refactor: add the Identity type

Add a new Identity type with the required methods so that now the board
types (Card, Status and soon Tag) can automatically satisfy the BoltItem
interface.

internal/board/board.go

@@ -141,7 +141,7 @@ func (b *Board) CreateStatus(args StatusArgs) error {
 	}
 
 	status := Status{
-		ID:       -1,
+		Identity: Identity{ID: -1},
 		Name:     name,
 		Position: pos,
 		CardIds:  nil,
@@ -280,7 +280,7 @@ func (b *Board) CreateCard(args CardArgs) (int, error) {
 
 	boltItems := []db.BoltItem{
 		&Card{
-			ID:          -1,
+			Identity:    Identity{ID: -1},
 			Title:       args.NewTitle,
 			Description: args.NewDescription,
 			Created:     timestamp,

internal/board/card.go

@@ -2,29 +2,9 @@ package board
 
 // Card represents a card on a Kanban board.
 type Card struct {
-	ID          int
+	Identity
+
 	Title       string
 	Description string
 	Created     string
 }
-
-// SetID updates the ID of the Card value only if
-// the ID is < 1 (i.e. unset).
-func (c *Card) SetID(id int) error {
-	if id < 1 {
-		return InvalidIDError{id}
-	}
-
-	if c.ID > 0 {
-		return IDAlreadySetError{}
-	}
-
-	c.ID = id
-
-	return nil
-}
-
-// GetID returns the ID of the Card value.
-func (c *Card) GetID() int {
-	return c.ID
-}

internal/board/card_lifecycle_test.go

@@ -227,7 +227,7 @@ func testUpdateCard(kanban board.Board, modifiedCardArgs board.UpdateCardArgs, t
 		}
 
 		want := board.Card{
-			ID:          modifiedCardArgs.CardID,
+			Identity:    board.Identity{ID: modifiedCardArgs.CardID},
 			Title:       modifiedCardArgs.NewTitle,
 			Description: modifiedCardArgs.NewDescription,
 			Created:     timestamp,
@@ -255,7 +255,7 @@ func testUpdateCardContent(kanban board.Board, modifiedCardArgs board.UpdateCard
 		}
 
 		want := board.Card{
-			ID:          modifiedCardArgs.CardID,
+			Identity:    board.Identity{ID: modifiedCardArgs.CardID},
 			Title:       expectedTitle,
 			Description: expectedDescription,
 			Created:     timestamp,

internal/board/identity.go

@@ -0,0 +1,26 @@
+package board
+
+type Identity struct {
+	ID int
+}
+
+// SetID updates the ID value with a valid ID value
+// only if the ID is unset (i.e. < 1).
+func (i *Identity) SetID(id int) error {
+	if id < 1 {
+		return InvalidIDError{id}
+	}
+
+	if i.ID > 0 {
+		return IDAlreadySetError{}
+	}
+
+	i.ID = id
+
+	return nil
+}
+
+// GetID returns the ID value.
+func (i *Identity) GetID() int {
+	return i.ID
+}

internal/board/identity_test.go

@@ -3,20 +3,16 @@ package board_test
 import (
 	"errors"
 	"testing"
-	"time"
 
 	"codeflow.dananglin.me.uk/apollo/pelican/internal/board"
 )
 
-func TestCardSetInvalidID(t *testing.T) {
-	card := board.Card{
-		ID:          -1,
-		Title:       "Title",
-		Description: "Description",
-		Created:     time.Now().Format(time.DateTime),
+func TestSetInvalidID(t *testing.T) {
+	identity := board.Identity{
+		ID: -1,
 	}
 
-	err := card.SetID(-1000)
+	err := identity.SetID(-1000)
 
 	switch {
 	case err == nil:
@@ -29,14 +25,11 @@ func TestCardSetInvalidID(t *testing.T) {
 }
 
 func TestCardSetExistingID(t *testing.T) {
-	card := board.Card{
-		ID:          5,
-		Title:       "Title",
-		Description: "Description",
-		Created:     time.Now().Format(time.DateTime),
+	identity := board.Identity{
+		ID: 5,
 	}
 
-	err := card.SetID(10)
+	err := identity.SetID(10)
 
 	switch {
 	case err == nil:

internal/board/status.go

@@ -6,32 +6,13 @@ import (
 
 // Status represents the status of the Kanban board.
 type Status struct {
-	ID       int
+	Identity
+
 	Name     string
 	CardIds  []int
 	Position int
 }
 
-// UpdateID updates the ID of the Status value.
-func (s *Status) SetID(id int) error {
-	if id < 1 {
-		return InvalidIDError{id}
-	}
-
-	if s.ID > 0 {
-		return IDAlreadySetError{}
-	}
-
-	s.ID = id
-
-	return nil
-}
-
-// GetID returns the ID of the Status value.
-func (s *Status) GetID() int {
-	return s.ID
-}
-
 // AddCardID adds a card ID to the status' list of card IDs.
 func (s *Status) AddCardID(cardID int) {
 	// Create a new list if it does not exist
@@ -108,19 +89,19 @@ func (s ByStatusPosition) Less(i, j int) bool {
 func defaultStatusList() []Status {
 	return []Status{
 		{
-			ID:       -1,
+			Identity: Identity{-1},
 			Name:     "To Do",
 			Position: 1,
 			CardIds:  nil,
 		},
 		{
-			ID:       -1,
+			Identity: Identity{-1},
 			Name:     "Doing",
 			Position: 2,
 			CardIds:  nil,
 		},
 		{
-			ID:       -1,
+			Identity: Identity{-1},
 			Name:     "Done",
 			Position: 3,
 			CardIds:  nil,

internal/board/status_lifecycle_test.go

@@ -143,7 +143,7 @@ func testUpdateStatus(kanban board.Board, statusID, expectedPosition int, newNam
 		}
 
 		want := board.Status{
-			ID:       statusID,
+			Identity: board.Identity{ID: statusID},
 			Name:     newName,
 			CardIds:  nil,
 			Position: expectedPosition,

internal/db/database_test.go

@@ -45,25 +45,25 @@ func testCreateStatusList(t *testing.T, database *bolt.DB) {
 
 	newStatusList := []board.Status{
 		{
-			ID:       -1,
+			Identity: board.Identity{ID: -1},
 			Name:     "Backlog",
 			CardIds:  []int{1, 14, 9, 10},
 			Position: 1,
 		},
 		{
-			ID:       -1,
+			Identity: board.Identity{ID: -1},
 			Name:     "Next",
 			CardIds:  []int{2, 5, 12},
 			Position: 2,
 		},
 		{
-			ID:       -1,
+			Identity: board.Identity{ID: -1},
 			Name:     "In progress",
 			CardIds:  []int{3, 14},
 			Position: 3,
 		},
 		{
-			ID:       -1,
+			Identity: board.Identity{ID: -1},
 			Name:     "Finished!",
 			CardIds:  []int{4, 6, 7, 8, 11, 13},
 			Position: 4,
@@ -107,25 +107,25 @@ func testReadStatusList(t *testing.T, database *bolt.DB) {
 
 	want := []board.Status{
 		{
-			ID:       1,
+			Identity: board.Identity{ID: 1},
 			Name:     "Backlog",
 			CardIds:  []int{1, 14, 9, 10},
 			Position: 1,
 		},
 		{
-			ID:       2,
+			Identity: board.Identity{ID: 2},
 			Name:     "Next",
 			CardIds:  []int{2, 5, 12},
 			Position: 2,
 		},
 		{
-			ID:       3,
+			Identity: board.Identity{ID: 3},
 			Name:     "In progress",
 			CardIds:  []int{3, 14},
 			Position: 3,
 		},
 		{
-			ID:       4,
+			Identity: board.Identity{ID: 4},
 			Name:     "Finished!",
 			CardIds:  []int{4, 6, 7, 8, 11, 13},
 			Position: 4,
@@ -163,7 +163,7 @@ func TestReadAndWriteCards(t *testing.T) {
 	}()
 
 	singleCard := board.Card{
-		ID:          -1,
+		Identity:    board.Identity{ID: -1},
 		Title:       "A test task.",
 		Description: "This task should be completed.",
 	}
@@ -173,17 +173,17 @@ func TestReadAndWriteCards(t *testing.T) {
 
 	manyCards := []board.Card{
 		{
-			ID:          -1,
+			Identity:    board.Identity{ID: -1},
 			Title:       "Test card A.",
 			Description: "This is test card A.",
 		},
 		{
-			ID:          -1,
+			Identity:    board.Identity{ID: -1},
 			Title:       "Test card B.",
 			Description: "This is test card B.",
 		},
 		{
-			ID:          -1,
+			Identity:    board.Identity{ID: -1},
 			Title:       "Test card C.",
 			Description: "This is test card C.",
 		},
@@ -227,7 +227,7 @@ func testReadOneCard(t *testing.T, database *bolt.DB, cardID int) {
 	}
 
 	want := board.Card{
-		ID:          1,
+		Identity:    board.Identity{ID: 1},
 		Title:       "A test task.",
 		Description: "This task should be completed.",
 	}
@@ -282,17 +282,17 @@ func testReadManyCards(t *testing.T, database *bolt.DB, cardIDs []int) {
 
 	want := []board.Card{
 		{
-			ID:          2,
+			Identity:    board.Identity{ID: 2},
 			Title:       "Test card A.",
 			Description: "This is test card A.",
 		},
 		{
-			ID:          3,
+			Identity:    board.Identity{ID: 3},
 			Title:       "Test card B.",
 			Description: "This is test card B.",
 		},
 		{
-			ID:          4,
+			Identity:    board.Identity{ID: 4},
 			Title:       "Test card C.",
 			Description: "This is test card C.",
 		},
@@ -330,7 +330,7 @@ func TestDeleteOneCard(t *testing.T) {
 
 	// Create one card, get card ID.
 	card := board.Card{
-		ID:          -1,
+		Identity:    board.Identity{ID: -1},
 		Title:       "Test card",
 		Description: "",
 	}