middleware/adaptor: allow to convert fiber.Ctx to (net/http).Request (#2461)

docs/api/middleware/adaptor.md

@@ -14,7 +14,8 @@ Converter for net/http handlers to/from Fiber request handlers, special thanks t
 | FiberHandler | `FiberHandler(h fiber.Handler) http.Handler` | fiber.Handler -> http.Handler
 | FiberHandlerFunc | `FiberHandlerFunc(h fiber.Handler) http.HandlerFunc` | fiber.Handler -> http.HandlerFunc
 | FiberApp | `FiberApp(app *fiber.App) http.HandlerFunc` | Fiber app -> http.HandlerFunc
-| CopyContextToFiberContex | `CopyContextToFiberContext(context interface{}, requestContext *fasthttp.RequestCtx)` | context.Context -> fasthttp.RequestCtx
+| ConvertRequest | `ConvertRequest(c *fiber.Ctx, forServer bool) (*http.Request, error)` | fiber.Ctx -> http.Request
+| CopyContextToFiberContext | `CopyContextToFiberContext(context interface{}, requestContext *fasthttp.RequestCtx)` | context.Context -> fasthttp.RequestCtx
 
 ## Examples
 
@@ -26,8 +27,8 @@ import (
 	"fmt"
 	"net/http"
 
-	"github.com/gofiber/v2/middleware/adaptor"
 	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/adaptor"
 )
 
 func main() {
@@ -61,8 +62,8 @@ import (
 	"log"
 	"net/http"
 
-	"github.com/gofiber/v2/middleware/adaptor"
 	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/adaptor"
 )
 
 func main() {
@@ -91,8 +92,8 @@ package main
 import (
 	"net/http"
 
-	"github.com/gofiber/v2/middleware/adaptor"
 	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/adaptor"
 )
 
 func main() {
@@ -116,10 +117,12 @@ func greet(c *fiber.Ctx) error {
 package main
 
 import (
-	"github.com/gofiber/v2/middleware/adaptor"
-	"github.com/gofiber/fiber/v2"
 	"net/http"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/adaptor"
 )
+
 func main() {
 	app := fiber.New()
 
@@ -133,3 +136,33 @@ func greet(c *fiber.Ctx) error {
 	return c.SendString("Hello World!")
 }
 ```
+
+### Fiber Context to (net/http).Request
+```go
+package main
+
+import (
+	"net/http"
+
+	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/middleware/adaptor"
+)
+
+func main() {
+	app := fiber.New()
+
+	app.Get("/greet", greetWithHTTPReq)
+
+	// Listen on port 3000
+	http.ListenAndServe(":3000", adaptor.FiberApp(app))
+}
+
+func greetWithHTTPReq(c *fiber.Ctx) error {
+	httpReq, err := adaptor.ConvertRequest(c, false)
+	if err != nil {
+		return err
+	}
+
+	return c.SendString("Request URL: " + httpReq.URL.String())
+}
+```

middleware/adaptor/adaptor.go

@@ -27,6 +27,16 @@ func HTTPHandler(h http.Handler) fiber.Handler {
 	}
 }
 
+// ConvertRequest converts a fiber.Ctx to an http.Request.
+// forServer should be set to true when the http.Request is going to be passed to a http.Handler.
+func ConvertRequest(c *fiber.Ctx, forServer bool) (*http.Request, error) {
+	var req http.Request
+	if err := fasthttpadaptor.ConvertRequest(c.Context(), &req, forServer); err != nil {
+		return nil, err //nolint:wrapcheck // This must not be wrapped
+	}
+	return &req, nil
+}
+
 // CopyContextToFiberContext copies the values of context.Context to a fasthttp.RequestCtx
 func CopyContextToFiberContext(context interface{}, requestContext *fasthttp.RequestCtx) {
 	contextValues := reflect.ValueOf(context).Elem()

middleware/adaptor/adaptor_test.go

@@ -7,11 +7,13 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"net/http/httptest"
 	"net/url"
 	"reflect"
 	"testing"
 
 	"github.com/gofiber/fiber/v2"
+	"github.com/gofiber/fiber/v2/utils"
 	"github.com/valyala/fasthttp"
 )
 
@@ -460,3 +462,26 @@ func (w *netHTTPResponseWriter) Write(p []byte) (int, error) {
 	w.body = append(w.body, p...)
 	return len(p), nil
 }
+
+func Test_ConvertRequest(t *testing.T) {
+	t.Parallel()
+
+	app := fiber.New()
+
+	app.Get("/test", func(c *fiber.Ctx) error {
+		httpReq, err := ConvertRequest(c, false)
+		if err != nil {
+			return err
+		}
+
+		return c.SendString("Request URL: " + httpReq.URL.String())
+	})
+
+	resp, err := app.Test(httptest.NewRequest(fiber.MethodGet, "/test?hello=world&another=test", http.NoBody))
+	utils.AssertEqual(t, nil, err, "app.Test(req)")
+	utils.AssertEqual(t, http.StatusOK, resp.StatusCode, "Status code")
+
+	body, err := io.ReadAll(resp.Body)
+	utils.AssertEqual(t, nil, err)
+	utils.AssertEqual(t, "Request URL: /test?hello=world&another=test", string(body))
+}