RSpec：如何进行一个shared_example测试，以测试许多都更新不同属性的许多不同控制器PATCH请求？

Question

I have various controllers and I have tests for each one that test their update action. The tests have all the exact same structure: it tests if it a patch request will update and change the object, or not. The only difference between these tests are which attribute the tests check to see for its change assertion. These attributes are unique to the controllers.

class CarsController 

def update
   # update attribute
   ...
end

end

and

class DogsController 

def update
   # update attribute
   ...
end

end

My tests (2 of many more):

CarsSpec 
describe "PATCH" do
  it "should update the car" do
    expect do 
      patch :update, id: object.id, data: {make: "honda"}
    end.to change {object.reload.make}
  end
end

DogSpec 
describe "PATCH" do
  it "should update the dog" do
    expect do 
      patch :update, id: object.id, data: {breed: "husky"}
    end.to change {object.reload.breed}
  end
end

As you can see, they're the exact same structure of tests so naturally, to be DRY I want to extract them into a shared_example to be DRY. The idea is to have many more of these controllers but only actual test and that these controllers just pass in which field to update. It would involve something like

shared_example "update" do
  it "updates the object" do
    expect do 
      patch :update, id.object.id, data: { customField: "new value" }
    end.to change { object.reload.customField }
  end
end

Where customField could be either breed or make in this case and the test would know to update those fields so it is generic and can apply to many of these controllers. How can I achieve that or something similar?

Answer 1

shared_example 's block accepts arguments:

shared_example "update" do |custom_field|
  it "updates the object (field: #{custom_field})" do
    expect do 
      patch :update, id.object.id, data: { custom_field => "new value" }
    end.to change { object.reload.public_send(custom_field) }
  end
end

and call it as

include_examples 'update', :make
include_examples 'update', :breed