单元测试报错：参数数量错误（给定0，预期1..2）——控制器测试求助

Hey there, since you're new to Rails testing, this error is super common—let's break down the most likely causes and how to fix them step by step:

Common Culprits & Quick Fixes #

1. Forgetting Required Params in Test Requests #

Rails controller test methods like get, post, patch often need specific parameters to work with your controller actions. For example, if you're testing the show action (which fetches a single story), you must pass the id parameter of the story you want to load.

Wrong:

test "loads a story" do
  get :show # No ID passed here—Rails doesn't know which story to fetch!
  assert_response :success
end

Right:

test "loads a story" do
  # Pull a pre-defined story from your stories.yml fixture
  test_story = stories(:sample_story)
  # Pass the ID as a parameter
  get :show, params: { id: test_story.id }
  assert_response :success
end

2. Missing Params for Create/Update Actions #

If you're testing create or update, your controller probably expects a hash of story attributes. Skipping these will trigger the argument error too.

Wrong:

test "creates a story" do
  post :create # No story attributes provided!
  assert_redirected_to story_path(assigns(:story))
end

Right:

test "creates a story" do
  post :create, params: { 
    story: { title: "My First Story", content: "Testing is fun!" } 
  }
  assert_redirected_to story_path(assigns(:story))
end

3. Broken Controller Logic #

Double-check your stories_controller.rb to make sure none of your action methods are calling functions with missing arguments. For example, if you have a line like:

def show
  @story = Story.find() # Oops—no ID passed to find()!
end

That would throw exactly the error you're seeing. Fix it by using the parameter from the request:

def show
  @story = Story.find(params[:id])
end

4. Fixture Configuration Issues #

Take a quick look at your stories.yml to ensure all entries have the required fields your controller expects. If a fixture is missing a critical attribute, and your test tries to use it without supplementing the data, that could also cause problems.

If You're Still Stuck #

Share snippets of:

• The specific test in stories_controller_test.rb that's failing
• The corresponding action in stories_controller.rb
• A sample entry from stories.yml

That’ll help narrow down the exact issue!

内容的提问来源于stack exchange，提问作者thibault derennes