How to write an RSpec test for a simple PUT update

问题:

I'm trying to solidify my understanding of rails and the BDD workflow, so I wanted to start small by creating one of those mini-blogs, but with rspec. Right now I have an ArticlesController and Article model, and associated rspec files. Article is very simple, has just title:string and content:text, and the ArticlesController is RESTful - although I hand wrote the MCV for Article, it's basically the same as if I used a scaffold to create it.

However I don't really know what I'm doing when it comes to writing a test in rspec for the PUT update. I'm using Factory Girl to create the article object, and so far my code looks like:

#factories.rb
FactoryGirl.define do
  factory :article do
  title "a title"
  content "hello world"
end

#articles_controller_spec.rb
before(:each) do
  @article = Factory(:article)
end

describe "PUT 'update/:id'" do
  it "allows an article to be updated" do
    @attr = { :title => "new title", :content => "new content" }
    put :update, :id => @article.id, :article => @attr
    response.should be_successful
  end
end

However I keep getting:

Failures:
1) ArticlesController PUT 'update/:id' allows an article to be updated
   Failure/Error: response.should be_successful
     expected successful? to return true, got false

What am I doing wrong? And am I using the right tools? When I run my test server, New, Edit, Destroy all work as I would expect them to, so I'm guessing this is a problem with my understanding of RSpec. Let me know if I'm wrong - thanks!

回答1:

You forgot to .reload your @article, and on update action your response most likely perform redirect, so

RSpec 2:

describe "PUT update/:id" do
  let(:attr) do 
    { :title => 'new title', :content => 'new content' }
  end

  before(:each) do
    put :update, :id => @article.id, :article => attr
    @article.reload
  end

  it { response.should redirect_to(@article) }
  it { @article.title.should eql attr[:title] }
  it { @article.content.should eql attr[:content] }
end

Rspec 3:

describe "PUT update/:id" do
  let(:attr) do 
    { :title => 'new title', :content => 'new content' }
  end

  before(:each) do
    put :update, :id => @article.id, :article => attr
    @article.reload
  end

  it { expect(response).to redirect_to(@article) }
  it { expect(@article.title).to eql attr[:title] }
  it { expect(@article.content).to eql attr[:content] }
end

回答2:

When you are doing a PUT :update remember that you are editing an existing model, which you need to call in the put. Just pass your @article and update the attributes as follows.

describe "PUT 'update/:id'" do
  it "allows an article to be updated" do
    put :update, :id => @article.id, :article => @article.attributes = { :title => "new title", :content => "new content" }
    response.should be_successful
  end
end

回答3:

FactoryGirl.define :article do
  title "a title"
  content "hello world"
end

before(:each) do
  @article = Factory(:article)
end

it "should re-render edit template on failed update" do
  @attr = { :title => "", :content => "new content" }
  put :update, :id => @article.id, :article => @attr

  flash[:notice].should be_nil
  response.should render_template('edit')
end

it "should redirect to index with a notice on successful update" do
  @attr = { :title => "new title", :content => "new content" }
  put :update, :id => @article.id, :article => @attr

  assigns[:article].should_not be_new_record
  flash[:notice].should_not be_nil
  response.should redirect_to(:action => 'index')
end

回答4:

The way I like to test the update method is to just ensure that the updated_at time is greater than it was before. When you do this you can change the contents of the entire instance variable and still check if everything was updated. For instance:

describe "PUT 'update/:id'" do
  it "allows an article to be updated" do
    prev_updated_at = @article.updated_at
    @attr = { :title => "new title", :content => "new content" }
    put :update, :id => @article.id, :article => @attr
    @article.reload
    @article.updated_at.should != prev_updated_at 
  end
end