectories in a given directory.
 	rootCmd.Flags().String("theme", "", "theme to use (located in /themes/THEMENAME/)")
-	rootCmd.Flags().SetAnnotation("theme", BashCompSubdirsInDir, []string{"themes"})
+	assertNoErr(t, rootCmd.Flags().SetAnnotation("theme", BashCompSubdirsInDir, []string{"themes"}))
 
 	// For two word flags check
 	rootCmd.Flags().StringP("two", "t", "", "this is two word flags")
@@ -108,9 +110,9 @@ func TestBashCompletions(t *testing.T) {
 	}
 
 	echoCmd.Flags().String("filename", "", "Enter a filename")
-	echoCmd.MarkFlagFilename("filename", "json", "yaml", "yml")
+	assertNoErr(t, echoCmd.MarkFlagFilename("filename", "json", "yaml", "yml"))
 	echoCmd.Flags().String("config", "", "config to use (located in /config/PROFILE/)")
-	echoCmd.Flags().SetAnnotation("config", BashCompSubdirsInDir, []string{"config"})
+	assertNoErr(t, echoCmd.Flags().SetAnnotation("config", BashCompSubdirsInDir, []string{"config"}))
 
 	printCmd := &Command{
 		Use:   "print [string to print]",
@@ -148,7 +150,7 @@ func TestBashCompletions(t *testing.T) {
 	rootCmd.AddCommand(echoCmd, printCmd, deprecatedCmd, colonCmd)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenBashCompletion(buf)
+	assertNoErr(t, rootCmd.GenBashCompletion(buf))
 	output := buf.String()
 
 	check(t, output, "_root")
@@ -215,10 +217,10 @@ func TestBashCompletionHiddenFlag(t *testing.T) {
 
 	const flagName = "hiddenFlag"
 	c.Flags().Bool(flagName, false, "")
-	c.Flags().MarkHidden(flagName)
+	assertNoErr(t, c.Flags().MarkHidden(flagName))
 
 	buf := new(bytes.Buffer)
-	c.GenBashCompletion(buf)
+	assertNoErr(t, c.GenBashCompletion(buf))
 	output := buf.String()
 
 	if strings.Contains(output, flagName) {
@@ -231,10 +233,10 @@ func TestBashCompletionDeprecatedFlag(t *testing.T) {
 
 	const flagName = "deprecated-flag"
 	c.Flags().Bool(flagName, false, "")
-	c.Flags().MarkDeprecated(flagName, "use --not-deprecated instead")
+	assertNoErr(t, c.Flags().MarkDeprecated(flagName, "use --not-deprecated instead"))
 
 	buf := new(bytes.Buffer)
-	c.GenBashCompletion(buf)
+	assertNoErr(t, c.GenBashCompletion(buf))
 	output := buf.String()
 
 	if strings.Contains(output, flagName) {
@@ -249,7 +251,7 @@ func TestBashCompletionTraverseChildren(t *testing.T) {
 	c.Flags().BoolP("bool-flag", "b", false, "bool flag")
 
 	buf := new(bytes.Buffer)
-	c.GenBashCompletion(buf)
+	assertNoErr(t, c.GenBashCompletion(buf))
 	output := buf.String()
 
 	// check that local nonpersistent flag are not set since we have TraverseChildren set to true
diff --git a/cobra.go b/cobra.go
index d01becc8fa..bd7e372cce 100644
--- a/cobra.go
+++ b/cobra.go
@@ -19,6 +19,7 @@ package cobra
 import (
 	"fmt"
 	"io"
+	"os"
 	"reflect"
 	"strconv"
 	"strings"
@@ -205,3 +206,11 @@ func stringInSlice(a string, list []string) bool {
 	}
 	return false
 }
+
+// CheckErr prints the msg with the prefix 'Error:' and exits with error code 1. If the msg is nil, it does nothing.
+func CheckErr(msg interface{}) {
+	if msg != nil {
+		fmt.Fprintln(os.Stderr, "Error:", msg)
+		os.Exit(1)
+	}
+}
diff --git a/cobra/cmd/add.go b/cobra/cmd/add.go
index 6645a755f0..8377411edd 100644
--- a/cobra/cmd/add.go
+++ b/cobra/cmd/add.go
@@ -40,13 +40,11 @@ Example: cobra add server -> resulting in a new cmd/server.go`,
 
 		Run: func(cmd *cobra.Command, args []string) {
 			if len(args) < 1 {
-				er("add needs a name for the command")
+				cobra.CheckErr(fmt.Errorf("add needs a name for the command"))
 			}
 
 			wd, err := os.Getwd()
-			if err != nil {
-				er(err)
-			}
+			cobra.CheckErr(err)
 
 			commandName := validateCmdName(args[0])
 			command := &Command{
@@ -59,10 +57,7 @@ Example: cobra add server -> resulting in a new cmd/server.go`,
 				},
 			}
 
-			err = command.Create()
-			if err != nil {
-				er(err)
-			}
+			cobra.CheckErr(command.Create())
 
 			fmt.Printf("%s created at %s\n", command.CmdName, command.AbsolutePath)
 		},
@@ -72,7 +67,7 @@ Example: cobra add server -> resulting in a new cmd/server.go`,
 func init() {
 	addCmd.Flags().StringVarP(&packageName, "package", "t", "", "target package name (e.g. github.com/spf13/hugo)")
 	addCmd.Flags().StringVarP(&parentName, "parent", "p", "rootCmd", "variable name of parent command for this command")
-	addCmd.Flags().MarkDeprecated("package", "this operation has been removed.")
+	cobra.CheckErr(addCmd.Flags().MarkDeprecated("package", "this operation has been removed."))
 }
 
 // validateCmdName returns source without any dashes and underscore.
diff --git a/cobra/cmd/add_test.go b/cobra/cmd/add_test.go
index de92fcea66..0b32ca67e5 100644
--- a/cobra/cmd/add_test.go
+++ b/cobra/cmd/add_test.go
@@ -14,10 +14,8 @@ func TestGoldenAddCmd(t *testing.T) {
 	}
 	defer os.RemoveAll(command.AbsolutePath)
 
-	command.Project.Create()
-	if err := command.Create(); err != nil {
-		t.Fatal(err)
-	}
+	assertNoErr(t, command.Project.Create())
+	assertNoErr(t, command.Create())
 
 	generatedFile := fmt.Sprintf("%s/cmd/%s.go", command.AbsolutePath, command.CmdName)
 	goldenFile := fmt.Sprintf("testdata/%s.go.golden", command.CmdName)
diff --git a/cobra/cmd/helpers.go b/cobra/cmd/helpers.go
index 4a5900d21f..6a8047e38b 100644
--- a/cobra/cmd/helpers.go
+++ b/cobra/cmd/helpers.go
@@ -14,11 +14,12 @@
 package cmd
 
 import (
-	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"strings"
+
+	"github.com/spf13/cobra"
 )
 
 var srcPaths []string
@@ -40,14 +41,12 @@ func init() {
 		}
 
 		out, err := exec.Command(goExecutable, "env", "GOPATH").Output()
-		if err != nil {
-			er(err)
-		}
+		cobra.CheckErr(err)
 
 		toolchainGoPath := strings.TrimSpace(string(out))
 		goPaths = filepath.SplitList(toolchainGoPath)
 		if len(goPaths) == 0 {
-			er("$GOPATH is not set")
+			cobra.CheckErr("$GOPATH is not set")
 		}
 	}
 	srcPaths = make([]string, 0, len(goPaths))
@@ -55,8 +54,3 @@ func init() {
 		srcPaths = append(srcPaths, filepath.Join(goPath, "src"))
 	}
 }
-
-func er(msg interface{}) {
-	fmt.Println("Error:", msg)
-	os.Exit(1)
-}
diff --git a/cobra/cmd/helpers_test.go b/cobra/cmd/helpers_test.go
new file mode 100644
index 0000000000..c5d20026cf
--- /dev/null
+++ b/cobra/cmd/helpers_test.go
@@ -0,0 +1,9 @@
+package cmd
+
+import "testing"
+
+func assertNoErr(t *testing.T, e error) {
+	if e != nil {
+		t.Error(e)
+	}
+}
diff --git a/cobra/cmd/init.go b/cobra/cmd/init.go
index 504a47850e..8c0e617abf 100644
--- a/cobra/cmd/init.go
+++ b/cobra/cmd/init.go
@@ -39,9 +39,7 @@ and the appropriate structure for a Cobra-based CLI application.
 		Run: func(_ *cobra.Command, args []string) {
 
 			projectPath, err := initializeProject(args)
-			if err != nil {
-				er(err)
-			}
+			cobra.CheckErr(err)
 			fmt.Printf("Your Cobra application is ready at\n%s\n", projectPath)
 		},
 	}
@@ -49,7 +47,7 @@ and the appropriate structure for a Cobra-based CLI application.
 
 func init() {
 	initCmd.Flags().StringVar(&pkgName, "pkg-name", "", "fully qualified pkg name")
-	initCmd.MarkFlagRequired("pkg-name")
+	cobra.CheckErr(initCmd.MarkFlagRequired("pkg-name"))
 }
 
 func initializeProject(args []string) (string, error) {
diff --git a/cobra/cmd/init_test.go b/cobra/cmd/init_test.go
index c4b3f09a21..6d21ef7730 100644
--- a/cobra/cmd/init_test.go
+++ b/cobra/cmd/init_test.go
@@ -59,7 +59,7 @@ func TestGoldenInitCmd(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 
-			initCmd.Flags().Set("pkg-name", tt.pkgName)
+			assertNoErr(t, initCmd.Flags().Set("pkg-name", tt.pkgName))
 			viper.Set("useViper", true)
 			projectPath, err := initializeProject(tt.args)
 			defer func() {
diff --git a/cobra/cmd/licenses.go b/cobra/cmd/licenses.go
index a070134ddc..2b3a424389 100644
--- a/cobra/cmd/licenses.go
+++ b/cobra/cmd/licenses.go
@@ -16,9 +16,11 @@
 package cmd
 
 import (
+	"fmt"
 	"strings"
 	"time"
 
+	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 )
 
@@ -92,7 +94,7 @@ func copyrightLine() string {
 func findLicense(name string) License {
 	found := matchLicense(name)
 	if found == "" {
-		er("unknown license: " + name)
+		cobra.CheckErr(fmt.Errorf("unknown license: " + name))
 	}
 	return Licenses[found]
 }
diff --git a/cobra/cmd/project.go b/cobra/cmd/project.go
index ecd783d030..bd68a31d78 100644
--- a/cobra/cmd/project.go
+++ b/cobra/cmd/project.go
@@ -5,6 +5,7 @@ import (
 	"os"
 	"text/template"
 
+	"github.com/spf13/cobra"
 	"github.com/spf13/cobra/cobra/tpl"
 )
 
@@ -49,7 +50,7 @@ func (p *Project) Create() error {
 
 	// create cmd/root.go
 	if _, err = os.Stat(fmt.Sprintf("%s/cmd", p.AbsolutePath)); os.IsNotExist(err) {
-		os.Mkdir(fmt.Sprintf("%s/cmd", p.AbsolutePath), 0751)
+		cobra.CheckErr(os.Mkdir(fmt.Sprintf("%s/cmd", p.AbsolutePath), 0751))
 	}
 	rootFile, err := os.Create(fmt.Sprintf("%s/cmd/root.go", p.AbsolutePath))
 	if err != nil {
diff --git a/cobra/cmd/root.go b/cobra/cmd/root.go
index 97f404bbb6..f27ae7e6cf 100644
--- a/cobra/cmd/root.go
+++ b/cobra/cmd/root.go
@@ -47,8 +47,8 @@ func init() {
 	rootCmd.PersistentFlags().StringP("author", "a", "YOUR NAME", "author name for copyright attribution")
 	rootCmd.PersistentFlags().StringVarP(&userLicense, "license", "l", "", "name of license for the project")
 	rootCmd.PersistentFlags().Bool("viper", true, "use Viper for configuration")
-	viper.BindPFlag("author", rootCmd.PersistentFlags().Lookup("author"))
-	viper.BindPFlag("useViper", rootCmd.PersistentFlags().Lookup("viper"))
+	cobra.CheckErr(viper.BindPFlag("author", rootCmd.PersistentFlags().Lookup("author")))
+	cobra.CheckErr(viper.BindPFlag("useViper", rootCmd.PersistentFlags().Lookup("viper")))
 	viper.SetDefault("author", "NAME HERE <EMAIL ADDRESS>")
 	viper.SetDefault("license", "apache")
 
@@ -63,9 +63,7 @@ func initConfig() {
 	} else {
 		// Find home directory.
 		home, err := homedir.Dir()
-		if err != nil {
-			er(err)
-		}
+		cobra.CheckErr(err)
 
 		// Search config in home directory with name ".cobra" (without extension).
 		viper.AddConfigPath(home)
diff --git a/cobra/cmd/testdata/root.go.golden b/cobra/cmd/testdata/root.go.golden
index 9a554a7c13..dba491123b 100644
--- a/cobra/cmd/testdata/root.go.golden
+++ b/cobra/cmd/testdata/root.go.golden
@@ -44,10 +44,7 @@ to quickly create a Cobra application.`,
 // Execute adds all child commands to the root command and sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.
 func Execute() {
-	if err := rootCmd.Execute(); err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
-	}
+	cobra.CheckErr(rootCmd.Execute())
 }
 
 func init() {
@@ -72,10 +69,7 @@ func initConfig() {
 	} else {
 		// Find home directory.
 		home, err := homedir.Dir()
-		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(1)
-		}
+		cobra.CheckErr(err)
 
 		// Search config in home directory with name ".testproject" (without extension).
 		viper.AddConfigPath(home)
diff --git a/cobra/tpl/main.go b/cobra/tpl/main.go
index 59daa00bfc..0b9c6610e3 100644
--- a/cobra/tpl/main.go
+++ b/cobra/tpl/main.go
@@ -53,10 +53,7 @@ to quickly create a Cobra application.` + "`" + `,
 // Execute adds all child commands to the root command and sets flags appropriately.
 // This is called by main.main(). It only needs to happen once to the rootCmd.
 func Execute() {
-	if err := rootCmd.Execute(); err != nil {
-		fmt.Fprintln(os.Stderr, err)
-		os.Exit(1)
-	}
+	cobra.CheckErr(rootCmd.Execute())
 }
 
 func init() {
@@ -85,10 +82,7 @@ func initConfig() {
 	} else {
 		// Find home directory.
 		home, err := homedir.Dir()
-		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(1)
-		}
+		cobra.CheckErr(err)
 
 		// Search config in home directory with name ".{{ .AppName }}" (without extension).
 		viper.AddConfigPath(home)
diff --git a/cobra_test.go b/cobra_test.go
index 0d1755bdba..1219cc0792 100644
--- a/cobra_test.go
+++ b/cobra_test.go
@@ -5,6 +5,12 @@ import (
 	"text/template"
 )
 
+func assertNoErr(t *testing.T, e error) {
+	if e != nil {
+		t.Error(e)
+	}
+}
+
 func TestAddTemplateFunctions(t *testing.T) {
 	AddTemplateFunc("t", func() bool { return true })
 	AddTemplateFuncs(template.FuncMap{
diff --git a/command.go b/command.go
index 42d2ced42c..9c58006e10 100644
--- a/command.go
+++ b/command.go
@@ -420,7 +420,7 @@ func (c *Command) UsageString() string {
 	c.outWriter = bb
 	c.errWriter = bb
 
-	c.Usage()
+	CheckErr(c.Usage())
 
 	// Setting things back to normal
 	c.outWriter = tmpOutput
@@ -1089,10 +1089,10 @@ Simply type ` + c.Name() + ` help [path to command] for full details.`,
 				cmd, _, e := c.Root().Find(args)
 				if cmd == nil || e != nil {
 					c.Printf("Unknown help topic %#q\n", args)
-					c.Root().Usage()
+					CheckErr(c.Root().Usage())
 				} else {
 					cmd.InitDefaultHelpFlag() // make possible 'help' flag to be shown
-					cmd.Help()
+					CheckErr(cmd.Help())
 				}
 			},
 		}
diff --git a/command_test.go b/command_test.go
index 924228db42..9640fc5dce 100644
--- a/command_test.go
+++ b/command_test.go
@@ -737,9 +737,9 @@ func TestPersistentFlagsOnChild(t *testing.T) {
 func TestRequiredFlags(t *testing.T) {
 	c := &Command{Use: "c", Run: emptyRun}
 	c.Flags().String("foo1", "", "")
-	c.MarkFlagRequired("foo1")
+	assertNoErr(t, c.MarkFlagRequired("foo1"))
 	c.Flags().String("foo2", "", "")
-	c.MarkFlagRequired("foo2")
+	assertNoErr(t, c.MarkFlagRequired("foo2"))
 	c.Flags().String("bar", "", "")
 
 	expected := fmt.Sprintf("required flag(s) %q, %q not set", "foo1", "foo2")
@@ -755,16 +755,16 @@ func TestRequiredFlags(t *testing.T) {
 func TestPersistentRequiredFlags(t *testing.T) {
 	parent := &Command{Use: "parent", Run: emptyRun}
 	parent.PersistentFlags().String("foo1", "", "")
-	parent.MarkPersistentFlagRequired("foo1")
+	assertNoErr(t, parent.MarkPersistentFlagRequired("foo1"))
 	parent.PersistentFlags().String("foo2", "", "")
-	parent.MarkPersistentFlagRequired("foo2")
+	assertNoErr(t, parent.MarkPersistentFlagRequired("foo2"))
 	parent.Flags().String("foo3", "", "")
 
 	child := &Command{Use: "child", Run: emptyRun}
 	child.Flags().String("bar1", "", "")
-	child.MarkFlagRequired("bar1")
+	assertNoErr(t, child.MarkFlagRequired("bar1"))
 	child.Flags().String("bar2", "", "")
-	child.MarkFlagRequired("bar2")
+	assertNoErr(t, child.MarkFlagRequired("bar2"))
 	child.Flags().String("bar3", "", "")
 
 	parent.AddCommand(child)
@@ -784,7 +784,7 @@ func TestPersistentRequiredFlagsWithDisableFlagParsing(t *testing.T) {
 	parent := &Command{Use: "parent", Run: emptyRun}
 	parent.PersistentFlags().Bool("foo", false, "")
 	flag := parent.PersistentFlags().Lookup("foo")
-	parent.MarkPersistentFlagRequired("foo")
+	assertNoErr(t, parent.MarkPersistentFlagRequired("foo"))
 
 	child := &Command{Use: "child", Run: emptyRun}
 	child.DisableFlagParsing = true
@@ -1729,7 +1729,7 @@ func TestMergeCommandLineToFlags(t *testing.T) {
 func TestUseDeprecatedFlags(t *testing.T) {
 	c := &Command{Use: "c", Run: emptyRun}
 	c.Flags().BoolP("deprecated", "d", false, "deprecated flag")
-	c.Flags().MarkDeprecated("deprecated", "This flag is deprecated")
+	assertNoErr(t, c.Flags().MarkDeprecated("deprecated", "This flag is deprecated"))
 
 	output, err := executeCommand(c, "c", "-d")
 	if err != nil {
@@ -1877,7 +1877,7 @@ func (tc *calledAsTestcase) test(t *testing.T) {
 	parent.SetOut(output)
 	parent.SetErr(output)
 
-	parent.Execute()
+	_ = parent.Execute()
 
 	if called == nil {
 		if tc.call != "" {
diff --git a/custom_completions.go b/custom_completions.go
index f9e88e081f..d1ee694840 100644
--- a/custom_completions.go
+++ b/custom_completions.go
@@ -527,13 +527,14 @@ func CompDebug(msg string, printToStdErr bool) {
 			os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
 		if err == nil {
 			defer f.Close()
-			f.WriteString(msg)
+			_, err := f.WriteString(msg)
+			CheckErr(err)
 		}
 	}
 
 	if printToStdErr {
 		// Must print to stderr for this not to be read by the completion script.
-		fmt.Fprintf(os.Stderr, msg)
+		fmt.Fprint(os.Stderr, msg)
 	}
 }
 
diff --git a/custom_completions_test.go b/custom_completions_test.go
index 14ec5a9eb6..ede809ed43 100644
--- a/custom_completions_test.go
+++ b/custom_completions_test.go
@@ -780,17 +780,17 @@ func TestRequiredFlagNameCompletionInGo(t *testing.T) {
 	rootCmd.AddCommand(childCmd)
 
 	rootCmd.Flags().IntP("requiredFlag", "r", -1, "required flag")
-	rootCmd.MarkFlagRequired("requiredFlag")
+	assertNoErr(t, rootCmd.MarkFlagRequired("requiredFlag"))
 	requiredFlag := rootCmd.Flags().Lookup("requiredFlag")
 
 	rootCmd.PersistentFlags().IntP("requiredPersistent", "p", -1, "required persistent")
-	rootCmd.MarkPersistentFlagRequired("requiredPersistent")
+	assertNoErr(t, rootCmd.MarkPersistentFlagRequired("requiredPersistent"))
 	requiredPersistent := rootCmd.PersistentFlags().Lookup("requiredPersistent")
 
 	rootCmd.Flags().StringP("release", "R", "", "Release name")
 
 	childCmd.Flags().BoolP("subRequired", "s", false, "sub required flag")
-	childCmd.MarkFlagRequired("subRequired")
+	assertNoErr(t, childCmd.MarkFlagRequired("subRequired"))
 	childCmd.Flags().BoolP("subNotRequired", "n", false, "sub not required flag")
 
 	// Test that a required flag is suggested even without the - prefix
@@ -964,19 +964,19 @@ func TestFlagFileExtFilterCompletionInGo(t *testing.T) {
 
 	// No extensions.  Should be ignored.
 	rootCmd.Flags().StringP("file", "f", "", "file flag")
-	rootCmd.MarkFlagFilename("file")
+	assertNoErr(t, rootCmd.MarkFlagFilename("file"))
 
 	// Single extension
 	rootCmd.Flags().StringP("log", "l", "", "log flag")
-	rootCmd.MarkFlagFilename("log", "log")
+	assertNoErr(t, rootCmd.MarkFlagFilename("log", "log"))
 
 	// Multiple extensions
 	rootCmd.Flags().StringP("yaml", "y", "", "yaml flag")
-	rootCmd.MarkFlagFilename("yaml", "yaml", "yml")
+	assertNoErr(t, rootCmd.MarkFlagFilename("yaml", "yaml", "yml"))
 
 	// Directly using annotation
 	rootCmd.Flags().StringP("text", "t", "", "text flag")
-	rootCmd.Flags().SetAnnotation("text", BashCompFilenameExt, []string{"txt"})
+	assertNoErr(t, rootCmd.Flags().SetAnnotation("text", BashCompFilenameExt, []string{"txt"}))
 
 	// Test that the completion logic returns the proper info for the completion
 	// script to handle the file filtering
@@ -1086,15 +1086,15 @@ func TestFlagDirFilterCompletionInGo(t *testing.T) {
 
 	// Filter directories
 	rootCmd.Flags().StringP("dir", "d", "", "dir flag")
-	rootCmd.MarkFlagDirname("dir")
+	assertNoErr(t, rootCmd.MarkFlagDirname("dir"))
 
 	// Filter directories within a directory
 	rootCmd.Flags().StringP("subdir", "s", "", "subdir")
-	rootCmd.Flags().SetAnnotation("subdir", BashCompSubdirsInDir, []string{"themes"})
+	assertNoErr(t, rootCmd.Flags().SetAnnotation("subdir", BashCompSubdirsInDir, []string{"themes"}))
 
 	// Multiple directory specification get ignored
 	rootCmd.Flags().StringP("manydir", "m", "", "manydir")
-	rootCmd.Flags().SetAnnotation("manydir", BashCompSubdirsInDir, []string{"themes", "colors"})
+	assertNoErr(t, rootCmd.Flags().SetAnnotation("manydir", BashCompSubdirsInDir, []string{"themes", "colors"}))
 
 	// Test that the completion logic returns the proper info for the completion
 	// script to handle the directory filtering
@@ -1430,7 +1430,7 @@ func TestValidArgsFuncInBashScript(t *testing.T) {
 	rootCmd.AddCommand(child)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenBashCompletion(buf)
+	assertNoErr(t, rootCmd.GenBashCompletion(buf))
 	output := buf.String()
 
 	check(t, output, "has_completion_function=1")
@@ -1445,7 +1445,7 @@ func TestNoValidArgsFuncInBashScript(t *testing.T) {
 	rootCmd.AddCommand(child)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenBashCompletion(buf)
+	assertNoErr(t, rootCmd.GenBashCompletion(buf))
 	output := buf.String()
 
 	checkOmit(t, output, "has_completion_function=1")
@@ -1461,7 +1461,7 @@ func TestCompleteCmdInBashScript(t *testing.T) {
 	rootCmd.AddCommand(child)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenBashCompletion(buf)
+	assertNoErr(t, rootCmd.GenBashCompletion(buf))
 	output := buf.String()
 
 	check(t, output, ShellCompNoDescRequestCmd)
@@ -1477,7 +1477,7 @@ func TestCompleteNoDesCmdInZshScript(t *testing.T) {
 	rootCmd.AddCommand(child)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenZshCompletionNoDesc(buf)
+	assertNoErr(t, rootCmd.GenZshCompletionNoDesc(buf))
 	output := buf.String()
 
 	check(t, output, ShellCompNoDescRequestCmd)
@@ -1493,7 +1493,7 @@ func TestCompleteCmdInZshScript(t *testing.T) {
 	rootCmd.AddCommand(child)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenZshCompletion(buf)
+	assertNoErr(t, rootCmd.GenZshCompletion(buf))
 	output := buf.String()
 
 	check(t, output, ShellCompRequestCmd)
@@ -1506,7 +1506,7 @@ func TestFlagCompletionInGo(t *testing.T) {
 		Run: emptyRun,
 	}
 	rootCmd.Flags().IntP("introot", "i", -1, "help message for flag introot")
-	rootCmd.RegisterFlagCompletionFunc("introot", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
+	assertNoErr(t, rootCmd.RegisterFlagCompletionFunc("introot", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
 		completions := []string{}
 		for _, comp := range []string{"1\tThe first", "2\tThe second", "10\tThe tenth"} {
 			if strings.HasPrefix(comp, toComplete) {
@@ -1514,9 +1514,9 @@ func TestFlagCompletionInGo(t *testing.T) {
 			}
 		}
 		return completions, ShellCompDirectiveDefault
-	})
+	}))
 	rootCmd.Flags().String("filename", "", "Enter a filename")
-	rootCmd.RegisterFlagCompletionFunc("filename", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
+	assertNoErr(t, rootCmd.RegisterFlagCompletionFunc("filename", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
 		completions := []string{}
 		for _, comp := range []string{"file.yaml\tYAML format", "myfile.json\tJSON format", "file.xml\tXML format"} {
 			if strings.HasPrefix(comp, toComplete) {
@@ -1524,7 +1524,7 @@ func TestFlagCompletionInGo(t *testing.T) {
 			}
 		}
 		return completions, ShellCompDirectiveNoSpace | ShellCompDirectiveNoFileComp
-	})
+	}))
 
 	// Test completing an empty string
 	output, err := executeCommand(rootCmd, ShellCompNoDescRequestCmd, "--introot", "")
@@ -1703,7 +1703,7 @@ func TestFlagCompletionInGoWithDesc(t *testing.T) {
 		Run: emptyRun,
 	}
 	rootCmd.Flags().IntP("introot", "i", -1, "help message for flag introot")
-	rootCmd.RegisterFlagCompletionFunc("introot", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
+	assertNoErr(t, rootCmd.RegisterFlagCompletionFunc("introot", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
 		completions := []string{}
 		for _, comp := range []string{"1\tThe first", "2\tThe second", "10\tThe tenth"} {
 			if strings.HasPrefix(comp, toComplete) {
@@ -1711,9 +1711,9 @@ func TestFlagCompletionInGoWithDesc(t *testing.T) {
 			}
 		}
 		return completions, ShellCompDirectiveDefault
-	})
+	}))
 	rootCmd.Flags().String("filename", "", "Enter a filename")
-	rootCmd.RegisterFlagCompletionFunc("filename", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
+	assertNoErr(t, rootCmd.RegisterFlagCompletionFunc("filename", func(cmd *Command, args []string, toComplete string) ([]string, ShellCompDirective) {
 		completions := []string{}
 		for _, comp := range []string{"file.yaml\tYAML format", "myfile.json\tJSON format", "file.xml\tXML format"} {
 			if strings.HasPrefix(comp, toComplete) {
@@ -1721,7 +1721,7 @@ func TestFlagCompletionInGoWithDesc(t *testing.T) {
 			}
 		}
 		return completions, ShellCompDirectiveNoSpace | ShellCompDirectiveNoFileComp
-	})
+	}))
 
 	// Test completing an empty string
 	output, err := executeCommand(rootCmd, ShellCompRequestCmd, "--introot", "")
diff --git a/doc/man_docs_test.go b/doc/man_docs_test.go
index ee9b87535a..aa3f5f2a18 100644
--- a/doc/man_docs_test.go
+++ b/doc/man_docs_test.go
@@ -13,6 +13,12 @@ import (
 	"github.com/spf13/cobra"
 )
 
+func assertNoErr(t *testing.T, e error) {
+	if e != nil {
+		t.Error(e)
+	}
+}
+
 func translate(in string) string {
 	return strings.Replace(in, "-", "\\-", -1)
 }
@@ -133,7 +139,7 @@ func TestGenManSeeAlso(t *testing.T) {
 func TestManPrintFlagsHidesShortDeperecated(t *testing.T) {
 	c := &cobra.Command{}
 	c.Flags().StringP("foo", "f", "default", "Foo flag")
-	c.Flags().MarkShorthandDeprecated("foo", "don't use it no more")
+	assertNoErr(t, c.Flags().MarkShorthandDeprecated("foo", "don't use it no more"))
 
 	buf := new(bytes.Buffer)
 	manPrintFlags(buf, c.Flags())
diff --git a/doc/man_examples_test.go b/doc/man_examples_test.go
index db6604268a..e20a34c38e 100644
--- a/doc/man_examples_test.go
+++ b/doc/man_examples_test.go
@@ -17,7 +17,7 @@ func ExampleGenManTree() {
 		Title:   "MINE",
 		Section: "3",
 	}
-	doc.GenManTree(cmd, header, "/tmp")
+	cobra.CheckErr(doc.GenManTree(cmd, header, "/tmp"))
 }
 
 func ExampleGenMan() {
@@ -30,6 +30,6 @@ func ExampleGenMan() {
 		Section: "3",
 	}
 	out := new(bytes.Buffer)
-	doc.GenMan(cmd, header, out)
+	cobra.CheckErr(doc.GenMan(cmd, header, out))
 	fmt.Print(out.String())
 }
diff --git a/fish_completions_test.go b/fish_completions_test.go
index 532b6055a7..a3171e481e 100644
--- a/fish_completions_test.go
+++ b/fish_completions_test.go
@@ -15,7 +15,7 @@ func TestCompleteNoDesCmdInFishScript(t *testing.T) {
 	rootCmd.AddCommand(child)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenFishCompletion(buf, false)
+	assertNoErr(t, rootCmd.GenFishCompletion(buf, false))
 	output := buf.String()
 
 	check(t, output, ShellCompNoDescRequestCmd)
@@ -31,7 +31,7 @@ func TestCompleteCmdInFishScript(t *testing.T) {
 	rootCmd.AddCommand(child)
 
 	buf := new(bytes.Buffer)
-	rootCmd.GenFishCompletion(buf, true)
+	assertNoErr(t, rootCmd.GenFishCompletion(buf, true))
 	output := buf.String()
 
 	check(t, output, ShellCompRequestCmd)
@@ -41,7 +41,7 @@ func TestCompleteCmdInFishScript(t *testing.T) {
 func TestProgWithDash(t *testing.T) {
 	rootCmd := &Command{Use: "root-dash", Args: NoArgs, Run: emptyRun}
 	buf := new(bytes.Buffer)
-	rootCmd.GenFishCompletion(buf, false)
+	assertNoErr(t, rootCmd.GenFishCompletion(buf, false))
 	output := buf.String()
 
 	// Functions name should have replace the '-'
@@ -56,7 +56,7 @@ func TestProgWithDash(t *testing.T) {
 func TestProgWithColon(t *testing.T) {
 	rootCmd := &Command{Use: "root:colon", Args: NoArgs, Run: emptyRun}
 	buf := new(bytes.Buffer)
-	rootCmd.GenFishCompletion(buf, false)
+	assertNoErr(t, rootCmd.GenFishCompletion(buf, false))
 	output := buf.String()
 
 	// Functions name should have replace the ':'
diff --git a/powershell_completions_test.go b/powershell_completions_test.go
index 29b609de05..30b354b4b5 100644
--- a/powershell_completions_test.go
+++ b/powershell_completions_test.go
@@ -109,7 +109,7 @@ func TestPowerShellCompletion(t *testing.T) {
 	for _, tc := range tcs {
 		t.Run(tc.name, func(t *testing.T) {
 			buf := new(bytes.Buffer)
-			tc.root.GenPowerShellCompletion(buf)
+			assertNoErr(t, tc.root.GenPowerShellCompletion(buf))
 			output := buf.String()
 
 			for _, expectedExpression := range tc.expectedExpressions {
diff --git a/shell_completions.md b/shell_completions.md
index d8416ab1dc..91ce7724c7 100644
--- a/shell_completions.md
+++ b/shell_completions.md
@@ -91,8 +91,7 @@ cmd := &cobra.Command{
 	Long:    get_long,
 	Example: get_example,
 	Run: func(cmd *cobra.Command, args []string) {
-		err := RunGet(f, out, cmd, args)
-		util.CheckErr(err)
+		cobra.CheckErr(RunGet(f, out, cmd, args))
 	},
 	ValidArgs: validArgs,
 }
@@ -124,7 +123,7 @@ the completion algorithm if entered manually, e.g. in:
 
 ```bash
 $ kubectl get rc [tab][tab]
-backend        frontend       database 
+backend        frontend       database
 ```
 
 Note that without declaring `rc` as an alias, the completion algorithm would not know to show the list of
@@ -246,7 +245,7 @@ and you'll get something like
 
 ```bash
 $ kubectl exec [tab][tab]
--c            --container=  -p            --pod=  
+-c            --container=  -p            --pod=
 ```
 
 ### Specify dynamic flag completion