(feat): Add test coverage for layer.ExponentialBackoffLayerExecutor()

.gitignore

@@ -1,3 +1,2 @@
 /ebs-bootstrap*
-coverage.html
-coverage.out
+coverage.*

cmd/ebs-bootstrap.go

@@ -60,7 +60,7 @@ func main() {
 	}
 
 	// Layers
-	le := layer.NewExponentialBackoffLayerExecutor(c, dae)
+	le := layer.NewExponentialBackoffLayerExecutor(c, dae, layer.DefaultExponentialBackoffParameters())
 	layers := []layer.Layer{
 		layer.NewFormatDeviceLayer(db),
 		layer.NewLabelDeviceLayer(db),

internal/backend/file_test.go

@@ -282,7 +282,7 @@ func TestLinuxFileBackendFrom(t *testing.T) {
 				case "/mnt":
 					return &model.File{Path: p, Type: model.Directory}, nil
 				default:
-					return nil, utils.NotImeplementedError("GetFile()")
+					return nil, utils.NewNotImeplementedError("GetFile()")
 				}
 			},
 			ExpectedOutput: map[string]*model.File{
@@ -318,7 +318,7 @@ func TestLinuxFileBackendFrom(t *testing.T) {
 					counter++
 					return &model.File{Path: p, Type: model.Directory}, nil
 				default:
-					return nil, utils.NotImeplementedError("GetFile()")
+					return nil, utils.NewNotImeplementedError("GetFile()")
 				}
 			},
 			ExpectedOutput: map[string]*model.File{
@@ -355,7 +355,7 @@ func TestLinuxFileBackendFrom(t *testing.T) {
 				case "/mnt":
 					return &model.File{Path: "/mnt", Type: model.Directory}, nil
 				default:
-					return nil, utils.NotImeplementedError("GetFile()")
+					return nil, utils.NewNotImeplementedError("GetFile()")
 				}
 			},
 			ExpectedOutput: map[string]*model.File{

internal/layer/layer.go

@@ -10,12 +10,6 @@ import (
 	"github.com/reecetech/ebs-bootstrap/internal/config"
 )
 
-const (
-	InitialInterval = 200 * time.Millisecond
-	Multiplier      = 2
-	MaxRetries      = 3
-)
-
 const (
 	DisabledWarning = ""
 )
@@ -37,17 +31,36 @@ type ExponentialBackoffLayerExecutor struct {
 	config         *config.Config
 }
 
-func NewExponentialBackoffLayerExecutor(c *config.Config, ae action.ActionExecutor) *ExponentialBackoffLayerExecutor {
+type ExponentialBackoffParameters struct {
+	InitialInterval time.Duration
+	Multiplier      uint32
+	MaxRetries      uint32
+}
+
+func DefaultExponentialBackoffParameters() *ExponentialBackoffParameters {
+	return &ExponentialBackoffParameters{
+		InitialInterval: 200 * time.Millisecond,
+		Multiplier:      2,
+		MaxRetries:      3,
+	}
+}
+
+func NewExponentialBackoffLayerExecutor(c *config.Config, ae action.ActionExecutor, ebp *ExponentialBackoffParameters) *ExponentialBackoffLayerExecutor {
+	// Cast Multiplier and MaxRetries to float64 for use in the backoff calculation
+	m := float64(ebp.Multiplier)
+	mr := float64(ebp.MaxRetries)
+
+	// Create Backoff
 	bo := backoff.NewExponentialBackOff()
-	bo.InitialInterval = InitialInterval
+	bo.InitialInterval = ebp.InitialInterval
 	// Disable randomisation of the calculation of the next desired backoff duration
 	bo.RandomizationFactor = 0
 	// Set the multiplier for the exponential backoff, using the square root of the provided Multiplier.
-	bo.Multiplier = math.Sqrt(Multiplier)
+	bo.Multiplier = math.Sqrt(m)
 	// Calculate the maximum elapsed time for the backoff strategy based on the provided MaxRetries and InitialInterval.
 	// This formula calculates the maximum elapsed time as a geometric series sum for a given number of retries and interval.
-	bo.MaxElapsedTime = time.Duration((math.Pow(Multiplier, MaxRetries)-1)/(Multiplier-1)) * InitialInterval
-	bo.MaxInterval = InitialInterval * time.Duration(math.Pow(Multiplier, MaxRetries-1))
+	bo.MaxElapsedTime = time.Duration((math.Pow(m, mr)-1)/(m-1)) * ebp.InitialInterval
+	bo.MaxInterval = ebp.InitialInterval * time.Duration(math.Pow(m, mr-1))
 	return &ExponentialBackoffLayerExecutor{
 		backoff:        bo,
 		actionExecutor: ae,

internal/layer/layer_test.go

@@ -0,0 +1,118 @@
+package layer
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/reecetech/ebs-bootstrap/internal/action"
+	"github.com/reecetech/ebs-bootstrap/internal/config"
+	"github.com/reecetech/ebs-bootstrap/internal/utils"
+)
+
+const (
+	MaxUint32 = ^uint32(0)
+)
+
+type MockLayer struct {
+	from     *utils.MockIncrementError
+	modify   *utils.MockIncrementError
+	validate *utils.MockIncrementError
+}
+
+func (ml *MockLayer) From(c *config.Config) error {
+	return ml.from.Trigger()
+}
+
+func (ml *MockLayer) Modify(c *config.Config) ([]action.Action, error) {
+	err := ml.modify.Trigger()
+	if err != nil {
+		return nil, err
+	}
+	return []action.Action{}, nil
+}
+
+func (ml *MockLayer) Validate(c *config.Config) error {
+	return ml.validate.Trigger()
+}
+
+func (ml *MockLayer) Warning() string {
+	return DisabledWarning
+}
+
+func TestExponentialBackoffLayerExecutor(t *testing.T) {
+	mae := action.NewDefaultActionExecutor()
+	// Lets generate ExponentialBackoffParameters with a custom
+	// InitialInterval. We do not want to slow down the test suite
+	// with an excessively long initial interval
+	debp := DefaultExponentialBackoffParameters()
+	ebp := &ExponentialBackoffParameters{
+		InitialInterval: 1 * time.Millisecond,
+		Multiplier:      debp.Multiplier,
+		MaxRetries:      debp.MaxRetries,
+	}
+
+	subtests := []struct {
+		Name          string
+		From          *utils.MockIncrementError
+		Modify        *utils.MockIncrementError
+		Validate      *utils.MockIncrementError
+		ExpectedError error
+	}{
+		{
+			Name:          "Success",
+			From:          utils.NewMockIncrementError("From()", utils.SuccessUntilTrigger, MaxUint32),
+			Modify:        utils.NewMockIncrementError("Modify()", utils.SuccessUntilTrigger, MaxUint32),
+			Validate:      utils.NewMockIncrementError("Validate()", utils.SuccessUntilTrigger, MaxUint32),
+			ExpectedError: nil,
+		},
+		{
+			Name:          "From() - Failure on First Call",
+			From:          utils.NewMockIncrementError("From()", utils.SuccessUntilTrigger, 1),
+			Modify:        utils.NewMockIncrementError("Modify()", utils.SuccessUntilTrigger, MaxUint32),
+			Validate:      utils.NewMockIncrementError("Validate()", utils.SuccessUntilTrigger, MaxUint32),
+			ExpectedError: fmt.Errorf("🔴 From(): Type=SuccessUntilTrigger, Increment=1, Trigger=1"),
+		},
+		{
+			Name:          "From() - Trigger Permant Backoff Failure",
+			From:          utils.NewMockIncrementError("From()", utils.SuccessUntilTrigger, 2),
+			Modify:        utils.NewMockIncrementError("Modify()", utils.SuccessUntilTrigger, MaxUint32),
+			Validate:      utils.NewMockIncrementError("Validate()", utils.SuccessUntilTrigger, MaxUint32),
+			ExpectedError: fmt.Errorf("🔴 From(): Type=SuccessUntilTrigger, Increment=2, Trigger=2"),
+		},
+		{
+			Name:          "Modify() - Failure on First Call",
+			From:          utils.NewMockIncrementError("From()", utils.SuccessUntilTrigger, MaxUint32),
+			Modify:        utils.NewMockIncrementError("Modify()", utils.SuccessUntilTrigger, 1),
+			Validate:      utils.NewMockIncrementError("Validate()", utils.SuccessUntilTrigger, MaxUint32),
+			ExpectedError: fmt.Errorf("🔴 Modify(): Type=SuccessUntilTrigger, Increment=1, Trigger=1"),
+		},
+		// The number of times Validate() would be the initial call (1) plus the number of allowed retries (ebp.MaxRetries)
+		{
+			Name:          "Validate() - Success Just Before Maximum Retries Reached",
+			From:          utils.NewMockIncrementError("From()", utils.SuccessUntilTrigger, MaxUint32),
+			Modify:        utils.NewMockIncrementError("Modify()", utils.SuccessUntilTrigger, MaxUint32),
+			Validate:      utils.NewMockIncrementError("Validate()", utils.ErrorUntilTrigger, 1+ebp.MaxRetries),
+			ExpectedError: nil,
+		},
+		{
+			Name:          "Validate() - Trigger Maximum Retries",
+			From:          utils.NewMockIncrementError("From()", utils.SuccessUntilTrigger, MaxUint32),
+			Modify:        utils.NewMockIncrementError("Modify()", utils.SuccessUntilTrigger, MaxUint32),
+			Validate:      utils.NewMockIncrementError("Validate()", utils.ErrorUntilTrigger, 2+ebp.MaxRetries),
+			ExpectedError: fmt.Errorf("🔴 Validate(): Type=ErrorUntilTrigger, Increment=%d, Trigger=%d", 1+ebp.MaxRetries, 2+ebp.MaxRetries),
+		},
+	}
+	for _, subtest := range subtests {
+		t.Run(subtest.Name, func(t *testing.T) {
+			ml := &MockLayer{
+				from:     subtest.From,
+				modify:   subtest.Modify,
+				validate: subtest.Validate,
+			}
+			eb := NewExponentialBackoffLayerExecutor(nil, mae, ebp)
+			err := eb.Execute([]Layer{ml})
+			utils.CheckError("eb.Execute()", t, subtest.ExpectedError, err)
+		})
+	}
+}

internal/service/mock.go

@@ -16,19 +16,19 @@ type MockDeviceService struct {
 func NewMockDeviceService() *MockDeviceService {
 	return &MockDeviceService{
 		StubGetSize: func(name string) (uint64, error) {
-			return 0, utils.NotImeplementedError("GetSize()")
+			return 0, utils.NewNotImeplementedError("GetSize()")
 		},
 		StubGetBlockDevices: func() ([]string, error) {
-			return nil, utils.NotImeplementedError("GetBlockDevices()")
+			return nil, utils.NewNotImeplementedError("GetBlockDevices()")
 		},
 		StubGetBlockDevice: func(name string) (*model.BlockDevice, error) {
-			return nil, utils.NotImeplementedError("GetBlockDevice()")
+			return nil, utils.NewNotImeplementedError("GetBlockDevice()")
 		},
 		StubMount: func(source, target string, fs model.FileSystem, options model.MountOptions) error {
-			return utils.NotImeplementedError("Mount()")
+			return utils.NewNotImeplementedError("Mount()")
 		},
 		StubUmount: func(source, target string) error {
-			return utils.NotImeplementedError("Umount()")
+			return utils.NewNotImeplementedError("Umount()")
 		},
 	}
 }
@@ -63,16 +63,16 @@ type MockOwnerService struct {
 func NewMockOwnerService() *MockOwnerService {
 	return &MockOwnerService{
 		StubGetCurrentUser: func() (*model.User, error) {
-			return nil, utils.NotImeplementedError("GetCurrentUser()")
+			return nil, utils.NewNotImeplementedError("GetCurrentUser()")
 		},
 		StubGetCurrentGroup: func() (*model.Group, error) {
-			return nil, utils.NotImeplementedError("GetCurrentGroup()")
+			return nil, utils.NewNotImeplementedError("GetCurrentGroup()")
 		},
 		StubGetUser: func(usr string) (*model.User, error) {
-			return nil, utils.NotImeplementedError("GetUser()")
+			return nil, utils.NewNotImeplementedError("GetUser()")
 		},
 		StubGetGroup: func(grp string) (*model.Group, error) {
-			return nil, utils.NotImeplementedError("GetGroup()")
+			return nil, utils.NewNotImeplementedError("GetGroup()")
 		},
 	}
 }
@@ -100,7 +100,7 @@ type MockNVMeService struct {
 func NewMockNVMeService() *MockNVMeService {
 	return &MockNVMeService{
 		StubGetBlockDeviceMapping: func(device string) (string, error) {
-			return "", utils.NotImeplementedError("GetBlockDeviceMapping()")
+			return "", utils.NewNotImeplementedError("GetBlockDeviceMapping()")
 		},
 	}
 }
@@ -147,19 +147,19 @@ type MockFileSystemService struct {
 func NewMockFileSystemService() *MockFileSystemService {
 	return &MockFileSystemService{
 		StubGetSize: func(name string) (uint64, error) {
-			return 0, utils.NotImeplementedError("GetSize()")
+			return 0, utils.NewNotImeplementedError("GetSize()")
 		},
 		StubGetFileSystem: func() model.FileSystem {
 			return model.Unformatted
 		},
 		StubFormat: func(name string) error {
-			return utils.NotImeplementedError("Format()")
+			return utils.NewNotImeplementedError("Format()")
 		},
 		StubLabel: func(name string, label string) error {
-			return utils.NotImeplementedError("Label()")
+			return utils.NewNotImeplementedError("Label()")
 		},
 		StubResize: func(name string) error {
-			return utils.NotImeplementedError("Resize()")
+			return utils.NewNotImeplementedError("Resize()")
 		},
 		StubGetMaximumLabelLength: func() int {
 			return 0
@@ -215,16 +215,16 @@ type MockFileService struct {
 func NewMockFileService() *MockFileService {
 	return &MockFileService{
 		StubGetFile: func(file string) (*model.File, error) {
-			return nil, utils.NotImeplementedError("GetFile()")
+			return nil, utils.NewNotImeplementedError("GetFile()")
 		},
 		StubCreateDirectory: func(p string) error {
-			return utils.NotImeplementedError("CreateDirectory()")
+			return utils.NewNotImeplementedError("CreateDirectory()")
 		},
 		StubChangeOwner: func(p string, uid model.UserId, gid model.GroupId) error {
-			return utils.NotImeplementedError("ChangeOwner()")
+			return utils.NewNotImeplementedError("ChangeOwner()")
 		},
 		StubChangePermissions: func(p string, perms model.FilePermissions) error {
-			return utils.NotImeplementedError("ChangePermissions()")
+			return utils.NewNotImeplementedError("ChangePermissions()")
 		},
 	}
 }

internal/utils/exec.go

@@ -106,10 +106,9 @@ type ExecRunner struct {
 
 func NewExecRunner(binary Binary) *ExecRunner {
 	return &ExecRunner{
-		binary:      binary,
-		command:     exec.Command,
-		lookPath:    exec.LookPath,
-		isValidated: false,
+		binary:   binary,
+		command:  exec.Command,
+		lookPath: exec.LookPath,
 	}
 }
 

internal/utils/testing.go

@@ -8,8 +8,18 @@ import (
 	"github.com/ryanuber/go-glob"
 )
 
-func NotImeplementedError(id string) error {
-	return fmt.Errorf("🔴 %s is not implemented", id)
+type NotImeplementedError struct {
+	Id string
+}
+
+func NewNotImeplementedError(id string) *NotImeplementedError {
+	return &NotImeplementedError{
+		Id: id,
+	}
+}
+
+func (e *NotImeplementedError) Error() string {
+	return fmt.Sprintf("🔴 %s is not implemented", e.Id)
 }
 
 func CheckOutput(id string, t *testing.T, expected interface{}, actual interface{}, opts ...cmp.Option) {
@@ -64,3 +74,46 @@ func CheckErrorGlob(id string, t *testing.T, pattern error, actual error) {
 		}
 	}
 }
+
+type MockIncrementErrorType string
+
+const (
+	ErrorUntilTrigger   MockIncrementErrorType = "ErrorUntilTrigger"
+	SuccessUntilTrigger MockIncrementErrorType = "SuccessUntilTrigger"
+)
+
+type MockIncrementError struct {
+	id            string
+	mockErrorType MockIncrementErrorType
+	trigger       uint32
+	increment     uint32
+}
+
+func NewMockIncrementError(id string, errorType MockIncrementErrorType, trigger uint32) *MockIncrementError {
+	return &MockIncrementError{
+		id:            id,
+		mockErrorType: errorType,
+		trigger:       trigger,
+	}
+}
+
+func (mie *MockIncrementError) Error() string {
+	return fmt.Sprintf("🔴 %s: Type=%s, Increment=%d, Trigger=%d", mie.id, mie.mockErrorType, mie.increment, mie.trigger)
+}
+
+func (mie *MockIncrementError) Trigger() error {
+	mie.increment++
+	switch mie.mockErrorType {
+	case ErrorUntilTrigger:
+		if mie.increment < mie.trigger {
+			return mie
+		}
+	case SuccessUntilTrigger:
+		if mie.increment >= mie.trigger {
+			return mie
+		}
+	default:
+		return fmt.Errorf("🔴 An unsupported MockLayerErrorType was encountered")
+	}
+	return nil
+}