How to use installError method of install Package

1/* Copyright 2020 Google Inc.2Licensed under the Apache License, Version 2.0 (the "License");3you may not use this file except in compliance with the License.4You may obtain a copy of the License at5    https://www.apache.org/licenses/LICENSE-2.06Unless required by applicable law or agreed to in writing, software7distributed under the License is distributed on an "AS IS" BASIS,8WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.9See the License for the specific language governing permissions and10limitations under the License.11*/12package os13import (14	"bytes"15	"context"16	"crypto/rand"17	"errors"18	"fmt"19	"io"20	"reflect"21	"testing"22	"time"23	"github.com/google/gnxi/gnoi/os/pb"24	"google.golang.org/grpc"25)26const readChunkSize = 4000000 // 4MB. Highest amount of data a chunk should be since >5MB will cause a grpc transport error.27type activateRPC func(ctx context.Context, in *pb.ActivateRequest, opts ...grpc.CallOption) (*pb.ActivateResponse, error)28type verifyRPC func(ctx context.Context, in *pb.VerifyRequest, opts ...grpc.CallOption) (*pb.VerifyResponse, error)29type mockClient struct {30	pb.OSClient31	activate      activateRPC32	verify        verifyRPC33	installClient pb.OS_InstallClient34}35type installRequestMap struct {36	req  *pb.InstallRequest37	resp *pb.InstallResponse38}39type mockInstallClient struct {40	pb.OS_InstallClient41	reqMap  []*installRequestMap42	i       int43	recv    chan int44	recvErr chan *pb.InstallResponse_InstallError45}46func (c *mockInstallClient) Send(req *pb.InstallRequest) error {47	if c.i < len(c.reqMap) {48		if reflect.TypeOf(req.Request) == reflect.TypeOf(c.reqMap[c.i].req.Request) {49			c.recv <- c.i50		} else {51			c.recvErr <- &pb.InstallResponse_InstallError{52				InstallError: &pb.InstallError{Type: pb.InstallError_UNSPECIFIED, Detail: "Invalid command"},53			}54		}55		c.i++56	}57	return nil58}59func (c *mockInstallClient) Recv() (*pb.InstallResponse, error) {60	select {61	case i := <-c.recv:62		res := c.reqMap[i].resp63		if res == nil {64			<-time.After(200 * time.Millisecond)65			return &pb.InstallResponse{66				Response: &pb.InstallResponse_InstallError{67					InstallError: &pb.InstallError{Type: pb.InstallError_UNSPECIFIED, Detail: "Invalid command"},68				},69			}, nil70		}71		return res, nil72	case err := <-c.recvErr:73		return &pb.InstallResponse{Response: err}, nil74	}75}76func (c *mockInstallClient) CloseSend() error {77	return nil78}79func (c *mockClient) Activate(ctx context.Context, in *pb.ActivateRequest, opts ...grpc.CallOption) (*pb.ActivateResponse, error) {80	return c.activate(ctx, in, opts...)81}82func (c *mockClient) Verify(ctx context.Context, in *pb.VerifyRequest, opts ...grpc.CallOption) (*pb.VerifyResponse, error) {83	return c.verify(ctx, in, opts...)84}85func (c *mockClient) Install(ctx context.Context, opts ...grpc.CallOption) (pb.OS_InstallClient, error) {86	return c.installClient, nil87}88func activateErrorRPC(errType pb.ActivateError_Type, detail string) activateRPC {89	return func(ctx context.Context, in *pb.ActivateRequest, opts ...grpc.CallOption) (*pb.ActivateResponse, error) {90		return &pb.ActivateResponse{91			Response: &pb.ActivateResponse_ActivateError{92				ActivateError: &pb.ActivateError{Type: errType, Detail: detail},93			}}, nil94	}95}96func activateSuccessRPC(ctx context.Context, in *pb.ActivateRequest, opts ...grpc.CallOption) (*pb.ActivateResponse, error) {97	return &pb.ActivateResponse{98		Response: &pb.ActivateResponse_ActivateOk{}}, nil99}100func readBytes(num int) func(string) (io.ReaderAt, uint64, func() error, error) {101	b := make([]byte, num)102	rand.Read(b)103	return func(_ string) (io.ReaderAt, uint64, func() error, error) {104		return bytes.NewReader(b), uint64(num), func() error { return nil }, nil105	}106}107func TestInstall(t *testing.T) {108	installTests := []struct {109		name    string110		reqMap  []*installRequestMap111		reader  func(string) (io.ReaderAt, uint64, func() error, error)112		err     error113		timeout time.Duration114	}{115		{116			"Already validated",117			[]*installRequestMap{118				{119					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},120					&pb.InstallResponse{Response: &pb.InstallResponse_Validated{Validated: &pb.Validated{}}},121				},122			},123			readBytes(0),124			nil,125			100 * time.Millisecond,126		},127		{128			"File size of one chunk then validated",129			[]*installRequestMap{130				{131					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},132					&pb.InstallResponse{Response: &pb.InstallResponse_TransferReady{}},133				},134				{135					&pb.InstallRequest{Request: &pb.InstallRequest_TransferContent{}},136					&pb.InstallResponse{Response: &pb.InstallResponse_TransferProgress{TransferProgress: &pb.TransferProgress{BytesReceived: readChunkSize}}},137				},138				{139					&pb.InstallRequest{Request: &pb.InstallRequest_TransferEnd{}},140					&pb.InstallResponse{Response: &pb.InstallResponse_Validated{Validated: &pb.Validated{}}},141				},142			},143			readBytes(int(readChunkSize)),144			nil,145			100 * time.Millisecond,146		},147		{148			"File size of two chunks + 1 then validated",149			[]*installRequestMap{150				{151					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},152					&pb.InstallResponse{Response: &pb.InstallResponse_TransferReady{}},153				},154				{155					&pb.InstallRequest{Request: &pb.InstallRequest_TransferContent{}},156					&pb.InstallResponse{Response: &pb.InstallResponse_TransferProgress{TransferProgress: &pb.TransferProgress{BytesReceived: readChunkSize}}},157				},158				{159					&pb.InstallRequest{Request: &pb.InstallRequest_TransferContent{}},160					&pb.InstallResponse{Response: &pb.InstallResponse_TransferProgress{TransferProgress: &pb.TransferProgress{BytesReceived: (readChunkSize * 2)}}},161				},162				{163					&pb.InstallRequest{Request: &pb.InstallRequest_TransferContent{}},164					&pb.InstallResponse{Response: &pb.InstallResponse_TransferProgress{TransferProgress: &pb.TransferProgress{BytesReceived: (readChunkSize * 2) + 1}}},165				},166				{167					&pb.InstallRequest{Request: &pb.InstallRequest_TransferEnd{}},168					&pb.InstallResponse{Response: &pb.InstallResponse_Validated{Validated: &pb.Validated{}}},169				},170			},171			readBytes((int(readChunkSize) * 2) + 1),172			nil,173			100 * time.Millisecond,174		},175		{176			"File size of one chunk but INCOMPATIBLE InstallError",177			[]*installRequestMap{178				{179					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},180					&pb.InstallResponse{Response: &pb.InstallResponse_TransferReady{}},181				},182				{183					&pb.InstallRequest{Request: &pb.InstallRequest_TransferContent{}},184					&pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_INCOMPATIBLE}}},185				},186			},187			readBytes(int(readChunkSize)),188			errors.New("InstallError occurred: INCOMPATIBLE"),189			100 * time.Millisecond,190		},191		{192			"TransferRequest but INCOMPATIBLE InstallError",193			[]*installRequestMap{194				{195					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},196					&pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_INCOMPATIBLE}}},197				},198			},199			readBytes(0),200			errors.New("InstallError occurred: INCOMPATIBLE"),201			100 * time.Millisecond,202		},203		{204			"TransferRequest but Unspecified InstallError",205			[]*installRequestMap{206				{207					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},208					&pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_UNSPECIFIED, Detail: "Unspecified"}}},209				},210			},211			readBytes(0),212			errors.New("Unspecified InstallError error: Unspecified"),213			100 * time.Millisecond,214		},215		{216			"File size of two chunks but Unspecified InstallError",217			[]*installRequestMap{218				{219					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},220					&pb.InstallResponse{Response: &pb.InstallResponse_TransferReady{}},221				},222				{223					&pb.InstallRequest{Request: &pb.InstallRequest_TransferContent{}},224					&pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_UNSPECIFIED, Detail: "Unspecified"}}},225				},226			},227			readBytes(int(readChunkSize) * 2),228			errors.New("Unspecified InstallError error: Unspecified"),229			100 * time.Millisecond,230		},231		{232			"File size of one chunk then timout",233			[]*installRequestMap{234				{235					&pb.InstallRequest{Request: &pb.InstallRequest_TransferRequest{TransferRequest: &pb.TransferRequest{Version: "version"}}},236					&pb.InstallResponse{Response: &pb.InstallResponse_TransferReady{}},237				},238				{239					&pb.InstallRequest{Request: &pb.InstallRequest_TransferContent{}},240					&pb.InstallResponse{Response: &pb.InstallResponse_TransferProgress{TransferProgress: &pb.TransferProgress{BytesReceived: readChunkSize}}},241				},242				{243					&pb.InstallRequest{Request: &pb.InstallRequest_TransferEnd{}},244					nil,245				},246			},247			readBytes(int(readChunkSize)),248			errors.New("Validation timed out"),249			50 * time.Millisecond,250		},251	}252	for _, test := range installTests {253		t.Run(test.name, func(t *testing.T) {254			client := Client{255				client: &mockClient{installClient: &mockInstallClient{256					reqMap:  test.reqMap,257					recv:    make(chan int, 1),258					recvErr: make(chan *pb.InstallResponse_InstallError, 1),259				}},260			}261			fileReader = test.reader262			if err := client.Install(context.Background(), "", "version", test.timeout, readChunkSize); fmt.Sprintf("%v", err) != fmt.Sprintf("%v", test.err) {263				t.Errorf("Wanted error: **%v** but got error: **%v**", test.err, err)264			}265		})266	}267}268func TestActivate(t *testing.T) {269	activateTests := []struct {270		name    string271		client  *mockClient272		wantErr bool273	}{274		{275			"Success",276			&mockClient{activate: activateSuccessRPC},277			false,278		},279		{280			"Unspecified",281			&mockClient{activate: activateErrorRPC(pb.ActivateError_UNSPECIFIED, "detail")},282			true,283		},284		{285			"Non Existent Version",286			&mockClient{activate: activateErrorRPC(pb.ActivateError_NON_EXISTENT_VERSION, "")},287			true,288		},289	}290	for _, test := range activateTests {291		t.Run(test.name, func(t *testing.T) {292			client := Client{client: test.client}293			got := client.Activate(context.Background(), "version")294			if test.wantErr {295				if got == nil {296					t.Error("want error, got nil")297				}298			} else if got != nil {299				t.Errorf("want <nil>, got: %v", got)300			}301		})302	}303}304func TestVerify(t *testing.T) {305	verifyTests := []struct {306		name,307		runningVersion,308		failMessage string309	}{310		{"Is Running", "version", ""},311		{"Previous Activation Fail", "version", "Activation fail"},312	}313	for _, test := range verifyTests {314		t.Run(test.name, func(t *testing.T) {315			client := Client{client: &mockClient{316				verify: func(ctx context.Context, in *pb.VerifyRequest, opts ...grpc.CallOption) (*pb.VerifyResponse, error) {317					return &pb.VerifyResponse{Version: test.runningVersion, ActivationFailMessage: test.failMessage}, nil318				},319			}}320			version, activationErr, err := client.Verify(context.Background())321			if err != nil {322				t.Errorf("Verify RPC error: %w", err)323			}324			if activationErr != test.failMessage || version != test.runningVersion {325				t.Errorf(326					"Expected VerifyResponse(%s, %s) but got VerifyResponse(%s, %s)",327					test.runningVersion,328					test.failMessage,329					version,330					activationErr,331				)332			}333		})334	}335}...

1/* Copyright 2020 Google Inc.2Licensed under the Apache License, Version 2.0 (the "License");3you may not use this file except in compliance with the License.4You may obtain a copy of the License at5    https://www.apache.org/licenses/LICENSE-2.06Unless required by applicable law or agreed to in writing, software7distributed under the License is distributed on an "AS IS" BASIS,8WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.9See the License for the specific language governing permissions and10limitations under the License.11*/12package os13import (14	"bytes"15	"context"16	"errors"17	log "github.com/golang/glog"18	"github.com/golang/protobuf/proto"19	"github.com/google/gnxi/gnoi/os/pb"20	"github.com/google/gnxi/utils/mockos"21	"google.golang.org/grpc"22)23var receiveChunkSizeAck uint64 = 1200000024// Server is an OS Management service.25type Server struct {26	pb.OSServer27	manager      *Manager28	installToken chan bool29}30// NewServer returns an OS Management service.31func NewServer(settings *Settings) *Server {32	if settings.ReceiveChunkSizeAck != 0 {33		receiveChunkSizeAck = settings.ReceiveChunkSizeAck34	}35	server := &Server{36		manager:      NewManager(settings.FactoryVersion),37		installToken: make(chan bool, 1),38	}39	for _, version := range settings.InstalledVersions {40		server.manager.Install(version, "")41	}42	server.manager.SetRunning(settings.FactoryVersion)43	server.installToken <- true44	return server45}46// Register registers the server into the the gRPC server provided.47func (s *Server) Register(g *grpc.Server) {48	pb.RegisterOSServer(g, s)49}50// Activate sets the requested OS version as the version which is used at the next reboot, and reboots the Target.51func (s *Server) Activate(ctx context.Context, request *pb.ActivateRequest) (*pb.ActivateResponse, error) {52	if err := s.manager.SetRunning(request.Version); err != nil {53		return &pb.ActivateResponse{54			Response: &pb.ActivateResponse_ActivateError{55				ActivateError: &pb.ActivateError{56					Type: pb.ActivateError_NON_EXISTENT_VERSION,57				},58			}}, nil59	}60	return &pb.ActivateResponse{Response: &pb.ActivateResponse_ActivateOk{}}, nil61}62// Verify returns the OS version currently running.63func (s *Server) Verify(ctx context.Context, _ *pb.VerifyRequest) (*pb.VerifyResponse, error) {64	return &pb.VerifyResponse{65		Version:               s.manager.runningVersion,66		ActivationFailMessage: s.manager.activationFailMessage,67	}, nil68}69// Install receives an OS package, validates the package and then installs the package.70func (s *Server) Install(stream pb.OS_InstallServer) error {71	var request *pb.InstallRequest72	var response *pb.InstallResponse73	var err error74	if request, err = stream.Recv(); err != nil {75		return err76	}77	log.V(1).Info("InstallRequest:\n", proto.MarshalTextString(request))78	transferRequest := request.GetTransferRequest()79	if transferRequest == nil {80		return errors.New("Failed to receive TransferRequest")81	}82	if version := transferRequest.Version; s.manager.IsInstalled(version) {83		response = &pb.InstallResponse{Response: &pb.InstallResponse_Validated{84			Validated: &pb.Validated{85				Version: version,86			},87		}}88		log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))89		if err = stream.Send(response); err != nil {90			return err91		}92		return nil93	}94	select {95	case <-s.installToken:96		defer func() {97			s.installToken <- true98		}()99	default:100		response = &pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_INSTALL_IN_PROGRESS}}}101		log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))102		if err = stream.Send(response); err != nil {103			return err104		}105		return errors.New("Another install is already in progress")106	}107	response = &pb.InstallResponse{Response: &pb.InstallResponse_TransferReady{TransferReady: &pb.TransferReady{}}}108	log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))109	if err = stream.Send(response); err != nil {110		return err111	}112	bb, err := ReceiveOS(stream)113	if err != nil {114		return err115	}116	mockOS := mockos.ValidateOS(bb)117	if mockOS == nil {118		response = &pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_PARSE_FAIL}}}119		log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))120		if err = stream.Send(response); err != nil {121			return err122		}123		return nil124	}125	if !mockOS.CheckHash() {126		response := &pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_INTEGRITY_FAIL}}}127		log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))128		if err = stream.Send(response); err != nil {129			return err130		}131		return nil132	}133	if mockOS.Incompatible {134		response := &pb.InstallResponse{Response: &pb.InstallResponse_InstallError{InstallError: &pb.InstallError{Type: pb.InstallError_INCOMPATIBLE, Detail: "Unsupported OS Version"}}}135		log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))136		if err = stream.Send(response); err != nil {137			return err138		}139		return nil140	}141	if s.manager.IsRunning(mockOS.Version) {142		response = &pb.InstallResponse{Response: &pb.InstallResponse_InstallError{143			InstallError: &pb.InstallError{Type: pb.InstallError_INSTALL_RUN_PACKAGE},144		}}145		log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))146		if err = stream.Send(response); err != nil {147			return err148		}149		return nil150	}151	s.manager.Install(mockOS.Version, mockOS.ActivationFailMessage)152	response = &pb.InstallResponse{Response: &pb.InstallResponse_Validated{Validated: &pb.Validated{Version: mockOS.Version}}}153	log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))154	if err = stream.Send(response); err != nil {155		return err156	}157	return nil158}159// ReceiveOS receives and parses requests from stream, storing OS package into a buffer, and updating the progress.160func ReceiveOS(stream pb.OS_InstallServer) (*bytes.Buffer, error) {161	bb := &bytes.Buffer{}162	prev := 0163	for {164		in, err := stream.Recv()165		if err != nil {166			return nil, err167		}168		switch in.Request.(type) {169		case *pb.InstallRequest_TransferContent:170			bb.Write(in.GetTransferContent())171		case *pb.InstallRequest_TransferEnd:172			log.V(1).Info("InstallRequest:\n", proto.MarshalTextString(in))173			return bb, nil174		default:175			log.V(1).Info("InstallRequest:\n", proto.MarshalTextString(in))176			return nil, errors.New("Unknown request type")177		}178		if curr := bb.Len() / int(receiveChunkSizeAck); curr > prev {179			prev = curr180			response := &pb.InstallResponse{Response: &pb.InstallResponse_TransferProgress{181				TransferProgress: &pb.TransferProgress{BytesReceived: uint64(bb.Len())},182			}}183			log.V(1).Info("InstallResponse:\n", proto.MarshalTextString(response))184			if err = stream.Send(response); err != nil {185				return nil, err186			}187		}188	}189}...

...32}33func TestReInstallContinuesIfUninstallFails(t *testing.T) {34	ctrl := gomock.NewController(t)35	defer ctrl.Finish()36	uninstallError := errors.New("uninstall failed")37	adbMock := mock_adb.NewMockAdb(ctrl)38	adbMock.EXPECT().Uninstall(gomock.Any(), gomock.Any()).Return(executionResultError(uninstallError))39	adbMock.EXPECT().Install(gomock.Any(), gomock.Any()).Return(executionResultOk())40	installer := installerImpl{41		adb: adbMock,42	}43	err := installer.Reinstall(apks.Apk{}, devices.Device{})44	if err != nil {45		t.Error(fmt.Sprintf("Expected to ignore uninstall error but got '%v'", err))46	}47}48func TestReInstallFailsIfInstallFails(t *testing.T) {49	installError := errors.New("install failed")50	ctrl := gomock.NewController(t)51	defer ctrl.Finish()52	adbMock := mock_adb.NewMockAdb(ctrl)53	adbMock.EXPECT().Uninstall(gomock.Any(), gomock.Any()).Return(executionResultOk())54	adbMock.EXPECT().Install(gomock.Any(), gomock.Any()).Return(executionResultError(installError))55	installer := installerImpl{56		adb: adbMock,57	}58	err := installer.Reinstall(apks.Apk{}, devices.Device{})59	if err != installError {60		t.Error(fmt.Sprintf("Install error '%v' expected but got '%v", installError, err))61	}62}63func executionResultOk() command.ExecutionResult {64	return command.ExecutionResult{Error: nil}65}66func executionResultError(err error) command.ExecutionResult {67	return command.ExecutionResult{Error: err}68}...

1func main() {2    install := install.Install{}3    install.InstallError()4}5func main() {6    install := install.Install{}7    install.InstallError()8}9func main() {10    install := install.Install{}11    install.InstallError()12}13func main() {14    install := install.Install{}15    install.InstallError()16}17func main() {18    install := install.Install{}19    install.InstallError()20}21func main() {22    install := install.Install{}23    install.InstallError()24}25func main() {26    install := install.Install{}27    install.InstallError()28}29func main() {30    install := install.Install{}31    install.InstallError()32}33func main() {34    install := install.Install{}35    install.InstallError()36}37func main() {38    install := install.Install{}39    install.InstallError()40}41func main() {42    install := install.Install{}43    install.InstallError()44}45func main() {46    install := install.Install{}47    install.InstallError()48}49func main() {50    install := install.Install{}51    install.InstallError()52}53func main() {54    install := install.Install{}55    install.InstallError()56}

1import "fmt"2func main() {3    install := new(Install)4    install.installError()5}6import "fmt"7func main() {8    install := new(Install)9    install.installError()10}11import "fmt"12func main() {13    install := new(Install)14    install.installError()15}16import "fmt"17func main() {18    install := new(Install)19    install.installError()20}21import "fmt"22func main() {23    install := new(Install)24    install.installError()25}26import "fmt"27func main() {28    install := new(Install)29    install.installError()30}31import "fmt"32func main() {33    install := new(Install)34    install.installError()35}36import "fmt"37func main() {38    install := new(Install)39    install.installError()40}41import "fmt"42func main() {43    install := new(Install)44    install.installError()45}46import "fmt"47func main() {48    install := new(Install)49    install.installError()50}51import "fmt"52func main() {53    install := new(Install)54    install.installError()55}56import "fmt"57func main() {58    install := new(Install)59    install.installError()60}

1import (2type install interface {3	installError() string4}5type installClass struct {6}7func (i *installClass) installError() string {8}9func main() {10	i := &installClass{err: "error"}11	fmt.Println(i.installError())12}13import (14type install interface {15	installError() string16}17type installClass struct {18}19func (i *installClass) installError() string {20}21func main() {22	i := &installClass{err: "error"}23	fmt.Println(i.installError())24}25import (26type install interface {27	installError() string28}29type installClass struct {30}31func (i *installClass) installError() string {32}33func main() {34	i := &installClass{err: "error"}35	fmt.Println(i.installError())36}37import (38type install interface {39	installError() string40}41type installClass struct {42}43func (i *installClass) installError() string {44}45func main() {46	i := &installClass{err: "error"}47	fmt.Println(i.installError())48}49import (50type install interface {51	installError() string52}53type installClass struct {54}55func (i *installClass) installError() string {56}57func main() {58	i := &installClass{err: "error"}59	fmt.Println(i.installError())60}61import (62type install interface {63	installError() string

1import (2func main() {3	i := install{}4	i.installError("Error installing")5}6import (7func main() {8	i := install{}9	i.installError("Error installing")10}11import (12func main() {13	i := install{}14	i.installError("Error installing")15}16import (17func main() {18	i := install{}19	i.installError("Error installing")20}21import (22func main() {23	i := install{}24	i.installError("Error installing")25}26import (27func main() {28	i := install{}29	i.installError("Error installing")30}31import (32func main() {33	i := install{}34	i.installError("Error installing")35}36import (37func main() {38	i := install{}39	i.installError("Error installing")40}41import (42func main() {43	i := install{}44	i.installError("Error installing")45}46import (47func main() {48	i := install{}49	i.installError("Error installing")50}51import (52func main() {53	i := install{}54	i.installError("Error installing")55}56import (57func main() {58	i := install{}59	i.installError("Error installing")60}

1import "fmt"2func main() {3    fmt.Println("Hello, playground")4    i := new(install)5    i.installError()6}7import "fmt"8func main() {9    fmt.Println("Hello, playground")10    i := &install{}11    i.installError()12}13import "fmt"14func main() {15    fmt.Println("Hello, playground")16    i := &install{}17    i.installError()18}19Your name to display (optional):20Your name to display (optional):

1installError installError = new installError();2installError.installError();3installError installError = new installError();4installError.installError();5installError installError = new installError();6installError.installError();7installError installError = new installError();8installError.installError();9installError installError = new installError();10installError.installError();11installError installError = new installError();12installError.installError();13installError installError = new installError();14installError.installError();15installError installError = new installError();16installError.installError();17installError installError = new installError();18installError.installError();19installError installError = new installError();20installError.installError();21installError installError = new installError();22installError.installError();23installError installError = new installError();24installError.installError();25installError installError = new installError();26installError.installError();27installError installError = new installError();28installError.installError();29installError installError = new installError();30installError.installError();31installError installError = new installError();32installError.installError();

1import (2func main() {3	installError()4}5import (6func installError() {7	fmt.Println(Error(message))8}9import (10func Error(message string) string {11}

1installError err = new installError();2err.installError("Error Message");3installSuccess suc = new installSuccess();4suc.installSuccess("Success Message");5installError err = new installError();6err.installError("Error Message");7installSuccess suc = new installSuccess();8suc.installSuccess("Success Message");9installError err = new installError();10err.installError("Error Message");11installSuccess suc = new installSuccess();12suc.installSuccess("Success Message");13installError err = new installError();14err.installError("Error Message");15installSuccess suc = new installSuccess();16suc.installSuccess("Success Message");17installError err = new installError();18err.installError("Error Message");19installSuccess suc = new installSuccess();20suc.installSuccess("Success Message");21installError err = new installError();22err.installError("Error Message");23installSuccess suc = new installSuccess();24suc.installSuccess("Success Message");25installError err = new installError();26err.installError("Error Message");27installSuccess suc = new installSuccess();28suc.installSuccess("Success Message");29installError err = new installError();30err.installError("Error Message");31installSuccess suc = new installSuccess();32suc.installSuccess("Success Message");33installError err = new installError();34err.installError("Error Message");