fix lint errors (knative#388)

* fix typo (misspell)

* ineffectual assignment to err (ineffassign)

* if block ends with a return statement, so drop this else and outdent its block (golint)

* should replace errors.New(fmt.Sprintf(...)) with fmt.Errorf(...) (golint)

* struct field LogHttp should be LogHTTP (golint)

* fix last typo

pkg/kn/commands/namespaced_test.go

@@ -63,7 +63,7 @@ func TestGetNamespaceDefault(t *testing.T) {
 }
 
 // test with all-namespaces flag set with sample namespace
-// all-namespaces flag takes the precendence
+// all-namespaces flag takes the precedence
 func TestGetNamespaceAllNamespacesSet(t *testing.T) {
 	testCmd := testCommandGenerator(true)
 	expectedNamespace := ""
@@ -86,7 +86,7 @@ func TestGetNamespaceAllNamespacesSet(t *testing.T) {
 }
 
 // test with all-namespace flag set without any namespace flag set
-// all-namespace flag takes precendence
+// all-namespace flag takes precedence
 func TestGetNamespaceDefaultAllNamespacesUnset(t *testing.T) {
 	testCmd := testCommandGenerator(true)
 	expectedNamespace := ""

pkg/kn/commands/plugin/plugin_handler_test.go

@@ -137,7 +137,7 @@ func TestPluginHandler(t *testing.T) {
 	})
 
 	t.Run("HandlePluginCommand", func(t *testing.T) {
-		t.Run("sucess handling", func(t *testing.T) {
+		t.Run("success handling", func(t *testing.T) {
 			setup(t)
 			defer cleanup(t)
 			beforeEach(t)

pkg/kn/commands/plugin/plugin_list_test.go

@@ -212,6 +212,7 @@ func TestPluginList(t *testing.T) {
 			defer ctx.cleanup()
 
 			err := ctx.createTestPlugin(KnTestPluginName, FileModeExecutable, false)
+			assert.NilError(t, err)
 
 			err = ctx.execute("plugin", "list")
 			assert.NilError(t, err)

pkg/kn/commands/plugin/plugin_verifier.go

@@ -33,7 +33,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// pluginVerifier verifies that existing kn commands are not overriden
+// pluginVerifier verifies that existing kn commands are not overridden
 type pluginVerifier struct {
 	root        *cobra.Command
 	seenPlugins map[string]string

pkg/kn/commands/plugin/plugin_verifier_windows.go

@@ -29,7 +29,7 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// pluginVerifier verifies that existing kn commands are not overriden
+// pluginVerifier verifies that existing kn commands are not overridden
 type pluginVerifier struct {
 	root        *cobra.Command
 	seenPlugins map[string]string

pkg/kn/commands/service/service_create_test.go

@@ -173,6 +173,9 @@ func TestServiceCreateEnv(t *testing.T) {
 	}
 
 	template, err := servinglib.RevisionTemplateOfService(created)
+	if err != nil {
+		t.Fatal(err)
+	}
 	actualEnvVars, err := servinglib.EnvToMap(template.Spec.Containers[0].Env)
 	if err != nil {
 		t.Fatal(err)
@@ -453,10 +456,10 @@ func TestServiceCreateEnvForce(t *testing.T) {
 		"B": "LIONS"}
 
 	template, err := servinglib.RevisionTemplateOfService(created)
-	actualEnvVars, err := servinglib.EnvToMap(template.Spec.Containers[0].Env)
 	if err != nil {
 		t.Fatal(err)
 	}
+	actualEnvVars, err := servinglib.EnvToMap(template.Spec.Containers[0].Env)
 	if err != nil {
 		t.Fatal(err)
 	} else if template.Spec.Containers[0].Image != "gcr.io/foo/bar:v2" {

pkg/kn/commands/service/service_describe.go

@@ -145,6 +145,9 @@ func NewServiceDescribeCommand(p *commands.KnParams) *cobra.Command {
 			}
 
 			revisionDescs, err := getRevisionDescriptions(client, service, printDetails)
+			if err != nil {
+				return err
+			}
 
 			return describe(cmd.OutOrStdout(), service, revisionDescs)
 		},

pkg/kn/commands/service/service_update.go

@@ -127,7 +127,7 @@ func NewServiceUpdateCommand(p *commands.KnParams) *cobra.Command {
 
 func preCheck(cmd *cobra.Command, args []string) error {
 	if cmd.Flags().NFlag() == 0 {
-		return errors.New(fmt.Sprintf("flag(s) not set\nUsage: %s", cmd.Use))
+		return fmt.Errorf("flag(s) not set\nUsage: %s", cmd.Use)
 	}
 
 	return nil

pkg/kn/commands/types.go

@@ -15,7 +15,6 @@
 package commands
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -47,7 +46,7 @@ type KnParams struct {
 	NewClient    func(namespace string) (serving_kn_v1alpha1.KnClient, error)
 
 	// General global options
-	LogHttp bool
+	LogHTTP bool
 
 	// Set this if you want to nail down the namespace
 	fixedCurrentNamespace string
@@ -82,7 +81,7 @@ func (params *KnParams) GetConfig() (serving_v1alpha1_client.ServingV1alpha1Inte
 	if err != nil {
 		return nil, err
 	}
-	if params.LogHttp {
+	if params.LogHTTP {
 		// TODO: When we update to the newer version of client-go, replace with
 		// config.Wrap() for future compat.
 		config.WrapTransport = util.NewLoggingTransport
@@ -110,9 +109,8 @@ func (params *KnParams) GetClientConfig() (clientcmd.ClientConfig, error) {
 
 	paths := filepath.SplitList(params.KubeCfgPath)
 	if len(paths) > 1 {
-		return nil, errors.New(fmt.Sprintf("Can not find config file. '%s' looks like a path. "+
-			"Please use the env var KUBECONFIG if you want to check for multiple configuration files", params.KubeCfgPath))
-	} else {
-		return nil, errors.New(fmt.Sprintf("Config file '%s' can not be found", params.KubeCfgPath))
+		return nil, fmt.Errorf("Can not find config file. '%s' looks like a path. "+
+			"Please use the env var KUBECONFIG if you want to check for multiple configuration files", params.KubeCfgPath)
 	}
+	return nil, fmt.Errorf("Config file '%s' can not be found", params.KubeCfgPath)
 }

pkg/kn/commands/types_test.go

@@ -77,7 +77,7 @@ func TestGetConfig(t *testing.T) {
 	} {
 		p := &KnParams{
 			ClientConfig: tc.clientConfig,
-			LogHttp:      tc.logHttp,
+			LogHTTP:      tc.logHttp,
 		}
 
 		_, err := p.GetConfig()

pkg/kn/core/root.go

@@ -15,7 +15,6 @@
 package core
 
 import (
-	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -130,7 +129,7 @@ func NewKnCommand(params ...commands.KnParams) *cobra.Command {
 	// Persistent flags
 	rootCmd.PersistentFlags().StringVar(&commands.CfgFile, "config", "", "kn config file (default is $HOME/.kn/config.yaml)")
 	rootCmd.PersistentFlags().StringVar(&p.KubeCfgPath, "kubeconfig", "", "kubectl config file (default is $HOME/.kube/config)")
-	flags.AddBothBoolFlags(rootCmd.PersistentFlags(), &p.LogHttp, "log-http", "", false, "log http traffic")
+	flags.AddBothBoolFlags(rootCmd.PersistentFlags(), &p.LogHTTP, "log-http", "", false, "log http traffic")
 
 	plugin.AddPluginFlags(rootCmd)
 	plugin.BindPluginsFlagToViper(rootCmd)
@@ -175,10 +174,9 @@ func EmptyAndUnknownSubCommands(cmd *cobra.Command) {
 				fmt.Println()
 
 				if len(args) == 0 {
-					return errors.New(fmt.Sprintf("please provide a valid sub-command for \"kn %s\"", aCmd.Name()))
-				} else {
-					return errors.New(fmt.Sprintf("unknown sub-command \"%s\" for \"kn %s\"", args[0], aCmd.Name()))
+					return fmt.Errorf("please provide a valid sub-command for \"kn %s\"", aCmd.Name())
 				}
+				return fmt.Errorf("unknown sub-command \"%s\" for \"kn %s\"", args[0], aCmd.Name())
 			}
 		}
 

pkg/kn/traffic/compute.go

@@ -240,9 +240,8 @@ func verifyInputSanity(trafficFlags *flags.Traffic) error {
 		// To check if there are duplicate revision names in traffic flags
 		if _, exist := revisionRefMap[revisionRef]; exist {
 			return errorRepeatingRevision("--traffic", revisionRef)
-		} else {
-			revisionRefMap[revisionRef] = i
 		}
+		revisionRefMap[revisionRef] = i
 
 		percentInt, err := strconv.Atoi(percent)
 		if err != nil {

pkg/serving/schema_handling.go

@@ -15,7 +15,6 @@
 package serving
 
 import (
-	"errors"
 	"fmt"
 
 	"k8s.io/apimachinery/pkg/runtime"
@@ -44,5 +43,5 @@ func GetGroupVersionKind(obj runtime.Object, gv schema.GroupVersion) (*schema.Gr
 			return &gvk, nil
 		}
 	}
-	return nil, errors.New(fmt.Sprintf("no group version %s registered in %s", gv, scheme.Scheme.Name()))
+	return nil, fmt.Errorf("no group version %s registered in %s", gv, scheme.Scheme.Name())
 }

pkg/util/parsing_helper.go

@@ -37,9 +37,8 @@ func mapFromArray(arr []string, delimiter string, allowSingles bool) (map[string
 		if len(pairSlice) <= 1 {
 			if len(pairSlice) == 0 || !allowSingles {
 				return nil, fmt.Errorf("Argument requires a value that contains the %q character; got %q", delimiter, pairStr)
-			} else {
-				returnMap[pairSlice[0]] = ""
 			}
+			returnMap[pairSlice[0]] = ""
 		} else {
 			returnMap[pairSlice[0]] = pairSlice[1]
 		}

test/e2e/common.go

@@ -57,7 +57,7 @@ func NewE2eTest(t *testing.T) *e2eTest {
 	}
 }
 
-// Setup set up an enviroment for kn integration test returns the Teardown cleanup function
+// Setup set up an environment for kn integration test returns the Teardown cleanup function
 func (test *e2eTest) Setup(t *testing.T) {
 	test.env.Namespace = fmt.Sprintf("%s%d", test.env.Namespace, getNamespaceCountAndIncrement())
 	test.kn = kn{t, test.env.Namespace, Logger{}}

test/e2e/service_test.go

@@ -47,6 +47,7 @@ func TestService(t *testing.T) {
 
 func (test *e2eTest) serviceCreateDuplicate(t *testing.T, serviceName string) {
 	out, err := test.kn.RunWithOpts([]string{"service", "list", serviceName}, runOpts{NoNamespace: false})
+	assert.NilError(t, err)
 	assert.Check(t, strings.Contains(out, serviceName), "The service does not exist yet")
 
 	_, err = test.kn.RunWithOpts([]string{"service", "create", serviceName,
@@ -65,6 +66,7 @@ func (test *e2eTest) serviceDescribeWithPrintFlags(t *testing.T, serviceName str
 
 func (test *e2eTest) serviceDeleteNonexistent(t *testing.T, serviceName string) {
 	out, err := test.kn.RunWithOpts([]string{"service", "list", serviceName}, runOpts{NoNamespace: false})
+	assert.NilError(t, err)
 	assert.Check(t, !strings.Contains(out, serviceName), "The service exists")
 
 	_, err = test.kn.RunWithOpts([]string{"service", "delete", serviceName}, runOpts{NoNamespace: false, AllowError: true})

test/e2e/traffic_split_test.go

@@ -223,7 +223,7 @@ func TestTrafficSplit(t *testing.T) {
 		},
 	)
 	// test reducing number of targets from traffic blockdd
-	t.Run("remove a revision with tag old from traffic block entierly",
+	t.Run("remove a revision with tag old from traffic block entirely",
 		func(t *testing.T) {
 			serviceName := getServiceNameAndIncrement(serviceBase)
 			test.serviceCreate(t, serviceName)