Added autocompletion for service name (#1547)

* Added autocompletion for service name

* Added unit tests

* Added error handling for panic if no namespace flag added to command

* Removed target field from config

* Modified signature for completion functions

pkg/kn/commands/completion_helper.go

@@ -0,0 +1,125 @@
+// Copyright © 2021 The Knative Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package commands
+
+import (
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+type completionConfig struct {
+	params     *KnParams
+	command    *cobra.Command
+	args       []string
+	toComplete string
+}
+
+var (
+	resourceToFuncMap = map[string]func(config *completionConfig) []string{
+		"service": completeService,
+	}
+)
+
+// ResourceNameCompletionFunc will return a function that will autocomplete the name of
+// the resource based on the subcommand
+func ResourceNameCompletionFunc(p *KnParams) func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+	return func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+
+		var use string
+		if cmd.Parent() != nil {
+			use = cmd.Parent().Use
+		}
+		config := completionConfig{
+			p,
+			cmd,
+			args,
+			toComplete,
+		}
+		return config.getCompletion(use), cobra.ShellCompDirectiveNoFileComp
+	}
+}
+
+func (config *completionConfig) getCompletion(parent string) []string {
+	completionFunc := resourceToFuncMap[parent]
+	if completionFunc == nil {
+		return []string{}
+	}
+	return completionFunc(config)
+}
+
+func getTargetFlagValue(cmd *cobra.Command) string {
+	flag := cmd.Flag("target")
+	if flag == nil {
+		return ""
+	}
+	return flag.Value.String()
+}
+
+func completeGitOps(config *completionConfig) (suggestions []string) {
+	suggestions = make([]string, 0)
+	if len(config.args) != 0 {
+		return
+	}
+	namespace, err := config.params.GetNamespace(config.command)
+	if err != nil {
+		return
+	}
+	client, err := config.params.NewGitopsServingClient(namespace, getTargetFlagValue(config.command))
+	if err != nil {
+		return
+	}
+	serviceList, err := client.ListServices(config.command.Context())
+	if err != nil {
+		return
+	}
+	for _, sug := range serviceList.Items {
+		if !strings.HasPrefix(sug.Name, config.toComplete) {
+			continue
+		}
+		suggestions = append(suggestions, sug.Name)
+	}
+	return
+}
+
+func completeService(config *completionConfig) (suggestions []string) {
+	if getTargetFlagValue(config.command) != "" {
+		return completeGitOps(config)
+	}
+
+	suggestions = make([]string, 0)
+	if len(config.args) != 0 {
+		return
+	}
+	namespace, err := config.params.GetNamespace(config.command)
+	if err != nil {
+		return
+	}
+	client, err := config.params.NewServingClient(namespace)
+	if err != nil {
+		return
+	}
+	serviceList, err := client.ListServices(config.command.Context())
+	if err != nil {
+		return
+	}
+	for _, sug := range serviceList.Items {
+		if !strings.HasPrefix(sug.Name, config.toComplete) {
+			continue
+		}
+		suggestions = append(suggestions, sug.Name)
+	}
+	return
+}

pkg/kn/commands/completion_helper_test.go

@@ -0,0 +1,293 @@
+// Copyright © 2021 The Knative Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package commands
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"gotest.tools/v3/assert"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/cli-runtime/pkg/genericclioptions"
+	clienttesting "k8s.io/client-go/testing"
+	v1 "knative.dev/client/pkg/serving/v1"
+	v12 "knative.dev/serving/pkg/apis/serving/v1"
+	servingv1fake "knative.dev/serving/pkg/client/clientset/versioned/typed/serving/v1/fake"
+)
+
+type testType struct {
+	name       string
+	namespace  string
+	p          *KnParams
+	args       []string
+	toComplete string
+	resource   string
+}
+
+const (
+	testNs  = "test-ns"
+	errorNs = "error-ns"
+)
+
+var (
+	testSvc1 = v12.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "serving.knative.dev/v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{Name: "test-svc-1", Namespace: testNs},
+	}
+	testSvc2 = v12.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "serving.knative.dev/v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{Name: "test-svc-2", Namespace: testNs},
+	}
+	testSvc3 = v12.Service{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "Service",
+			APIVersion: "serving.knative.dev/v1",
+		},
+		ObjectMeta: metav1.ObjectMeta{Name: "test-svc-3", Namespace: testNs},
+	}
+	testNsServices = []v12.Service{testSvc1, testSvc2, testSvc3}
+
+	fakeServing = &servingv1fake.FakeServingV1{Fake: &clienttesting.Fake{}}
+	knParams    = &KnParams{
+		NewServingClient: func(namespace string) (v1.KnServingClient, error) {
+			return v1.NewKnServingClient(fakeServing, namespace), nil
+		},
+		NewGitopsServingClient: func(namespace string, dir string) (v1.KnServingClient, error) {
+			return v1.NewKnServingGitOpsClient(namespace, dir), nil
+		},
+	}
+)
+
+func TestResourceNameCompletionFuncService(t *testing.T) {
+	completionFunc := ResourceNameCompletionFunc(knParams)
+
+	fakeServing.AddReactor("list", "services",
+		func(a clienttesting.Action) (bool, runtime.Object, error) {
+			if a.GetNamespace() == errorNs {
+				return true, nil, errors.NewInternalError(fmt.Errorf("unable to list services"))
+			}
+			return true, &v12.ServiceList{Items: testNsServices}, nil
+		})
+
+	tests := []testType{
+		{
+			"Empty suggestions when no parent command found",
+			testNs,
+			knParams,
+			nil,
+			"",
+			"no-parent",
+		},
+		{
+			"Empty suggestions when non-zero args",
+			testNs,
+			knParams,
+			[]string{"xyz"},
+			"",
+			"service",
+		},
+		{
+			"Empty suggestions when no namespace flag",
+			"",
+			knParams,
+			nil,
+			"",
+			"service",
+		},
+		{
+			"Suggestions when test-ns namespace set",
+			testNs,
+			knParams,
+			nil,
+			"",
+			"service",
+		},
+		{
+			"Empty suggestions when toComplete is not a prefix",
+			testNs,
+			knParams,
+			nil,
+			"xyz",
+			"service",
+		},
+		{
+			"Empty suggestions when error during list operation",
+			errorNs,
+			knParams,
+			nil,
+			"",
+			"service",
+		},
+	}
+	for _, tt := range tests {
+		cmd := getResourceCommandWithTestSubcommand(tt.resource, tt.namespace != "", tt.resource != "no-parent")
+		t.Run(tt.name, func(t *testing.T) {
+			config := &completionConfig{
+				params:     tt.p,
+				command:    cmd,
+				args:       tt.args,
+				toComplete: tt.toComplete,
+			}
+			expectedFunc := resourceToFuncMap[tt.resource]
+			if expectedFunc == nil {
+				expectedFunc = func(config *completionConfig) []string {
+					return []string{}
+				}
+			}
+			cmd.Flags().Set("namespace", tt.namespace)
+			actualSuggestions, actualDirective := completionFunc(cmd, tt.args, tt.toComplete)
+			expectedSuggestions := expectedFunc(config)
+			expectedDirective := cobra.ShellCompDirectiveNoFileComp
+			assert.DeepEqual(t, actualSuggestions, expectedSuggestions)
+			assert.Equal(t, actualDirective, expectedDirective)
+		})
+	}
+}
+
+func TestResourceNameCompletionFuncGitOps(t *testing.T) {
+	tempDir := setupTempDir(t)
+	assert.Assert(t, tempDir != "")
+	defer os.RemoveAll(tempDir)
+
+	completionFunc := ResourceNameCompletionFunc(knParams)
+
+	tests := []testType{
+		{
+			"Empty suggestions when no parent command found",
+			testNs,
+			knParams,
+			nil,
+			"",
+			"service",
+		},
+		{
+			"Empty suggestions when non-zero args",
+			testNs,
+			knParams,
+			[]string{"xyz"},
+			"",
+			"service",
+		},
+		{
+			"Empty suggestions when no namespace flag",
+			"",
+			knParams,
+			nil,
+			"",
+			"service",
+		},
+		{
+			"Suggestions when test-ns namespace set",
+			testNs,
+			knParams,
+			nil,
+			"",
+			"service",
+		},
+		{
+			"Empty suggestions when toComplete is not a prefix",
+			testNs,
+			knParams,
+			nil,
+			"xyz",
+			"service",
+		},
+		{
+			"Empty suggestions when error during list operation",
+			errorNs,
+			knParams,
+			nil,
+			"",
+			"service",
+		},
+	}
+
+	for _, tt := range tests {
+		cmd := getResourceCommandWithTestSubcommand(tt.resource, tt.namespace != "", tt.resource != "no-parent")
+		t.Run(tt.name, func(t *testing.T) {
+			config := &completionConfig{
+				params:     tt.p,
+				command:    cmd,
+				args:       tt.args,
+				toComplete: tt.toComplete,
+			}
+			expectedFunc := resourceToFuncMap[tt.resource]
+			cmd.Flags().String("target", tempDir, "target directory")
+			cmd.Flags().Set("namespace", tt.namespace)
+
+			expectedSuggestions := expectedFunc(config)
+			expectedDirective := cobra.ShellCompDirectiveNoFileComp
+			actualSuggestions, actualDirective := completionFunc(cmd, tt.args, tt.toComplete)
+			assert.DeepEqual(t, actualSuggestions, expectedSuggestions)
+			assert.Equal(t, actualDirective, expectedDirective)
+		})
+	}
+}
+
+func getResourceCommandWithTestSubcommand(resource string, addNamespace, addSubcommand bool) *cobra.Command {
+	testCommand := &cobra.Command{
+		Use: resource,
+	}
+	testSubCommand := &cobra.Command{
+		Use: "test",
+	}
+	if addSubcommand {
+		testCommand.AddCommand(testSubCommand)
+	}
+	if addNamespace {
+		AddNamespaceFlags(testCommand.Flags(), true)
+		AddNamespaceFlags(testSubCommand.Flags(), true)
+	}
+	return testSubCommand
+}
+
+func setupTempDir(t *testing.T) string {
+	tempDir, err := ioutil.TempDir("", "test-dir")
+	assert.NilError(t, err)
+
+	svcPath := path.Join(tempDir, "test-ns", "ksvc")
+	err = os.MkdirAll(svcPath, 0700)
+	assert.NilError(t, err)
+
+	for i, testSvc := range []v12.Service{testSvc1, testSvc2, testSvc3} {
+		tempFile, err := os.Create(path.Join(svcPath, fmt.Sprintf("test-svc-%d.yaml", i+1)))
+		assert.NilError(t, err)
+		writeToFile(t, testSvc, tempFile)
+	}
+
+	return tempDir
+}
+
+func writeToFile(t *testing.T, testSvc v12.Service, tempFile *os.File) {
+	yamlPrinter, err := genericclioptions.NewJSONYamlPrintFlags().ToPrinter("yaml")
+	assert.NilError(t, err)
+
+	err = yamlPrinter.PrintObj(&testSvc, tempFile)
+	assert.NilError(t, err)
+
+	defer tempFile.Close()
+}

pkg/kn/commands/namespaced.go

@@ -15,6 +15,8 @@
 package commands
 
 import (
+	"fmt"
+
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"k8s.io/client-go/tools/clientcmd"
@@ -43,7 +45,11 @@ func AddNamespaceFlags(flags *pflag.FlagSet, allowAll bool) {
 
 // GetNamespace returns namespace from command specified by flag
 func (params *KnParams) GetNamespace(cmd *cobra.Command) (string, error) {
-	namespace := cmd.Flag("namespace").Value.String()
+	namespaceFlag := cmd.Flag("namespace")
+	if namespaceFlag == nil {
+		return "", fmt.Errorf("command %s doesn't have --namespace flag", cmd.Name())
+	}
+	namespace := namespaceFlag.Value.String()
 	// check value of all-namespaces only if its defined
 	if cmd.Flags().Lookup("all-namespaces") != nil {
 		all, err := cmd.Flags().GetBool("all-namespaces")

pkg/kn/commands/service/delete.go

@@ -102,6 +102,7 @@ func NewServiceDeleteCommand(p *commands.KnParams) *cobra.Command {
 			}
 			return nil
 		},
+		ValidArgsFunction: commands.ResourceNameCompletionFunc(p),
 	}
 	flags := serviceDeleteCommand.Flags()
 	flags.Bool("all", false, "Delete all services in a namespace.")

pkg/kn/commands/service/describe.go

@@ -97,6 +97,7 @@ func NewServiceDescribeCommand(p *commands.KnParams) *cobra.Command {
 		Use:               "describe NAME",
 		Short:             "Show details of a service",
 		Example:           describe_example,
+		ValidArgsFunction: commands.ResourceNameCompletionFunc(p),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			if len(args) != 1 {
 				return errors.New("'service describe' requires the service name given as single argument")

pkg/kn/commands/service/update.go

@@ -68,6 +68,7 @@ func NewServiceUpdateCommand(p *commands.KnParams) *cobra.Command {
 		Use:               "update NAME",
 		Short:             "Update a service",
 		Example:           updateExample,
+		ValidArgsFunction: commands.ResourceNameCompletionFunc(p),
 		RunE: func(cmd *cobra.Command, args []string) (err error) {
 			if len(args) != 1 {
 				return errors.New("'service update' requires the service name given as single argument")