Merge pull request #280 from xmidt-org/feature/simpler-middleware-opt…

…ions

simplified workflow setup for HTTP middleware

basculehttp/authenticator.go

@@ -0,0 +1,16 @@
+// SPDX-FileCopyrightText: 2024 Comcast Cable Communications Management, LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package basculehttp
+
+import (
+	"net/http"
+
+	"github.com/xmidt-org/bascule/v1"
+)
+
+// NewAuthenticator is a convenient wrapper around bascule.NewAuthenticator.
+// This function eases the syntactical pain of generics when creating Middleware.
+func NewAuthenticator(opts ...bascule.AuthenticatorOption[*http.Request]) (*bascule.Authenticator[*http.Request], error) {
+	return bascule.NewAuthenticator(opts...)
+}

basculehttp/authorizer.go

@@ -0,0 +1,16 @@
+// SPDX-FileCopyrightText: 2024 Comcast Cable Communications Management, LLC
+// SPDX-License-Identifier: Apache-2.0
+
+package basculehttp
+
+import (
+	"net/http"
+
+	"github.com/xmidt-org/bascule/v1"
+)
+
+// NewAuthorizer is a convenient wrapper around bascule.NewAuthorizer.
+// This function eases the syntactical pain of generics when creating Middleware.
+func NewAuthorizer(opts ...bascule.AuthorizerOption[*http.Request]) (*bascule.Authorizer[*http.Request], error) {
+	return bascule.NewAuthorizer(opts...)
+}

basculehttp/middleware.go

@@ -24,9 +24,22 @@ func (mof middlewareOptionFunc) apply(m *Middleware) error {
 
 // WithAuthenticator supplies the Authenticator workflow for the middleware.
 //
-// If no authenticator is supplied, NewMiddeware returns an error.
+// Note: If no authenticator is supplied, NewMiddeware returns an error.
 func WithAuthenticator(authenticator *bascule.Authenticator[*http.Request]) MiddlewareOption {
+	return UseAuthenticator(authenticator, nil)
+}
+
+// UseAuthenticator is a variant of WithAuthenticator that allows a caller to
+// nest function calls a little easier.  The output of NewAuthenticator
+// can be passed directly to this option.
+//
+// Note: If no authenticator is supplied, NewMiddeware returns an error.
+func UseAuthenticator(authenticator *bascule.Authenticator[*http.Request], err error) MiddlewareOption {
 	return middlewareOptionFunc(func(m *Middleware) error {
+		if err != nil {
+			return err
+		}
+
 		m.authenticator = authenticator
 		return nil
 	})
@@ -37,7 +50,18 @@ func WithAuthenticator(authenticator *bascule.Authenticator[*http.Request]) Midd
 // The Authorizer is optional.  If no authorizer is supplied, then no authorization
 // takes place and no authorization events are fired.
 func WithAuthorizer(authorizer *bascule.Authorizer[*http.Request]) MiddlewareOption {
+	return UseAuthorizer(authorizer, nil)
+}
+
+// UseAuthorizer is a variant of WithAuthorizer that allows a caller to
+// nest function calls a little easier.  The output of NewAuthorizer
+// can be passed directly to this option.
+func UseAuthorizer(authorizer *bascule.Authorizer[*http.Request], err error) MiddlewareOption {
 	return middlewareOptionFunc(func(m *Middleware) error {
+		if err != nil {
+			return err
+		}
+
 		m.authorizer = authorizer
 		return nil
 	})

basculehttp/middleware_examples_test.go

@@ -18,27 +18,22 @@ func ExampleMiddleware_basicauth() {
 		WithScheme(SchemeBasic, BasicTokenParser{}),
 	)
 
-	a, _ := bascule.NewAuthenticator(
-		bascule.WithTokenParsers(tp),
+	m, _ := NewMiddleware(
+		UseAuthenticator(
+			NewAuthenticator(
+				bascule.WithTokenParsers(tp),
+			),
+		),
 	)
 
-	m, err := NewMiddleware(
-		WithAuthenticator(a),
-	)
-
-	if err != nil {
-		panic(err)
-	}
-
 	// decorate a handler that needs authorization
 	h := m.ThenFunc(
 		func(response http.ResponseWriter, request *http.Request) {
-			t, ok := bascule.GetFrom(request)
-			if !ok {
-				panic("no token found")
+			if t, ok := bascule.GetFrom(request); ok {
+				fmt.Println("principal:", t.Principal())
+			} else {
+				fmt.Println("no token found")
 			}
-
-			fmt.Println("principal:", t.Principal())
 		},
 	)