user: add a service stub with validated register method

1 files changed, 134 insertions, 0 deletions

diff --git a/internal/user/service_test.go b/internal/user/service_test.go
new file mode 100644
index 0000000..938d2c3
--- /dev/null
+++ b/internal/user/service_test.go
@@ -0,0 +1,134 @@
+package user
+
+import (
+	"errors"
+	"log/slog"
+	"os"
+	"testing"
+
+	"golang.org/x/crypto/bcrypt"
+)
+
+func TestMain(m *testing.M) {
+	slog.SetDefault(slog.New(slog.DiscardHandler))
+	os.Exit(m.Run())
+}
+
+func NewTestUserService(t *testing.T) *Service {
+	t.Helper()
+	return &Service{repository: getEmptyRepository(), bcryptCost: bcrypt.MinCost}
+}
+
+func TestRegisterInputValidateFaultyData(t *testing.T) {
+	badInputs := getInvalidRegisterInputs()
+
+	for name, in := range badInputs {
+		t.Run(name, func(t *testing.T) {
+			err := in.validate()
+			if err == nil {
+				t.Errorf("bad input got through: %+v", in)
+			}
+			if !errors.Is(err, ErrInvalidInput) {
+				t.Errorf("unexpected error: got %v, want ErrInvalidInput", err)
+			}
+		})
+	}
+}
+
+func TestRegisterBadInput(t *testing.T) {
+	in := &RegisterInput{}
+	s := NewTestUserService(t)
+	_, err := s.Register(in)
+	if err == nil {
+		t.Error("no error when registering with faulty input")
+	}
+}
+
+func TestRegisterExistingUser(t *testing.T) {
+	r := getEmptyRepository()
+	r.fill()
+
+	badInputs := map[string]RegisterInput{
+		"existing username": {
+			Username: r.users[0].Username,
+			Email:    "thisemaildoesnt@exist.com",
+			Phone:    "123321",
+			Password: "22332233",
+		},
+		"existing email": {
+			Username: "thisusernamedoesntexist",
+			Email:    r.users[0].Email,
+			Phone:    "123321",
+			Password: "22332233",
+		},
+	}
+
+	for name, in := range badInputs {
+		t.Run(name, func(t *testing.T) {
+			s := &Service{repository: r, bcryptCost: bcrypt.MinCost}
+			_, err := s.Register(&in)
+			if err == nil {
+				t.Error("existing user registered")
+			}
+
+			if !errors.Is(err, ErrUserExists) {
+				t.Errorf("unexpected error: got %v, want ErrUserExists", err)
+			}
+		})
+	}
+}
+
+func TestRegisterRepositoryError(t *testing.T) {
+	s := &Service{repository: &RepositoryMock{err: errors.New("db down")}}
+	in := &RegisterInput{Username: "bob", Email: "b@b.com", Password: "thisissecure"}
+	_, err := s.Register(in)
+
+	if err == nil {
+		t.Error("register swallowed repository error")
+	}
+
+	if errors.Is(err, ErrUserExists) {
+		t.Error("repository failure reported as ErrUserExists")
+	}
+}
+
+func TestSuccessfulRegister(t *testing.T) {
+	s := NewTestUserService(t)
+	in := &RegisterInput{
+		Username: "happyuser123",
+		Email:    "happyuser@email.com",
+		Phone:    "+381233232",
+		Password: "supersecretpassword1234",
+	}
+	usr, err := s.Register(in)
+	if err != nil {
+		t.Errorf("register with good input failed: %+v", in)
+	}
+
+	err = bcrypt.CompareHashAndPassword([]byte(usr.passwordHash), []byte(in.Password))
+	if err != nil {
+		t.Errorf("hash and password compare error: %v", err)
+	}
+}
+
+func TestRegisterSameUserTwice(t *testing.T) {
+	s := NewTestUserService(t)
+	in := &RegisterInput{
+		Username: "happyuser123",
+		Email:    "happyuser@email.com",
+		Phone:    "+381233232",
+		Password: "supersecretpassword1234",
+	}
+
+	s.Register(in)
+
+	_, err := s.Register(in)
+	if err == nil {
+		t.Errorf("registered same user twice: %+v", in)
+	}
+
+	if !errors.Is(err, ErrUserExists) {
+		t.Errorf("unexpected error: got %v, want ErrUserExists", err)
+	}
+
+}