Rspec guidance on repetitive expect - ruby-on-rails

I have a test case like this.
subject(:report) { #report.data }
it { expect(report[0][:id]).to eq(#c1.id) }
it { expect(report[1][:id]).to eq(#c2.id) }
it { expect(report[2][:id]).to eq(#c3.id) }
it { expect(report[0][:title]).to eq("Announcement3") }
it { expect(report[1][:title]).to eq("Announcement2") }
it { expect(report[2][:title]).to eq("Announcement1") }
I feel this is not really an efficient way.
Is there any other way to make it efficient ? So that it looks like one line condition.

Test Behavior, Not Composition
Always test behavior, not composition. What you ought to be testing here is the behavior that given some set of fixed inputs, a report will generate the same fixed output every single time. You aren't doing that; you're introspecting individual report elements, which is about composition.
Instead, consider using fixtures or FactoryGirl (or even just a setup block) to define fixed inputs, and then check that:
it 'creates valid report data' do
expect(#report.data).to eq #sample.data
end
More on Behavior
If each element of your report is coming from a different method, you ought to be testing the behavior of each of those methods separately, rather than decomposing the final report. That is another way to make your test clearer and more meaningful, and addresses the "unit" in unit testing.

I'd rather write something like this:
it { expect(report[0]).to include(id: #c1.id, title: "Announcement3") }
it { expect(report[1]).to include(id: #c2.id, title: "Announcement2") }
it { expect(report[2]).to include(id: #c3.id, title: "Announcement1") }
It does not get that deep into report structure and for me looks more readable.

You could map reports to the keys you care about and make expectations on that:
expect(report.map { |h| h[:title] }).to eq [array, of, values]
You could use include to check each report member's keys:
expect(report[0]).to include id: #c1.id, title: "Announcement3"
You could build an "expected" object and test equality:
expected = [{ id: #c1.id, title: "Announcement3" }, ...]
expect(report).to eq expected

Related

2 expect blocks in Spock?

I have the following Spock test, which passes:
def "test"() {
given:
def name = "John"
expect:
name.length() == 4
when:
name = name.concat(name)
then:
name.length() == 8
}
But when I modify the last then block and make it an expect block...
// previous part same
expect:
name.length() == 8
I am getting:
Groovy-Eclipse: Groovy:'expect' is not allowed here; instead, use one of: [and, then]
Is it because multiple expect blocks are not allowed in a single test? If so, is this documented anywhere? There is a similar test here written with given - expect - when - then but it is not clear why a second expect was not used, although what is being asserted is same, just being flipped.
when-expect is simply a syntax error with regard to Spock's specification DSL. The compiler message already tells you how to solve your problem. After when you need then (or and first, if you want to structure your when block into multiple sections). In contrast, expect is a kind of when-then contracted into a single block, because both the stimulus and verifying the response in a condition appear together. Block labels and how to use them is documented here.
Under Specifications as Documentation, you learn more about why you might want to use and and block labels. Under Invocation Order you learn about what you can achieve by using multiple then blocks in contrast to then-and.
You can use multiple expect blocks within one feature, no problem. But you do need to make sure that your when-then (if any) is complete, before you can use another expect.
For example, this is a valid feature:
def "my feature"() {
given: true
and: true
and: true
expect: true
when: true
and: true
then: true
and: true
then: true
expect: true
and: true
cleanup: true
}

How do you make a feature method conditional

In my Test, I have some feature methods that only need to run in certain situations. My code looks something like this:
class MyTest extends GebReportingSpec{
def "Feature method 1"(){
when:
blah()
then:
doSomeStuff()
}
def "Feature method 2"(){
if(someCondition){
when:
blah()
then:
doSomeMoreStuff()
}
}
def "Feature method 3"(){
when:
blah()
then:
doTheFinalStuff()
}
}
I should note I am using a custom spock extension that allows me to run all feature methods of a spec even if a previous feature method fails.
The thing I just realized and the reason I am making this post, is because "Feature method 2" does not show up in my test results for some reason, but method 1 and 3 do. Even if someCondition is set to true, it does not appear in the build results. so I am wondering why this is, and how I can make this feature method conditional
Spock has special support for conditionally executing features, take a look at #IgnoreIf and #Requires.
#IgnoreIf({ os.windows })
def "I'll run everywhere but on Windows"() { ... }
You can also use static methods in the condition closure, they need to use the qualified version.
class MyTest extends GebReportingSpec {
#Requires({ MyTest.myCondition() })
def "I'll only run if myCondition() returns true"() { ... }
static boolean myCondition() { true }
}
Your test is not appearing in the report as you cant have the given, when, then blocks inside of a conditional.
You should always run the test but allow the test to fail gracefully:
Use the #FailsWith attribute. http://spockframework.org/spock/javadoc/1.0/spock/lang/FailsWith.html
#FailsWith(value = SpockAssertionError, reason = "Feature is not enabled")
def "Feature method 2"(){
when:
blah()
then:
doSomeMoreStuff()
}
Important to note that this test will be reported as passed when it fails with the specified exception. And it will also reported as passed if the feature is enabled and the test actually passed.
To Fix this I simply put a when/then block with a 10 ms sleep before the if statement and now that feature method is being executed

How do we test interactor organizers using rspec?

I want to test below organizer interactor for, calling the 2 specified interactors without executing the calling interactors('SaveRecord, PushToService') code.
class Create
include Interactor::Organizer
organize SaveRecord, PushToService
end
I found few examples where the overall result of all the interactors logic(record should be saved and pushed to other service) has been tested. But, i dont want to execute the other interactor's logic as they will be tested as part of their separate specs.
1. Is it possible to do so?
2. Which way of testing(testing the overall result/testing only this particular
organizer interactor behavior) is a better practise?
I believe we need to test the interactor organizer for included interactors without executing the included interacors. I am able to find a way stub and test the organizer with below lines
To Stub:
allow(SaveRecord).to receive(:call!) { :success }
allow(PushToService).to receive(:call!) { :success }
To Test:
it { expect(interactor).to be_kind_of(Interactor::Organizer) }
it { expect(described_class.organized).to eq([SaveRecord, PushToService]) }
Found call! method & organized variable from interactor organizer source files where it is trying to call and use internally. Stubbing the call! method and testing the organized variable has fulfilled my requirement.
You can test they are called and the order:
it 'calls the interactors' do
expect(SaveRecord).to receive(:call!).ordered
expect(PushToService).to receive(:call!).ordered
described_class.call
end
See: https://relishapp.com/rspec/rspec-mocks/docs/setting-constraints/message-order
Just iterating over #prem answer.
To Test:
it { expect(interactor).to be_kind_of(Interactor::Organizer) }
it { expect(described_class.organized).to eq([SaveRecord, PushToService]) }
interactor in this case is an instance of the Interactor class, or in Rspec syntax:
let(:interactor) { described_class.new }

rspec-mocks' doubles are designed to only last for one example

I've got a question about how to share rspec-mocks' double between examples. I'm writing a new rails app with rspec-mocks 3.1.3. I'm used to using the old (< 2.14 and and trying to update my knowledge if current rspec usage.
I have a model method:
def self.from_strava(activity_id, race_id, user)
#client ||= Strava::Api::V3::Client.new(access_token: 'abc123')
activity = #client.retrieve_an_activity(activity_id)
result_details = {race_id: race_id, user: user}
result_details[:duration] = activity['moving_time']
result_details[:date] = Date.parse(activity['start_date'])
result_details[:comment] = activity['description']
result_details[:strava_url] = "http://www.strava.com/activities/#{activity_id}"
Result.create!(result_details)
end
And here is the spec:
describe ".from_strava" do
let(:user) { FactoryGirl.build(:user) }
let(:client) { double(:client) }
let(:json_response) { JSON.parse(File.read('spec/support/strava_response.json')) }
before(:each) do
allow(Strava::Api::V3::Client).to receive(:new) { client }
allow(client).to receive(:retrieve_an_activity) { json_response }
allow(Result).to receive(:create!)
end
it "sets the duration" do
expect(Result).to receive(:create!).with(hash_including(duration: 3635))
Result.from_strava('123', 456, user)
end
it "sets the date" do
expect(Result).to receive(:create!).with(hash_including(date: Date.parse("2014-11-14")))
Result.from_strava('123', 456, user)
end
end
When I run a single test on it's own it's fine, but when I run the whole describe ".from_strava" block it fails with the message
Double :client was originally created in one example but has leaked into another example and can no longer be used. rspec-mocks' doubles are designed to only last for one example, and you need to create a new one in each example you wish to use it for.
I understand what it's saying, but surely this is an appropriate use of a double being used in 2 examples. After all, the client double isn't important to the example, it's just a way for me to load the canned response. I guess I could use WebMock but that seems very low-level and doesn't translate well to the actual code written. We should only be asserting one thing per example after all.
I had thought about replacing the client double with a call to
allow(Strava::Api::V3::Client).to receive_message_chain(:new, :retrieve_an_activity) { json_response }
but that doesn't seem to be the right approach either, given that the documentation states that receive_message_chain should be a code smell.
So if I shouldn't use receive_message_chain, shared client double and also follow the standard DRY principle then how should I fix this?
I would love some feedback on this.
Thanks,
Dave
Caching clients for external components can often be really desired (keeping alive connections/any SSL setup that you might need, etc.) and removing that for the sake of fixing an issue with tests is not a desirable solution.
In order to fix your test (without refactoring your code), you can do the following to clear the instance variable after each of your tests:
after { Result.instance_variable_set("#client", nil) }
While admittedly, this is not the cleanest solution, it seems to be the simplest and achieves both, lets you have a clear setup with no state shared in between tests, and keep your client cached in "normal" operation mode.
surely this is an appropriate use of a double being used in 2 examples.
No, it's not. :) You're trying to use a class variable; do not do that because the variable doesn't span examples. The solution is to set the client each time i.e. in each example.
Bad:
#client ||= Strava::Api::V3::Client.new(access_token: 'abc123')
Good:
#client = Strava::Api::V3::Client.new(access_token: 'abc123')
I had the same use case in an app of mine, and we solved it by extracting the cacheing into a private method and then stubbing that method to return the double (instead of stubbing the new method directly).
For example, in the class under test:
def self.from_strava(activity_id, race_id, user)
activity = strava_client.retrieve_an_activity(activity_id)
...
end
private
def self.strava_client
#client ||= Strava::Api::V3::Client.new(access_token: 'abc123')
end
And in the spec:
let(:client) { double(:client) }
before { allow(described_class).to receive(:strava_client).and_return(client) }
...
TLDR: Add after { order.vendor_service = nil } to balance the before block. Or read on...
I ran into this, and it was not obvious where it was coming from. In order_spec.rb model tests, I had this:
describe 'order history' do
before do
service = double('VendorAPI')
allow(service).to receive(:order_count).and_return(5)
order.vendor_service = service
end
# tests here ..
end
And in my Order model:
def too_many_orders?
##vendor_service ||= VendorAPI.new(key: 'abc', account: '123')
return ##vendor_service.order_count > 10
end
This worked fine when I only ran rspec on order_spec.rb
I was mocking something completely different in order_controller_spec.rb a little differently, using allow_any_instance_of() instead of double and allow:
allow_any_instance_of(Order).to receive(:too_many_orders?).and_return(true)
This, too, tested out fine.
The confounding trouble is that when I ran the full suite of tests, I got the OP's error on the controller mock -- the one using allow_any_instance. This was very hard to track down, as the problem (or at least my solution) lay in the model tests where I use double/allow.
To fix this, I added an after block clearing the class variable ##vendor_service, balancing the before block's action:
describe 'order history' do
before do
service = double('VendorAPI')
allow(service).to receive(:order_count).and_return(5)
order.vendor_service = service
end
after do
order.vendor_service = nil
end
# tests here ..
end
This forced the ||= VendorAPI.new() to use the real new function in later unrelated tests, not the mock object.

Avoid recreating the subject in RSpec

Say I have the following test
describe "bob" do
subject {
response = get "/expensive_lookup"
JSON.parse(response.body)
}
its(["transaction_id"]) { should == 1 }
its(["order_id"]) { should == 33 }
end
Then for each its() {} the subject will be reevaluated, which in my case it is a very slow lookup.
I could bundle all my tests together in one like
describe "bob" do
subject(res) {
response = get "/expensive_lookup"
JSON.parse(response.body)
}
it "returns the right stuff" do
res["transaction_id"]).should == 1
res["order_id"].should == 33
end
end
But this makes it less obvious which line of the test has failed if there is a failure.
Is there a way I can stop the subject from being reevaluated for each it block?
You can put that in to a before(:all) block. I don't know if that syntax has changed in a new rspec version, but regardless, your test would become this:
before(:all) do
response = get "/expensive_lookup"
#res = JSON.parse(response.body)
end
it "returns the right transaction ID" do
#res["transaction_id"].should == 1
end
# etc
The pro is that the code in the before-all block gets run just once for your spec. The con is that, as you can see, you can't take advantage of the subject; you need to write each more explicitly. Another gotcha is that any data saved to the test database is not part of the transaction and will not be rolled back.
There are two possible source of issues
Network request is slow/prone to fail
You should really mock all you network requests, slow or not.
The gem VCR is excellent. It makes it trivial to run your request once and persist the result for subsequent testing.
Building the immutable subject is slow
If you have multiple it blocks, the subject will be rebuild every time. Assuming you don't modify the subject, you can build it once.
You can use before(:all):
before(:all) { #cache = very_long_computation.freeze }
subject { #cache }
Note: that I call freeze to avoid modifying it by mistake, but of course that's not a deep freeze so you still need to mind what you are doing. If you are mutating your subject, your tests are no longer independent and shouldn't share the subject.

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