Undefined method "Get" and "Let" with Rspec 3 - rails 4 - ruby-on-rails

Question

I've decided to start a new project using the new Rspec 3 (+ capybara/factory_girl) and am having trouble learning the new syntax. Right now I have
user_pages_spec.rb (Feature)
scenario "Signing Up" do
let(:submit) { "Sign up" }
scenario "With valid information" do
background do
fill_in "Username", with: "example"
fill_in "Email", with: "example#example.com"
fill_in "Password", with: "foobar123"
fill_in "Password confirmation", with: "foobar123"
end
scenario "should create a user" do
expect { click_button submit }.to change(User, :count).by(1)
end
end
end
Fails with undefined method 'let'. And:
static_pages_spec.rb (controller)
describe StaticPagesController do
describe "GET 'home'" do
it "returns http success" do
get :home
expect(response).to be_success
end
end
end
with "undefined method 'get'. (This is just the default controller spec)

Answer 1

When upgrading existing project from RSpec 2.x to 3.0 had same problem.
It was fixed for me with an explicit setting of the type.
Could you try this:
describe StaticPagesController, type: :controller do
EDIT:
I found now that the more structural cause and solution is that
in RSpec 3, I needed to add:
config.infer_spec_type_from_file_location!
in the config block in spec_helper.rb

Answer 2

You are getting undefined method let because capybara defines scenario an alias of it and feature as alias of describe. However, let is available in an example group context (a describe or context block) but not an individual example (and it block). So your example is equivalent to:
it "Signing Up" do
let(:submit) { "Sign up" }
it "With valid information" do
background do
fill_in "Username", with: "example"
fill_in "Email", with: "example#example.com"
fill_in "Password", with: "foobar123"
fill_in "Password confirmation", with: "foobar123"
end
it "should create a user" do
expect { click_button submit }.to change(User, :count).by(1)
end
end
end
...but should be:
feature "Signing Up" do
let(:submit) { "Sign up" }
context "With valid information" do
background do
fill_in "Username", with: "example"
fill_in "Email", with: "example#example.com"
fill_in "Password", with: "foobar123"
fill_in "Password confirmation", with: "foobar123"
end
scenario "should create a user" do
expect { click_button submit }.to change(User, :count).by(1)
end
end
end
Or, if you want to stick with pure RSpec constructs (rather than the capybara aliases):
describe "Signing Up" do
let(:submit) { "Sign up" }
context "With valid information" do
before do
fill_in "Username", with: "example"
fill_in "Email", with: "example#example.com"
fill_in "Password", with: "foobar123"
fill_in "Password confirmation", with: "foobar123"
end
it "should create a user" do
expect { click_button submit }.to change(User, :count).by(1)
end
end
end