Create a post controller spec test - ruby-on-rails

Question

I am doing a controller test but it seems that spec.rb is wrong.
Do you have a suggestion ?
This is my posts_controller.rb:
class PostsController < ApplicationController
def create
#post = Post.new(post_params)
if #post.save
redirect_to #wall
end
end
def destroy
#post.destroy
end
private
def post_params
params.require(:post).permit(:wall, :content)
end
end
and this is my posts_controller_spec.rb:
require 'rails_helper'
describe PostsController do
let(:wall) { create(:wall) }
describe "#create" do
it "saves the new post in the wall" do
post :create, { wall_id: wall, content: "Some text I would like to put in my post" }
end
end
describe "#destroy" do
it "deletes the post in the wall" do
end
end
end
could you please help me to correct my spec.rb?
this is my error:
PostsController
#create
saves the new post in the wall (FAILED - 1)
#destroy
deletes the post in the wall
Failures:
1) PostsController#create saves the new post in the wall
Failure/Error: post :create, post: { wall: wall, content: "Some text I would like to put in my post" }
ActiveRecord::AssociationTypeMismatch:
Wall(#2159949860) expected, got String(#2155957040)
# ./app/controllers/posts_controller.rb:3:in create'
# ./spec/controllers/posts_controller_spec.rb:8:inblock (3 levels) in '
# -e:1:in `'
Finished in 0.9743 seconds (files took 3.94 seconds to load)
2 examples, 1 failure
Failed examples:
rspec ./spec/controllers/posts_controller_spec.rb:7 # PostsController#create saves the new post in the wall
Thank you in advance

Answer 1

Your spec doesn't include any expectations, so it's "wrong" in that sense. I suggest you google "RSpec expectations" and/or read the docs (i.e. https://relishapp.com/rspec/rspec-expectations/docs).
As for the error you mentioned in your comment, that reflects a problem with your production code (i.e. the lack of a redirect or render or some create template in the case the #post.save returns nil). Again, googling the error should yield information to help you address this problem or your can read http://guides.rubyonrails.org/layouts_and_rendering.html. If you're new to Rails entirely, I suggest following one of the tutorials, such as https://www.railstutorial.org/
You should also update your question to include that error information, since it's highly relevant and the question is essentially incomplete without it.

Answer 2

You should expect something on your tests. For example, you could do like this:
RSpec.describe PostsController, type: :controller do
let!(:wall) { create(:wall) }
let(:test_post) {
create(:post, wall_id: wall.id, content: "Something") }
}
describe "POST #create" do
let(:post) { assigns(:post) }
let(:test_wall) { create(:wall) }
context "when valid" do
before(:each) do
post :create, params: {
post: attributes_for(:post, wall_id: test_wall.id, content: "Anything")
}
end
it "should save the post" do
expect(post).to be_persisted
end
end
end
end
This way you are expecting a response from rails when you post you parameters. I just coded the post part of the test.