Merge pull request #3 from wawandco/task-moving-to-options

task: moving to the options pattern to configure the handler

README.md

@@ -30,29 +30,27 @@ And then using it accordingly in your app. See the Usage section for detailed in
 Maildoor instances satisfy the http.Handler interface and can be mounted into Mupliplexers. To initialize a Maildoor instance, use the New function:
 
 ```go
-auth, err := maildoor.New(maildoor.Options{
-    BaseURL: "http://localhost:8080",
-    Prefix: "/auth",
-
-    FinderFn:       finder,
-    AfterLoginFn:   afterLogin,
-    LogoutFn:       logout,
-
-    // Here we're using the SMTP sender but you can use your own.
-    SenderFn: maildoor.NewSMTPSender(maildoor.SMTPOptions{
-		From:     os.Getenv("SMTP_FROM_EMAIL"),
-		Host:     os.Getenv("SMTP_HOST"), // p.e. "smtp.gmail.com",
-		Port:     os.Getenv("SMTP_PORT"), //"587",
-		Password: os.Getenv("SMTP_PASSWORD"),
-	}),
-
-    CSRFTokenSecret: os.Getenv("SECRET_VALUE"),    
-    TokenManager: maildoor.DefaultTokenManager(os.Getenv("SECRET_VALUE")),
-})
-
-if err != nil {
-    return nil, fmt.Errorf("error initializing maildoor: %w", err)
-}
+	// Initialize the maildoor handler to take care of the web requests.
+	auth, err := maildoor.NewWithOptions(
+		os.Getenv("SECRET_KEY"),
+
+		maildoor.UseFinder(finder),
+		maildoor.UseAfterLogin(afterLogin),
+		maildoor.UseLogout(logout),
+		maildoor.UseTokenManager(maildoor.DefaultTokenManager(os.Getenv("SECRET_KEY"))),
+		maildoor.UseSender(
+			maildoor.NewSMTPSender(maildoor.SMTPOptions{
+				From:     os.Getenv("SMTP_FROM_EMAIL"),
+				Host:     os.Getenv("SMTP_HOST"), // p.e. "smtp.gmail.com",
+				Port:     os.Getenv("SMTP_PORT"), //"587",
+				Password: os.Getenv("SMTP_PASSWORD"),
+			}),
+		),
+	)
+
+    if err != nil {
+        return nil, fmt.Errorf("error initializing maildoor: %w", err)
+    }
 ```
 
 After initializing the Maildoor instance, you can mount it into a multiplexer:
@@ -72,9 +70,7 @@ After seeing how to initialize the Maildoor Instance, lets dig a deeper into wha
 
 #### FinderFn
 
-The finder function is used to find a user by email address. The logic for looking up users is up to the application developer, but it should return an `Emailable` instance to be used on the signin flow.
-
-The signature of the finder function is:
+The finder function is used to find a user by email address. The logic for looking up users is up to the application developer, but it should return an `Emailable` instance to be used on the signin flow. The signature of the finder function is:
 
 ```go
 func(string) (Emailable, error)

handler.go

@@ -13,7 +13,9 @@ type handler struct {
 	prefix          string
 	baseURL         string
 	csrfTokenSecret string
-	product         Product
+
+	// Product settings
+	product productConfig
 
 	finderFn     func(token string) (Emailable, error)
 	senderFn     func(message *Message) error

logger_test.go

@@ -40,10 +40,7 @@ func (sl *stringLogger) Errorf(format string, args ...interface{}) {
 
 func TestCustomLogger(t *testing.T) {
 	lg := &stringLogger{}
-	h, err := maildoor.New(maildoor.Options{
-		CSRFTokenSecret: "secret",
-		Logger:          lg,
-	})
+	h, err := maildoor.NewWithOptions("secret", maildoor.UseLogger(lg))
 
 	testhelpers.NoError(t, err)
 	w := httptest.NewRecorder()

login_test.go

@@ -11,9 +11,7 @@ import (
 )
 
 func TestLogin(t *testing.T) {
-	h, err := maildoor.New(maildoor.Options{
-		CSRFTokenSecret: "secret",
-	})
+	h, err := maildoor.NewWithOptions("secret")
 
 	testhelpers.NoError(t, err)
 

logout_test.go

@@ -10,14 +10,12 @@ import (
 )
 
 func TestLogout(t *testing.T) {
-	h, err := maildoor.New(maildoor.Options{
-		CSRFTokenSecret: "secret",
-		LogoutFn: func(w http.ResponseWriter, r *http.Request) error {
-			http.Redirect(w, r, "/", http.StatusSeeOther)
-			return nil
-		},
-	})
+	logout := func(w http.ResponseWriter, r *http.Request) error {
+		http.Redirect(w, r, "/", http.StatusSeeOther)
+		return nil
+	}
 
+	h, err := maildoor.NewWithOptions("secret", maildoor.UseLogout(logout))
 	testhelpers.NoError(t, err)
 
 	w := httptest.NewRecorder()

maildoor.go

@@ -19,7 +19,7 @@ var (
 	defaultPrefix       = "/auth"
 	defaultBaseURL      = "http://127.0.0.1:8080"
 	defaultTokenManager = DefaultTokenManager("not-so-secret-key")
-	defaultProduct      = Product{
+	defaultProduct      = productConfig{
 		Name:       "maildoor",
 		LogoURL:    "https://github.com/wawandco/maildoor/raw/main/images/maildoor_logo.png",
 		FaviconURL: "https://github.com/wawandco/maildoor/raw/main/images/favicon.png",
@@ -37,9 +37,7 @@ var (
 	assets embed.FS
 )
 
-// New maildoor handler with the given options, all of the options have defaults,
-// if not specified this method pulls the default value for them.
-func New(o Options) (*handler, error) {
+func NewWithOptions(csrfToken string, options ...Option) (*handler, error) {
 	h := &handler{
 		product: defaultProduct,
 		prefix:  defaultPrefix,
@@ -50,60 +48,16 @@ func New(o Options) (*handler, error) {
 		tokenManager: defaultTokenManager,
 		logger:       defaultLogger,
 
-		assetsServer: http.FileServer(http.FS(assets)),
+		assetsServer:    http.FileServer(http.FS(assets)),
+		csrfTokenSecret: csrfToken,
 	}
 
-	h.product.LogoURL = h.logoPath()
-	h.product.FaviconURL = h.faviconPath()
-
-	if o.CSRFTokenSecret == "" {
-		return nil, errors.New("CSRF Token secret is required")
-	}
-
-	h.csrfTokenSecret = o.CSRFTokenSecret
-
-	if o.Product != (Product{}) {
-		if o.Product.LogoURL == "" {
-			o.Product.LogoURL = h.logoPath()
-		}
-
-		if o.Product.FaviconURL == "" {
-			o.Product.FaviconURL = h.faviconPath()
-		}
-
-		h.product = o.Product
-	}
-
-	if o.Prefix != "" {
-		h.prefix = o.Prefix
-	}
-
-	if o.BaseURL != "" {
-		h.baseURL = o.BaseURL
-	}
-
-	if o.SenderFn != nil {
-		h.senderFn = o.SenderFn
-	}
-
-	if o.FinderFn != nil {
-		h.finderFn = o.FinderFn
-	}
-
-	if o.AfterLoginFn != nil {
-		h.afterLoginFn = o.AfterLoginFn
-	}
-
-	if o.LogoutFn != nil {
-		h.logoutFn = o.LogoutFn
-	}
-
-	if o.TokenManager != nil {
-		h.tokenManager = o.TokenManager
+	if csrfToken == "" {
+		return nil, errors.New("CSRF token is empty")
 	}
 
-	if o.Logger != nil {
-		h.logger = o.Logger
+	for _, option := range options {
+		option(h)
 	}
 
 	return h, nil

maildoor_test.go

@@ -9,21 +9,12 @@ import (
 func TestNew(t *testing.T) {
 	tcases := []struct {
 		name   string
-		opts   Options
+		opts   []Option
 		verify func(*testing.T, *handler, error)
 	}{
-		{
-			name: "totally empty it errors",
-			opts: Options{},
-			verify: func(t *testing.T, h *handler, err error) {
-				testhelpers.Error(t, err)
-			},
-		},
 		{
 			name: "empty defaults",
-			opts: Options{
-				CSRFTokenSecret: "secret",
-			},
+			opts: []Option{},
 			verify: func(t *testing.T, h *handler, err error) {
 				testhelpers.NoError(t, err)
 				testhelpers.NotEquals(t, "", h.product.Name)
@@ -39,13 +30,10 @@ func TestNew(t *testing.T) {
 
 		{
 			name: "some empty defaults",
-			opts: Options{
-				CSRFTokenSecret: "secret",
-				Product: Product{
-					Name:       "MyProduct",
-					LogoURL:    "logoURL",
-					FaviconURL: "faviconURL",
-				},
+			opts: []Option{
+				UseProductName("MyProduct"),
+				UseLogo("logoURL"),
+				UseFavicon("faviconURL"),
 			},
 			verify: func(t *testing.T, h *handler, err error) {
 				testhelpers.NoError(t, err)
@@ -71,9 +59,7 @@ func TestNew(t *testing.T) {
 		},
 		{
 			name: "product images",
-			opts: Options{
-				CSRFTokenSecret: "secret",
-			},
+			opts: []Option{},
 			verify: func(t *testing.T, h *handler, err error) {
 				testhelpers.NoError(t, err)
 				testhelpers.NotEquals(t, "", h.product.Name)
@@ -90,9 +76,14 @@ func TestNew(t *testing.T) {
 
 	for _, v := range tcases {
 		t.Run(v.name, func(tt *testing.T) {
-			h, err := New(v.opts)
+			h, err := NewWithOptions("secret", v.opts...)
 			v.verify(tt, h, err)
 		})
 	}
 
 }
+
+func TestEmptyToken(t *testing.T) {
+	_, err := NewWithOptions("")
+	testhelpers.Error(t, err)
+}

options.go

@@ -2,36 +2,84 @@ package maildoor
 
 import "net/http"
 
-// Options for the handler, these define the behavior of the
-// handler while running, cannot be changed after initialized.
-type Options struct {
-	Prefix  string
-	BaseURL string
-	Product Product
-
-	FinderFn     func(token string) (Emailable, error)
-	SenderFn     func(message *Message) error
-	AfterLoginFn func(w http.ResponseWriter, r *http.Request, user Emailable) error
-	LogoutFn     func(w http.ResponseWriter, r *http.Request) error
-
-	TokenManager TokenManager
-
-	// CSRFTokenSecret is used to generate signed CSRF tokens for the forms
-	// to be secure, it MUST be specified and is recommended to make it an
-	// environment variable or secret in application infrastructure,
-	// NOT in application code.
-	CSRFTokenSecret string
-
-	// Logger that the app uses, this by default is the default logger
-	// which prints using the std `log` package.
-	Logger Logger
-}
-
-// Product options allow to customize the product name and logo
-// as well as the favicon. These are used in the email that gets
-// sent to the user and the login form.
-type Product struct {
-	Name       string
-	LogoURL    string
-	FaviconURL string
+// Option is a function that can be passed to NewWithOptions to customize the
+// behavior of the handler.
+type Option func(*handler)
+
+// UseProductName to be used in emails and login form.
+func UseProductName(name string) Option {
+	return func(h *handler) {
+		h.product.Name = name
+	}
+}
+
+// UseLogo for the login form and email.
+func UseLogo(logoURL string) Option {
+	return func(h *handler) {
+		h.product.LogoURL = logoURL
+	}
+}
+
+// UseFavicon for the login form and email.
+func UseFavicon(faviconURL string) Option {
+	return func(h *handler) {
+		h.product.FaviconURL = faviconURL
+	}
+}
+
+// UseLogger across the lifecycle of the handler.
+func UseLogger(logger Logger) Option {
+	return func(h *handler) {
+		h.logger = logger
+	}
+}
+
+// UsePrefix sets the prefix for the handler, this is
+// useful for links and mounting the handler.
+func UsePrefix(prefix string) Option {
+	return func(h *handler) {
+		h.prefix = prefix
+	}
+}
+
+// UseBaseURL for links
+func UseBaseURL(baseURL string) Option {
+	return func(h *handler) {
+		h.baseURL = baseURL
+	}
+}
+
+// UseSender Specify the sender to be used by the handler.
+func UseSender(fn func(message *Message) error) Option {
+	return func(h *handler) {
+		h.senderFn = fn
+	}
+}
+
+// UseFinderFn sets the finder to be used.
+func UseFinder(fn func(token string) (Emailable, error)) Option {
+	return func(h *handler) {
+		h.finderFn = fn
+	}
+}
+
+// UseAfterLogin sets the function to be called after a successful login.
+func UseAfterLogin(fn func(w http.ResponseWriter, r *http.Request, user Emailable) error) Option {
+	return func(h *handler) {
+		h.afterLoginFn = fn
+	}
+}
+
+// UseLogout sets the function to be called after a successful logout.
+func UseLogout(fn func(w http.ResponseWriter, r *http.Request) error) Option {
+	return func(h *handler) {
+		h.logoutFn = fn
+	}
+}
+
+// UseTokenManager sets the token manager to be used.
+func UseTokenManager(tokenManager TokenManager) Option {
+	return func(h *handler) {
+		h.tokenManager = tokenManager
+	}
 }