app/repository/interfaces.go

@@ -51,3 +51,9 @@ type InteractionRepository interface {
 	// ListAllInteractions lists all interactions, sorted by creation date (descending)
 	ListAllInteractions() ([]model.Interaction, error)
 }
+
+type FollowerRepository interface {
+	Add(follower string) error
+	Remove(follower string) error
+	All() ([]string, error)
+}

infra/follower_repository.go

@@ -0,0 +1,57 @@
+package infra
+
+import (
+	"owl-blogs/app/repository"
+
+	"github.com/jmoiron/sqlx"
+)
+
+type sqlFollower struct {
+	Follwer string `db:"follower"`
+}
+
+type DefaultFollowerRepo struct {
+	db *sqlx.DB
+}
+
+func NewFollowerRepository(db Database) repository.FollowerRepository {
+	sqlxdb := db.Get()
+
+	// Create tables if not exists
+	sqlxdb.MustExec(`
+	CREATE TABLE IF NOT EXISTS followers (
+		follower TEXT PRIMARY KEY
+	);
+	`)
+
+	return &DefaultFollowerRepo{
+		db: sqlxdb,
+	}
+}
+
+// Add implements repository.FollowerRepository.
+func (d *DefaultFollowerRepo) Add(follower string) error {
+	_, err := d.db.Exec("INSERT INTO followers (follower) VALUES (?) ON CONFLICT DO NOTHING", follower)
+	return err
+}
+
+// Remove implements repository.FollowerRepository.
+func (d *DefaultFollowerRepo) Remove(follower string) error {
+	_, err := d.db.Exec("DELETE FROM followers WHERE follower = ?", follower)
+	return err
+}
+
+// All implements repository.FollowerRepository.
+func (d *DefaultFollowerRepo) All() ([]string, error) {
+	var followers []sqlFollower
+	err := d.db.Select(&followers, "SELECT * FROM followers")
+	if err != nil {
+		return nil, err
+	}
+
+	result := []string{}
+	for _, follower := range followers {
+		result = append(result, follower.Follwer)
+	}
+	return result, nil
+}

infra/follower_repository_test.go

@@ -0,0 +1,91 @@
+package infra_test
+
+import (
+	"owl-blogs/app/repository"
+	"owl-blogs/infra"
+	"owl-blogs/test"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func setupFollowerRepo() repository.FollowerRepository {
+	db := test.NewMockDb()
+	repo := infra.NewFollowerRepository(db)
+	return repo
+}
+
+func TestAddFollower(t *testing.T) {
+	repo := setupFollowerRepo()
+
+	err := repo.Add("foo@example.com")
+	require.NoError(t, err)
+
+	followers, err := repo.All()
+	require.NoError(t, err)
+	require.Len(t, followers, 1)
+	require.Equal(t, followers[0], "foo@example.com")
+}
+
+func TestDoubleAddFollower(t *testing.T) {
+	repo := setupFollowerRepo()
+
+	err := repo.Add("foo@example.com")
+	require.NoError(t, err)
+
+	err = repo.Add("foo@example.com")
+	require.NoError(t, err)
+
+	followers, err := repo.All()
+	require.NoError(t, err)
+	require.Len(t, followers, 1)
+	require.Equal(t, followers[0], "foo@example.com")
+}
+
+func TestMultipleAddFollower(t *testing.T) {
+	repo := setupFollowerRepo()
+
+	err := repo.Add("foo@example.com")
+	require.NoError(t, err)
+
+	err = repo.Add("bar@example.com")
+	require.NoError(t, err)
+
+	err = repo.Add("baz@example.com")
+	require.NoError(t, err)
+
+	followers, err := repo.All()
+	require.NoError(t, err)
+	require.Len(t, followers, 3)
+}
+
+func TestRemoveFollower(t *testing.T) {
+	repo := setupFollowerRepo()
+
+	err := repo.Add("foo@example.com")
+	require.NoError(t, err)
+
+	followers, err := repo.All()
+	require.NoError(t, err)
+	require.Len(t, followers, 1)
+
+	err = repo.Remove("foo@example.com")
+	require.NoError(t, err)
+
+	followers, err = repo.All()
+	require.NoError(t, err)
+	require.Len(t, followers, 0)
+
+}
+
+func TestRemoveNonExistingFollower(t *testing.T) {
+	repo := setupFollowerRepo()
+
+	err := repo.Remove("foo@example.com")
+	require.NoError(t, err)
+
+	followers, err := repo.All()
+	require.NoError(t, err)
+	require.Len(t, followers, 0)
+
+}