Trailing slash middleware with option to redirect

Signed-off-by: Vishal Rana <vr@labstack.com>

context_test.go

@@ -183,8 +183,8 @@ func TestContext(t *testing.T) {
 	rec = test.NewResponseRecorder()
 	c = NewContext(rq, rec, e)
 	assert.Equal(t, nil, c.Redirect(http.StatusMovedPermanently, "http://labstack.github.io/echo"))
-	assert.Equal(t, "http://labstack.github.io/echo", rec.Header().Get(HeaderLocation))
 	assert.Equal(t, http.StatusMovedPermanently, rec.Status())
+	assert.Equal(t, "http://labstack.github.io/echo", rec.Header().Get(HeaderLocation))
 
 	// Error
 	rec = test.NewResponseRecorder()

engine/engine.go

@@ -38,6 +38,9 @@ type (
 		// URI returns the unmodified `Request-URI` sent by the client.
 		URI() string
 
+		// SetURI sets the URI of the request.
+		SetURI(string)
+
 		// URL returns `engine.URL`.
 		URL() URL
 

engine/fasthttp/request.go

@@ -77,6 +77,11 @@ func (r *Request) URI() string {
 	return string(r.RequestURI())
 }
 
+// SetURI implements `engine.Request#SetURI` function.
+func (r *Request) SetURI(uri string) {
+	r.Request.Header.SetRequestURI(uri)
+}
+
 // Body implements `engine.Request#Body` function.
 func (r *Request) Body() io.Reader {
 	return bytes.NewBuffer(r.PostBody())

engine/standard/request.go

@@ -89,6 +89,11 @@ func (r *Request) URI() string {
 	return r.RequestURI
 }
 
+// SetURI implements `engine.Request#SetURI` function.
+func (r *Request) SetURI(uri string) {
+	r.RequestURI = uri
+}
+
 // Body implements `engine.Request#Body` function.
 func (r *Request) Body() io.Reader {
 	return r.Request.Body

middleware/slash.go

@@ -4,17 +4,39 @@ import (
 	"github.com/labstack/echo"
 )
 
+type (
+	// TrailingSlashConfig defines the config for TrailingSlash middleware.
+	TrailingSlashConfig struct {
+		// RedirectCode is the status code used when redirecting the request.
+		// Optional but when provided the request is redirected using this code.
+		RedirectCode int
+	}
+)
+
 // AddTrailingSlash returns a root level (before router) middleware which adds a
 // trailing slash to the request `URL#Path`.
 //
 // Usage `Echo#Pre(AddTrailingSlash())`
 func AddTrailingSlash() echo.MiddlewareFunc {
+	return AddTrailingSlashWithConfig(TrailingSlashConfig{})
+}
+
+// AddTrailingSlashWithConfig returns a AddTrailingSlash middleware from config.
+// See `AddTrailingSlash()`.
+func AddTrailingSlashWithConfig(config TrailingSlashConfig) echo.MiddlewareFunc {
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
-			url := c.Request().URL()
+			rq := c.Request()
+			url := rq.URL()
 			path := url.Path()
 			if path != "/" && path[len(path)-1] != '/' {
-				url.SetPath(path + "/")
+				path += "/"
+				uri := path + "?" + url.QueryString()
+				if config.RedirectCode != 0 {
+					return c.Redirect(config.RedirectCode, uri)
+				}
+				rq.SetURI(uri)
+				url.SetPath(path)
 			}
 			return next(c)
 		}
@@ -26,13 +48,26 @@ func AddTrailingSlash() echo.MiddlewareFunc {
 //
 // Usage `Echo#Pre(RemoveTrailingSlash())`
 func RemoveTrailingSlash() echo.MiddlewareFunc {
+	return RemoveTrailingSlashWithConfig(TrailingSlashConfig{})
+}
+
+// RemoveTrailingSlashWithConfig returns a RemoveTrailingSlash middleware from config.
+// See `RemoveTrailingSlash()`.
+func RemoveTrailingSlashWithConfig(config TrailingSlashConfig) echo.MiddlewareFunc {
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
-			url := c.Request().URL()
+			rq := c.Request()
+			url := rq.URL()
 			path := url.Path()
 			l := len(path) - 1
 			if path != "/" && path[l] == '/' {
-				url.SetPath(path[:l])
+				path = path[:l]
+				uri := path + "?" + url.QueryString()
+				if config.RedirectCode != 0 {
+					return c.Redirect(config.RedirectCode, uri)
+				}
+				rq.SetURI(uri)
+				url.SetPath(path)
 			}
 			return next(c)
 		}

middleware/slash_test.go

@@ -1,6 +1,7 @@
 package middleware
 
 import (
+	"net/http"
 	"testing"
 
 	"github.com/labstack/echo"
@@ -18,6 +19,17 @@ func TestAddTrailingSlash(t *testing.T) {
 	})
 	h(c)
 	assert.Equal(t, "/add-slash/", rq.URL().Path())
+
+	// With config
+	rq = test.NewRequest(echo.GET, "/add-slash?key=value", nil)
+	rc = test.NewResponseRecorder()
+	c = echo.NewContext(rq, rc, e)
+	h = AddTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})(func(c echo.Context) error {
+		return nil
+	})
+	h(c)
+	assert.Equal(t, http.StatusMovedPermanently, rc.Status())
+	assert.Equal(t, "/add-slash/?key=value", rc.Header().Get(echo.HeaderLocation))
 }
 
 func TestRemoveTrailingSlash(t *testing.T) {
@@ -30,4 +42,15 @@ func TestRemoveTrailingSlash(t *testing.T) {
 	})
 	h(c)
 	assert.Equal(t, "/remove-slash", rq.URL().Path())
+
+	// With config
+	rq = test.NewRequest(echo.GET, "/remove-slash/?key=value", nil)
+	rc = test.NewResponseRecorder()
+	c = echo.NewContext(rq, rc, e)
+	h = RemoveTrailingSlashWithConfig(TrailingSlashConfig{RedirectCode: http.StatusMovedPermanently})(func(c echo.Context) error {
+		return nil
+	})
+	h(c)
+	assert.Equal(t, http.StatusMovedPermanently, rc.Status())
+	assert.Equal(t, "/remove-slash?key=value", rc.Header().Get(echo.HeaderLocation))
 }

test/request.go

@@ -18,6 +18,7 @@ type (
 
 func NewRequest(method, url string, body io.Reader) engine.Request {
 	r, _ := http.NewRequest(method, url, body)
+	r.RequestURI = url
 	return &Request{
 		request: r,
 		url:     &URL{url: r.URL},
@@ -84,6 +85,10 @@ func (r *Request) URI() string {
 	return r.request.RequestURI
 }
 
+func (r *Request) SetURI(uri string) {
+	r.request.RequestURI = uri
+}
+
 func (r *Request) Body() io.Reader {
 	return r.request.Body
 }