fix(Context.Bind): should unescape special char in path

Other famous frameworks, such as expressjs or rails, will unescape the path params. We should follow the industry convention too.

bind.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"net/url"
 	"reflect"
 	"strconv"
 	"strings"
@@ -35,7 +36,12 @@ func (b *DefaultBinder) BindPathParams(c Context, i interface{}) error {
 	values := c.ParamValues()
 	params := map[string][]string{}
 	for i, name := range names {
-		params[name] = []string{values[i]}
+		escaped, err := url.QueryUnescape(values[i])
+		if err != nil {
+			return err
+		}
+
+		params[name] = []string{escaped}
 	}
 	if err := b.bindData(i, params, "param"); err != nil {
 		return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)

bind_test.go

@@ -468,6 +468,19 @@ func TestBindParam(t *testing.T) {
 		assert.Equal(t, "Jon Snow", u.Name)
 	}
 
+	// Bind param with escaped characters
+	{
+		c := e.NewContext(req, rec)
+		c.SetPath("/users/:name")
+		c.SetParamNames("name")
+		c.SetParamValues("John%2FSnow")
+
+		err := c.Bind(u)
+		if assert.NoError(t, err) {
+			assert.Equal(t, "John/Snow", u.Name)
+		}
+	}
+
 	// Second test for the absence of a param
 	c2 := e.NewContext(req, rec)
 	c2.SetPath("/users/:id")