[authentication] user.CreatedAt uses timestamp type to write to db co…

…nsistently

authentication/api/user_signup.go

@@ -5,7 +5,6 @@ import (
 	"errors"
 	"log"
 	"net/http"
-	"time"
 
 	"github.com/bhongy/kimidori/authentication/user"
 )
@@ -20,9 +19,9 @@ type UserSignupRequest struct {
 }
 
 type UserSignupResponse struct {
-	ID        string    `json:"id"`
-	Username  string    `json:"username"`
-	CreatedAt time.Time `json:"createdAt"`
+	ID        string `json:"id"`
+	Username  string `json:"username"`
+	CreatedAt string `json:"createdAt"`
 }
 
 type userSignupHandler struct {
@@ -31,7 +30,9 @@ type userSignupHandler struct {
 
 func (h *userSignupHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodPost {
-		http.NotFound(w, r)
+		w.Header().Set("Allow", "POST")
+		code := http.StatusMethodNotAllowed
+		http.Error(w, http.StatusText(code), code)
 		return
 	}
 
@@ -64,7 +65,7 @@ func (h *userSignupHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	body, err := json.Marshal(UserSignupResponse{
 		ID:        u.ID,
 		Username:  u.Username,
-		CreatedAt: u.CreatedAt,
+		CreatedAt: u.CreatedAt.String(),
 	})
 
 	if err != nil {

authentication/api/user_signup_test.go

@@ -25,7 +25,7 @@ func TestUserSignup(t *testing.T) {
 	u := user.User{
 		ID:        "fake.id",
 		Username:  "fake.username",
-		CreatedAt: time.Now(),
+		CreatedAt: user.NewTimestamp(time.Now()),
 	}
 
 	body, err := json.Marshal(api.UserSignupRequest{
@@ -57,7 +57,7 @@ func TestUserSignup(t *testing.T) {
 		`{"id":"%v","username":"%v","createdAt":"%v"}`,
 		u.ID,
 		u.Username,
-		u.CreatedAt.Format(time.RFC3339Nano),
+		u.CreatedAt.String(),
 	)
 	if body := recorder.Body.String(); body != expectedBody {
 		t.Errorf("handler returned unexpected body: got %v want %v",

authentication/repository/mock/user_test.go

@@ -11,7 +11,7 @@ import (
 )
 
 var (
-	now = time.Now().Truncate(time.Millisecond)
+	now = user.NewTimestamp(time.Now())
 	u   = user.User{
 		ID:        "fake_user_id",
 		Username:  "fake_username",

authentication/repository/postgres/user_test.go

@@ -14,7 +14,7 @@ import (
 var (
 	// call `.Truncate` since the time is stored in db with a lower precision
 	// otherwise the assertion will result in a mismatch (in microseconds).
-	now = time.Now().Truncate(time.Millisecond)
+	now = user.NewTimestamp(time.Now())
 	u   = user.User{
 		ID:        "test_id",
 		Username:  "test_username",
@@ -71,7 +71,7 @@ func TestUserRepository_Create(t *testing.T) {
 			ID:        "fake_id_2",
 			Username:  u.Username,
 			Password:  "fake_password_2",
-			CreatedAt: time.Now(),
+			CreatedAt: user.NewTimestamp(time.Now()),
 		})
 		if err == nil {
 			t.Error("create user with duplicate username: expect error but got <nil>")

authentication/user/service.go

@@ -59,11 +59,12 @@ func (svc *service) Signup(username, password string) (User, error) {
 		return User{}, fmt.Errorf("hash password: %v", err)
 	}
 
+	timestamp := NewTimestamp(time.Now())
 	u := User{
 		ID:        ksuid.New().String(),
 		Username:  username,
 		Password:  p,
-		CreatedAt: time.Now().Truncate(time.Millisecond),
+		CreatedAt: timestamp,
 	}
 	err = svc.userRepo.Create(u)
 

authentication/user/timestamp.go

@@ -0,0 +1,36 @@
+package user
+
+import (
+	"fmt"
+	"time"
+)
+
+// we want to consistently format the time when serializing it
+// e.g. when saving it to DB or sending it over HTTP
+
+type timestamp time.Time
+
+func NewTimestamp(t time.Time) timestamp {
+	return timestamp(t)
+}
+
+// Equal allows tools like `cmp` to compare two timestamps for equality
+func (t timestamp) Equal(other timestamp) bool {
+	return t.String() == other.String()
+}
+
+// Scan implements Scanner interface supporting types: time.Time
+func (t *timestamp) Scan(v interface{}) error {
+	if v == nil {
+		return nil
+	}
+	if v, ok := v.(time.Time); ok {
+		*t = NewTimestamp(v)
+		return nil
+	}
+	return fmt.Errorf("Can not scan %v to timestamp", v)
+}
+
+func (t timestamp) String() string {
+	return time.Time(t).Format(time.RFC3339)
+}

authentication/user/timestamp_test.go

@@ -0,0 +1,40 @@
+package user_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/bhongy/kimidori/authentication/user"
+)
+
+const referenceTime = "2020-04-12T08:49:52Z"
+
+func newReferenceTime(t *testing.T) time.Time {
+	tt, err := time.Parse(time.RFC3339, referenceTime)
+	if err != nil {
+		t.Fatalf("Cannot parse time: %q", tt)
+	}
+	return tt
+}
+
+// TODO: test Equal method
+
+func Test_Timestamp_Scan(t *testing.T) {
+	ts := user.NewTimestamp(time.Now())
+	tt := newReferenceTime(t)
+	err := ts.Scan(tt)
+	if err != nil {
+		t.Error(err)
+	}
+	if got, want := ts.String(), referenceTime; got != want {
+		t.Errorf("Scanned value incorrect. want: %v, got: %v", got, want)
+	}
+}
+
+func Test_Timestamp_String(t *testing.T) {
+	tt := newReferenceTime(t)
+	ts := user.NewTimestamp(tt)
+	if formatted := ts.String(); formatted != referenceTime {
+		t.Error(formatted)
+	}
+}

authentication/user/user.go

@@ -1,11 +1,9 @@
 package user
 
-import "time"
-
 // User models a user account in an authentication context.
 type User struct {
 	ID        string
 	Username  string
 	Password  password // a hashed password as stored in the database
-	CreatedAt time.Time
+	CreatedAt timestamp
 }