如何为使用Session的Rails 5控制器编写测试？实战场景求解

Hey there! Let's tackle this test case together since you're working through the Agile Web Development with Rails 5.1 book—great choice by the way!

First, we need to cover two key scenarios for your cart ownership validation: accessing a cart that belongs to the user's session (should work) and accessing a cart tied to someone else's session (should be blocked). We'll use Rails' built-in Minitest framework (which the book uses) for these tests.

These tests will live in test/controllers/carts_controller_test.rb.

Step 1: Setup Test Data #

First, add a setup method to create test carts and set up a valid session:

class CartsControllerTest < ActionDispatch::IntegrationTest
  setup do
    # Create two distinct carts
    @user_cart = Cart.create
    @foreign_cart = Cart.create
    # Link one cart to the test session
    session[:cart_id] = @user_cart.id
  end

Step 2: Test Accessing the User's Own Cart #

This test verifies that the user can successfully view their assigned cart:

test "should allow access to user's own cart" do
    get cart_url(@user_cart)
    # Check that the request succeeds
    assert_response :success
    # Optional: Confirm the correct cart is passed to the view
    assert_equal @user_cart, assigns(:cart)
  end

Step 3: Test Blocking Access to Foreign Carts #

This test ensures the user can't access a cart that doesn't match their session. Adjust the assertions based on what your invalid_cart method does (e.g., redirect, flash message, or 403 error):

test "should block access to foreign cart" do
    get cart_url(@foreign_cart)
    
    # If your invalid_cart redirects to the store with a flash message
    assert_redirected_to store_index_path
    assert_not_nil flash[:error] # Match the flash key you use in your controller
    
    # If you return a 403 Forbidden instead, use this line instead:
    # assert_response :forbidden
  end

Step 4: Wrap Up the Test Class #

Don't forget to close the class definition:

end

Quick Check for Your Controller Logic #

Since your original code was cut off, here's a polished version of the controller code to align with the tests:

class CartsController < ApplicationController
  def show
    @cart = Cart.find(params[:id])
    invalid_cart if @cart.id != session[:cart_id]
  end

  private

  def invalid_cart
    logger.error "Attempted access to invalid cart ##{params[:id]}"
    flash[:error] = "You don't have permission to access that cart!"
    redirect_to store_index_path
  end
end

Run your tests with rails test—they should pass if your controller logic is working as intended!

内容的提问来源于stack exchange，提问作者rderik