🐛 [Bug]: CSRF middleware default ContextKey and PassLocalsToViews

[ly020044]

Bug Description

I'm using csrf middleware with v2.49.2 is worked. But after upgrade to v2.50.0, Errors will occur when visit any page.

failed to render: [Error (where: checkForValidIdentifiers)] context-key 'fiber.csrf.handler' (value: '&{config:0x14001198a00 sessionManager:<nil> storageManager:0x14000842e80}') is not a valid identifier

If change csrf config HandlerContextKey="csrf", is worked. Because HandlerContextKey is default value fiber.csrf.handle, So the default value contains the . character. .xx is usually used in templates to access properties or methods.

How to Reproduce

Steps to reproduce the behavior:

1. Set fiber.Config PassLocalsToViews: true
2. Use django html engine.
3. Use CSRF middleware

Expected Behavior

Can visit all pages.

Fiber Version

v2.50.0

Code Snippet (optional)

package main

import (
	"log"

	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/middleware/csrf"
	"github.com/gofiber/template/django/v3"
)

func main() {
	engine := django.New("./views", ".html")

	// Pass the engine to the Views
	app := fiber.New(fiber.Config{
		Views:             engine,
		PassLocalsToViews: true,
	})

	app.Use(csrf.New())

	app.Get("/", func(c *fiber.Ctx) error {
		// Render index
		return c.Render("index", fiber.Map{
			"Title": "Hello, World!",
		})
	})

	log.Fatal(app.Listen(":3000"))
}

Checklist:

• I agree to follow Fiber's Code of Conduct.
• I have checked for existing issues that describe my problem prior to opening this one.
• I understand that improperly formatted bug reports may be closed without explanation.

[ReneWerner87]

@sixcolors can you help here

[sixcolors]

@ly020044 I am looking into this now. It doesn't cause errors with any other supported fiber template engine.

[sixcolors]

gofiber/template/django/v3 will pass keys to Pongo2 that do not meet the regex in checkForValidIdentifiers()

The regex is:

var reIdentifiers = regexp.MustCompile("^[a-zA-Z0-9_]+$")

I have created a PR that will exclude any KVP that has an "invalid identifier".

Fixed in gofiber/template#307

[sixcolors]

I have submitted a proposal related to this issue: #2684