Remove useless iot client interface (#101)

the large iot.Client interface was not a good idea: it added a level of indirection without bringing benefits
this pr removes a large interface from the producer side and implement few little interfaces on the consumers when needed, following the google guidelines https://github.com/golang/go/wiki/CodeReviewComments#interfaces

Author: polldo

Diff for: command/device/create.go

@@ -80,7 +80,7 @@ func Create(params *CreateParams) (*DeviceInfo, error) {
 
 	prov := &provision{
 		Commander: comm,
-		Client:    iotClient,
+		cert:      iotClient,
 		board:     board,
 		id:        dev.Id,
 	}

Diff for: command/device/createlora.go

@@ -171,7 +171,7 @@ func extractEUI(port string) (string, error) {
 	return eui, nil
 }
 
-func getDeviceLoraInfo(iotClient iot.Client, loraDev *iotclient.ArduinoLoradevicev1) (*DeviceLoraInfo, error) {
+func getDeviceLoraInfo(iotClient *iot.Client, loraDev *iotclient.ArduinoLoradevicev1) (*DeviceLoraInfo, error) {
 	dev, err := iotClient.DeviceShow(loraDev.DeviceId)
 	if err != nil {
 		return nil, fmt.Errorf("cannot retrieve device from the cloud: %w", err)

Diff for: command/device/provision.go

@@ -26,9 +26,9 @@ import (
 
 	"github.com/arduino/arduino-cloud-cli/arduino"
 	"github.com/arduino/arduino-cloud-cli/internal/binary"
-	"github.com/arduino/arduino-cloud-cli/internal/iot"
 	"github.com/arduino/arduino-cloud-cli/internal/serial"
 	"github.com/arduino/go-paths-helper"
+	iotclient "github.com/arduino/iot-client-go"
 	"github.com/sirupsen/logrus"
 )
 
@@ -63,11 +63,15 @@ func downloadProvisioningFile(fqbn string) (string, error) {
 	return p.String(), nil
 }
 
+type certificateCreator interface {
+	CertificateCreate(id, csr string) (*iotclient.ArduinoCompressedv2, error)
+}
+
 // provision is responsible for running the provisioning
 // procedures for boards with crypto-chip.
 type provision struct {
 	arduino.Commander
-	iot.Client
+	cert  certificateCreator
 	ser   *serial.Serial
 	board *board
 	id    string
@@ -125,7 +129,7 @@ func (p provision) configBoard() error {
 	if err != nil {
 		return err
 	}
-	cert, err := p.CertificateCreate(p.id, string(csr))
+	cert, err := p.cert.CertificateCreate(p.id, string(csr))
 	if err != nil {
 		return err
 	}

Diff for: command/ota/massupload.go

@@ -104,11 +104,15 @@ func MassUpload(params *MassUploadParams) ([]Result, error) {
 	return res, nil
 }
 
-func idsGivenTags(iotClient iot.Client, tags map[string]string) ([]string, error) {
+type deviceLister interface {
+	DeviceList(tags map[string]string) ([]iotclient.ArduinoDevicev2, error)
+}
+
+func idsGivenTags(lister deviceLister, tags map[string]string) ([]string, error) {
 	if tags == nil {
 		return nil, nil
 	}
-	devs, err := iotClient.DeviceList(tags)
+	devs, err := lister.DeviceList(tags)
 	if err != nil {
 		return nil, fmt.Errorf("%s: %w", "cannot retrieve devices from cloud", err)
 	}
@@ -119,8 +123,8 @@ func idsGivenTags(iotClient iot.Client, tags map[string]string) ([]string, error
 	return devices, nil
 }
 
-func validateDevices(iotClient iot.Client, ids []string, fqbn string) (valid []string, invalid []Result, err error) {
-	devs, err := iotClient.DeviceList(nil)
+func validateDevices(lister deviceLister, ids []string, fqbn string) (valid []string, invalid []Result, err error) {
+	devs, err := lister.DeviceList(nil)
 	if err != nil {
 		return nil, nil, fmt.Errorf("%s: %w", "cannot retrieve devices from cloud", err)
 	}
@@ -150,7 +154,11 @@ func validateDevices(iotClient iot.Client, ids []string, fqbn string) (valid []s
 	return valid, invalid, nil
 }
 
-func run(iotClient iot.Client, ids []string, otaFile string, expiration int) []Result {
+type otaUploader interface {
+	DeviceOTA(id string, file *os.File, expireMins int) error
+}
+
+func run(uploader otaUploader, ids []string, otaFile string, expiration int) []Result {
 	type job struct {
 		id   string
 		file *os.File
@@ -174,7 +182,7 @@ func run(iotClient iot.Client, ids []string, otaFile string, expiration int) []R
 	for i := 0; i < numConcurrentUploads; i++ {
 		go func() {
 			for job := range jobs {
-				err := iotClient.DeviceOTA(job.id, job.file, expiration)
+				err := uploader.DeviceOTA(job.id, job.file, expiration)
 				resCh <- Result{ID: job.id, Err: err}
 			}
 		}()

Diff for: command/ota/massupload_test.go

@@ -6,13 +6,19 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/arduino/arduino-cloud-cli/internal/iot/mocks"
 	iotclient "github.com/arduino/iot-client-go"
-	"github.com/stretchr/testify/mock"
 )
 
 const testFilename = "testdata/empty.bin"
 
+type deviceUploaderTest struct {
+	deviceOTA func(id string, file *os.File, expireMins int) error
+}
+
+func (d *deviceUploaderTest) DeviceOTA(id string, file *os.File, expireMins int) error {
+	return d.deviceOTA(id, file, expireMins)
+}
+
 func TestRun(t *testing.T) {
 	var (
 		failPrefix = "00000000"
@@ -23,14 +29,14 @@ func TestRun(t *testing.T) {
 		okID2      = okPrefix + "-003f-42f9-a80c-85a1de36753b"
 		okID3      = okPrefix + "-dac4-4a6a-80a4-698062fe2af5"
 	)
-	mockClient := &mocks.Client{}
-	mockDeviceOTA := func(id string, file *os.File, expireMins int) error {
-		if strings.Split(id, "-")[0] == failPrefix {
-			return errors.New("err")
-		}
-		return nil
+	mockClient := &deviceUploaderTest{
+		deviceOTA: func(id string, file *os.File, expireMins int) error {
+			if strings.Split(id, "-")[0] == failPrefix {
+				return errors.New("err")
+			}
+			return nil
+		},
 	}
-	mockClient.On("DeviceOTA", mock.Anything, mock.Anything, mock.Anything).Return(mockDeviceOTA, nil)
 
 	devs := []string{okID1, failID1, okID2, failID2, okID3}
 	res := run(mockClient, devs, testFilename, 0)
@@ -49,6 +55,14 @@ func TestRun(t *testing.T) {
 	}
 }
 
+type deviceListerTest struct {
+	list []iotclient.ArduinoDevicev2
+}
+
+func (d *deviceListerTest) DeviceList(tags map[string]string) ([]iotclient.ArduinoDevicev2, error) {
+	return d.list, nil
+}
+
 func TestValidateDevices(t *testing.T) {
 	var (
 		correctFQBN = "arduino:samd:nano_33_iot"
@@ -60,23 +74,21 @@ func TestValidateDevices(t *testing.T) {
 		idNotFound = "deb17b7f-b39d-47a2-adf3-d26cdf474707"
 	)
 
-	mockClient := &mocks.Client{}
-	mockDeviceList := func(tags map[string]string) []iotclient.ArduinoDevicev2 {
-		return []iotclient.ArduinoDevicev2{
+	mockDeviceList := deviceListerTest{
+		list: []iotclient.ArduinoDevicev2{
 			{Id: idCorrect1, Fqbn: correctFQBN},
 			{Id: idCorrect2, Fqbn: correctFQBN},
 			{Id: idNotValid, Fqbn: wrongFQBN},
-		}
+		},
 	}
-	mockClient.On("DeviceList", mock.Anything).Return(mockDeviceList, nil)
 
 	ids := []string{
 		idCorrect1,
 		idNotFound,
 		idCorrect2,
 		idNotValid,
 	}
-	v, i, err := validateDevices(mockClient, ids, correctFQBN)
+	v, i, err := validateDevices(&mockDeviceList, ids, correctFQBN)
 	if err != nil {
 		t.Errorf("unexpected error: %s", err.Error())
 	}

Diff for: command/thing/clone.go

@@ -61,8 +61,12 @@ func Clone(params *CloneParams) (*ThingInfo, error) {
 	return t, nil
 }
 
-func retrieve(client iot.Client, thingID string) (*iotclient.ThingCreate, error) {
-	clone, err := client.ThingShow(thingID)
+type thingFetcher interface {
+	ThingShow(id string) (*iotclient.ArduinoThing, error)
+}
+
+func retrieve(fetcher thingFetcher, thingID string) (*iotclient.ThingCreate, error) {
+	clone, err := fetcher.ThingShow(thingID)
 	if err != nil {
 		return nil, fmt.Errorf("%s: %w", "retrieving the thing to be cloned", err)
 	}