没有测试的代码就是耍流氓

1. rspec(1) - summary
2. specs(2) - model
3. specs(3) - controller
4. specs(4) - request
5. specs(5) - mock
6. [specs(6) - mailer]
7. [specs(7) - view]
8. [specs(8) - routing]
9. [specs(9) - helper]
10. [specs(10) - factory-girl]
11. [specs(11) - fake other gems]
12. [specs(12) - sidekiq]
13. [specs(13) - db migration]
14. [specs(14) - timecop]
15. [specs(15) - jenkins]

in general, we want to test our api, what should we do in rspec?

require "rails_helper"

RSpec.describe "User management", :type => :request do

  it "creates a User" do
    headers = {
      "ACCEPT" => "application/json",     # This is what Rails 4 accepts
      "HTTP_ACCEPT" => "application/json" # This is what Rails 3 accepts
    }
    lamda do
      post "/users", { user: {name: "zql"} }, headers
    end.should change(User, :count).by(1)

    expect(response.content_type).to eq("application/json")
    expect(response).to have_http_status(:created)

    user = User.last
    user.name.should eq "zql"
    # or 
    expect(user.name).to eq "zql"
  end

end

webmock

what should we do if we want to test external request?
a nice gem you can use, webmock
just like this(examples from webmock github):

stub_request(:post, "www.example.com").
  with(body: "abc", headers: { 'Content-Length' => 3 })
RestClient.post('www.example.com', "data[a]=1&data[b]=five",
  content_type: 'application/x-www-form-urlencoded')    # ===> Success

RestClient.post('www.example.com', '{"data":{"a":"1","b":"five"}}',
  content_type: 'application/json')    # ===> Success

RestClient.post('www.example.com', '<data a="1" b="five" />',
  content_type: 'application/xml')    # ===> Success

it's so easy to do this, right?

and more.

• match body

stub_request(:post, "www.example.com").
  with(body: hash_including({data: {a: '1', b: 'five'}}))

RestClient.post('www.example.com', "data[a]=1&data[b]=five&x=1",
:content_type => 'application/x-www-form-urlencoded')    # ===> Success

• match headers

stub_request(:any, "www.example.com").
  with(headers:{ 'Header-Name' => 'Header-Value' })

uri = URI.parse('http://www.example.com/')
req = Net::HTTP::Post.new(uri.path)
req['Header-Name'] = 'Header-Value'

res = Net::HTTP.start(uri.host, uri.port) do |http|
  http.request(req, 'abc')
end    # ===> Success

• auth required

stub_request(:get, "www.example.com").with(basic_auth: ['user', 'pass'])
# or
# stub_request(:get, "www.example.com").
#   with(headers: {'Authorization' => "Basic #{ Base64.strict_encode64('user:pass').chomp}"})

Net::HTTP.start('www.example.com') do |http|
  req = Net::HTTP::Get.new('/')
  req.basic_auth 'user', 'pass'
  http.request(req)
end    # ===> Success

please visit webmock if you wnat to more advange usage

but if we use gems like faraday or rest-client, so what should we should in rspec?
yeah, we want to mock a api request like mocking a model. here we go.

faraday

firstly, you should have a look at faraday testing, here are some example provided:

conn = Faraday::Adapter::Test::Stubs.new do |stub|
     stub.get('/ping') { |env| [200, {}, 'hello world!'] }
     stub.get('/other_url') { |env| [ 200, {}, 'hello, it's me, another test case' ]}
end
# or
cnnn = Faraday.new do |builder|
  builder.adapter :test, stubs do |stub|
    stub.get('/test') { |env| [ 200, {}, 'test case' ]}
  end
end

test request result

resp = test.get '/ping'
resp.status.should eq 200
resp.body.should eq 'hello world!'

resp = test.get '/other_url'
resp.status.should eq 200
resp.body.should eq 'hello, it's me, another test case'

file upload test

conn = Faraday.new('http://localhost') do |http|
  http.request :multipart
  http.request :url_encoded
  http.adapter :test, stubs do |stub|
     stub.post('/upload') { |env| [ 200, {}, {success: true, message: "upload successfully!"} ] }
  end
end

payload = { :file => Faraday::UploadIO.new('~/test.jpg', 'image/jpeg') }
resp = conn.post('/upload', payload)
resp.status.should eq 200
data = JSON.parse(resp.body)
data["success"].should eq true
data["message"].should eq "upload_successfully!"

rest-client

oh, you willl find this gem's test based on webmock.
it looks like this.

stub_request(:get, "www.example.com").to_return(:body => body, :status => 200)
    response = RestClient.get "www.example.com"
    expect(response.code).to eq 200
expect(response.body).to eq body

just do it as webmock.

done!