[RUBY] [RSpec] ArgumentError: wrong number of arguments If you get an error, you may have to worry about variable naming.

Introduction

controller specsThis is an article about. When I defined the variables for commonality, I decided to keep it as a memorandum because it got swamped if I named it properly!

environment

ruby 2.6.5 rails 5.2.4.2 rspec 3.7 capybara 2.15 factory_bot_rails 4.11

error contents

Code before error correction

spec/controllers/posts_controller_spec.rb

require 'rails_helper'

RSpec.describe PostsController, type: :controller do
  
  context "Actions that do not require login" do
  .
  .
  .
  end

  context "Actions that require login" do

    let(:user) { FactoryBot.create(:user) }
    let(:login_user) { login(user) }
    let(:post) { FactoryBot.create(:post) }
    let(:post_params) { FactoryBot.attributes_for(:post) }

    describe "create action" do

      context "For logged-in users" do
        it "Create a post" do
          login user
          expect {
            post :create, params: { post: post_params }
          }.to change(user.posts, :count).by(1)
        end
      end

      context "For users who are not logged in" do
      .
      .
      .
      end

    end
  end
end

Premise ➡︎ I'm using FactoryBot to create test data. (Post is associated) ➡︎ The login (user) method is defined in the rails_helper.rb file for login.

error contents

Failures:
  1)PostsController Actions that require login create Action For logged-in users Create a post
    Failure/Error: post :create, { post: post_params }
    
    ArgumentError:
      wrong number of arguments (given 2, expected 0)
　　　# ./spec/controllers/posts_controller_spec.rb:85:in `block (5 levels) in <main>'

The number of arguments on the caller (give) is 2, and the number of arguments on the method side (expected) is 0.

In other words, I am angry that "two arguments are called, but there is no corresponding argument on the method side".

Error point

post :create, params: { post: post_params }

The reason why this description causes an error is that the above "post: ``" part that I was supposed to pass as the `parameter key` is actually the key. It was caused by `, which was considered to be a `` post variable, which was defined to make posts common, not as.

The two gaves meant " post:` "and" post_params``` "...

So, I will change the naming of the `post variable" of the commoner so that the "post:" part can be recognized as a key. ```

solution

After code modification

spec/controllers/posts_controller_spec.rb

require 'rails_helper'

RSpec.describe PostsController, type: :controller do

  context "Actions that require login" do

    let(:user) { FactoryBot.create(:user) }
    let(:login_user) { login(user) }
    - let(:post) { FactoryBot.create(:post) } #Delete
    + let(:new_post) { FactoryBot.create(:post) } #Variable name change
    let(:post_params) { FactoryBot.attributes_for(:post) }

    describe "create action" do
      context "For logged-in users" do
        it "Create a post" do
          login user
          expect {
            post :create, params: { post: post_params }
          }.to change(user.posts, :count).by(1)
        end
      end
    end
  end
end

Rewrite the post variable to the new_post variable.

spec execution

$ bin/rspec spec/controllers

1 examples, 0 failures

I passed!

This error made me feel like I should be careful when naming variables ... lol

reference

https://qiita.com/yikegaya/items/98f0c12f5c25ee4731a1