Method ToMiddleware

middleware/slash.go:103–142

ToMiddleware converts RemoveTrailingSlashConfig to middleware or returns an error for invalid configuration

()

// ToMiddleware converts RemoveTrailingSlashConfig to middleware or returns an error for invalid configuration
func (config RemoveTrailingSlashConfig) ToMiddleware() (echo.MiddlewareFunc, error) {
	if config.Skipper == nil {
		config.Skipper = DefaultSkipper
	}
	if config.RedirectCode != 0 && (config.RedirectCode < http.StatusMultipleChoices || config.RedirectCode > http.StatusPermanentRedirect) {
		// this is same check as `echo.context.Redirect()` does, but we can check this before even serving the request.
		return nil, errors.New("invalid redirect code for remove trailing slash middleware")
	}

	return func(next echo.HandlerFunc) echo.HandlerFunc {
		return func(c *echo.Context) error {
			if config.Skipper(c) {
				return next(c)
			}

			req := c.Request()
			url := req.URL
			path := url.Path
			qs := c.QueryString()
			l := len(path) - 1
			if l > 0 && strings.HasSuffix(path, "/") {
				path = path[:l]
				uri := path
				if qs != "" {
					uri += "?" + qs
				}

				// Redirect
				if config.RedirectCode != 0 {
					return c.Redirect(config.RedirectCode, sanitizeURI(uri))
				}

				// Forward
				req.RequestURI = uri
				url.Path = path
			}
			return next(c)
		}
	}, nil
}

func sanitizeURI(uri string) string {
	// double slash `\\`, `//` or even `\/` is absolute uri for browsers and by redirecting request to that uri