I'm writing some tests for my backend jobs and I'm having a weird issue with rspec not finding my methods.
I wrote a simple class & test to illustrate the issue :
app/interactors/tmp_test.rb :
class TmpTest
def call
a = 10
b = 5
b.substract_two
return a + b
end
def substract_two
c = self - 2
return c
end
end
spec/interactors/tmp_test.rb :
require 'rails_helper'
describe TmpTest do
context 'when doing the substraction' do
it 'return the correct number' do
expect(described_class.call).to eq(13)
end
end
end
output:
TmpTest
when doing the substraction
return the correct number (FAILED - 1)
Failures:
1) TmpTest when doing the substraction return the correct number
Failure/Error: expect(described_class.call).to eq(13)
NoMethodError:
undefined method `call' for TmpTest:Class
# ./spec/interactors/tmp_test.rb:6:in `block (3 levels) in <top (required)>'
Finished in 0.00177 seconds (files took 1.93 seconds to load)
1 example, 1 failure
Failed examples:
rspec ./spec/interactors/tmp_test.rb:5 # TmpTest when doing the substraction return the correct number
It's not a class method, it's an instance method. Your test should look like this:
describe TmpTest do
subject(:instance) { described_class.new }
context 'when doing the subtraction' do
it 'returns the correct number' do
expect(instance.call).to eq(13)
end
end
end
This is a complete mess. Corrected version with comments:
class TmpTest
def call
a = 10
b = 5
# b.substract_two # why do you call method of this class on b?!
a + subtract_two(b)
end
def substract_two(from)
from - 2
end
end
Also: don’t use return in the very last line of the method.
Related
The class being tested qa.rb contains the code:
class QA
def initialize(bugs: 0)
#bugs = bugs
end
def speak
"Hello!"
end
def happy?
#bugs > 0
end
def debug
#bugs = 0
end
end
The RSpec file qa_spec.rb contains the code:
require 'rspec'
require_relative 'qa'
RSpec.describe QA do
describe '#happy?' do
context 'when bugs are more than 0' do
it 'returns true' do
subject { described_class.new(bugs: 1) }
expect(subject).to be_happy
end
end
end
end
The test fails when I run it, and gives me this error:
PS C:\Users\Jobla\repos\TDD> rspec qa_spec.rb
F
Failures:
1) QA#happy? when bugs are more than 0 returns true
Failure/Error: expect(subject).to be_happy
expected `#<QA:0x2e0d640 #bugs=0>.happy?` to return true, got false
# ./qa_spec.rb:9:in `block (4 levels) in <top (required)>'
Finished in 0.02999 seconds (files took 0.16995 seconds to load)
1 example, 1 failure
Failed examples:
rspec ./qa_spec.rb:7 # QA#happy? when bugs are more than 0 returns true
However, when I edit qa_spec.rb and I swap the it and subject lines, the test suddenly passes:
require 'rspec'
require_relative 'qa'
RSpec.describe QA do
describe '#happy?' do
context 'when bugs are more than 0' do
subject { described_class.new(bugs: 1) } #swapped with line below
it 'returns true' do #swapped with line above
expect(subject).to be_happy
end
end
end
end
Tests pass:
PS C:\Users\Jobla\repos\TDD> rspec qa_spec.rb
.
Finished in 0.01003 seconds (files took 0.17993 seconds to load)
1 example, 0 failures
Please could someone explain why does swapping the it and subject lines change the result of the test?
subject is designed to be set in context or describe block, but not in it.
If you do not set subject before it then subject would be set automatically by calling new without parameters on described_class. bugs will be set to default 0. After that, you call it with a block subject { described_class.new(bugs: 1) } inside it, it's the same as if you call described_class.new { described_class.new(bugs: 1) } because subject inside it is an instance of QA class.
I want to check whether the block is called in my function using rspec. Below is my code:
class SP
def speak(options={},&block)
puts "speak called"
block.call()
rescue ZeroDivisionError => e
end
end
describe SP do
it "testing speak functionality can receive a block" do
sp = SP.new
def test_func
a = 1
end
sp_mock = double(sp)
expect(sp_mock).to receive(:speak).with(test_func)
sp.speak(test_func)
end
end
Below is my error:
SP testing speak functionality can receive a block
Failure/Error: block.call()
NoMethodError:
undefined method `call' for nil:NilClass
# ./test.rb:9:in `speak'
# ./test.rb:25:in `block (2 levels) in <top (required)>'
Could you please help. I spent lots of time in that.
You have to use one of RSpec's yield matcher:
describe SP do
it "testing speak functionality can receive a block" do
sp = SP.new
expect { |b| sp.speak(&b) }.to yield_control
end
end
I think Stefan provided the best answer. However I wanted to point out that you should be testing the behaviour of the code instead of implementation details.
describe SP do
it "testing speak functionality can receive a block" do
sp = SP.new
called = false
test_func = -> () { called = true }
sp.speak(&test_func)
expect(called).to eql(true)
end
end
How do you create a rspec method stub to allow a response from a method that takes in the hash key to return its value?
This is the line I want to test
sub_total = menu.menu_items[item] * quantity
and I'm using this line in rspec as my test stub on a double.
allow(menu).to receive(:menu_items[item]).and_return(2.0)
My env is set up with ruby 2.2.0 and spec 3.1.7
However I keep on getting a
NameError: undefined local variable or method `item'
Ruby code
def place_order(item, quantity, menu)
sub_total = menu.menu_items[item] * quantity
#customer_order << [item, quantity, sub_total]
end
Rspec code
let(:menu) { double :menu }
it "should allow 1 order of beer to placed" do
order = Order.new
allow(menu).to receive(:menu_items[item]).and_return(2.0)
order.place_order(:Beer, 1, 2.0)
expect(order.customer_order).to eq [[:Beer, 1, 2.0]]
end
Failures:
1) Order should allow 1 order of beer to placed
Failure/Error: allow(menu).to receive(:menu_items[item]).and_return(2.0)
NameError:
undefined local variable or method `item' for #<RSpec::ExampleGroups::Order:0x007fbb62917ee8 #__memoized=nil>
# ./spec/order_spec.rb:9:in `block (2 levels) in <top (required)>'
I've tried a number of things but nothing has worked
allow(menu).to receive(:menu_items).and_return(2.0)
allow(menu).to receive(:menu_items).with(item).and_return(2.0)
allow(menu).to receive(:menu_items).with("item").and_return(2.0)
allow(menu).to receive(:menu_items).with([item]).and_return(2.0)
I've run my code in irb and I can see it works but I can't find a way to get my class double to recerive the hash key.
you can do this:
allow(menu.menu_items).to receive(:[]).and_return({Beer: 2.0})
You can also pass an specific item if you need:
allow(menu.menu_items).to receive(:[]).with(1).and_return({Beer: 2.0})
The line menu.menu_items[item] is in reality composed by 3 method calls. [] is a call to the method [] on the Hash returned by menu_items.
I assume menu.menu_items returns a Hash and not an Array, given in the spec item is a Symbol.
That means your stub requires a little bit more work.
allow(menu).to receive(:menu_items).and_return({ Beer: 2.0 })
Also note, the error
undefined local variable or method `item'
is because you were using item in the spec, but item is not defined outside your method.
you're going a little too deep with your stub, think of this instead
allow(menu).to receive(:menu_items).and_return({Beer: 2.0})
Thanks to #SimoneCarletti's answer, I was able to easily stub an instance of PublicActivity. I add this answer only as a more brief (re)statement of the OP's problem and the simplicity of the solution.
Code I want to mimic with a stub:
self.entity = activity.parameters['entity_string']
And the salient parts of the test double:
activity = double('activity') # PublicActivity
allow(activity).to receive(:parameters).and_return({'entity_string' => "some entity name"})
Full code:
class ActivityRenderer
attr_accessor :time
attr_accessor :user
attr_accessor :action
attr_accessor :entity
def initialize(activity)
self.entity = activity.parameters['entity_string']
self.time = activity.updated_at
self.user = User.find(activity.owner_id)
self.action = activity.key
end
end
RSpec.describe ActivityRenderer do
let(:user) { ...factory girl stuff... }
let(:now) { Time.zone.now }
before do
Timecop.freeze
end
it 'provides an activity renderer' do
activity = double('activity') # PublicActivity
allow(activity).to receive(:parameters).and_return({'entity_string' => "some entity name"})
allow(activity).to receive(:updated_at).and_return(now)
allow(activity).to receive(:owner_id).and_return(user._id)
allow(activity).to receive(:key).and_return('some activity?')
ar = ActivityRenderer.new(activity)
expect(ar.user).to eql(user)
expect(ar.time).to eql(now)
expect(ar.action).to eql('some activity?')
expect(ar.entity).to eql("some entity name")
end
end
I am writing an ATM-system-like socket/server solution. I would appreciate if someone could tell me what I'm missing. For some reason, I get the following error running my stub test suite:
# Running tests:
.E
Finished tests in 0.002411s, 829.4384 tests/s, 414.7192 assertions/s.
1) Error:
test_0001_connects_to_a_host_with_a_socket(AtmClient::connection):
NoMethodError: undefined method `new' for #<SpoofServer:0x9dce2dc #clients=[], #server=#<TCPServer:fd 5>>
/media/wildfyre/Files/Programming/KTH/progp/Atm/spec/client/SpoofServer.rb:12:in `start'
/media/wildfyre/Files/Programming/KTH/progp/Atm/spec/client/client_spec.rb:12:in `block (3 levels) in <top (required)>'
2 tests, 1 assertions, 0 failures, 1 errors, 0 skips
My minispec file is:
require_relative '../spec_helper.rb'
require_relative '../../lib/AtmClient.rb'
require_relative 'SpoofServer.rb'
describe AtmClient do
it "can be created with no arguments" do
AtmClient.new.must_be_instance_of AtmClient
end
describe 'connection' do
it "connects to a host with a socket" do
spoof = SpoofServer.new.start
client = AtmClient.new.connect
spoof.any_incoming_connection?.must_be true
spoof.kill
end
end
end
My SpoofServer file is:
require 'socket'
class SpoofServer
def initialize
end
def start
#clients = []
#server = TCPServer.new 1234
#listener_thread = new Thread do
#clients.add #server.accept
end
end
def any_incoming_connection?
#clients.size > 0
end
def kill
#listener_thread.exit
#clients.each {|c| c.close}
end
end
As you can read in the trace of the calls stack:
NoMethodError: undefined method `new' for #<SpoofServer:...>
/.../spec/client/SpoofServer.rb:12:in `start'
The error is inside the start method defined in SpoofServer.rb, at line 12, the wrong line is:
#listener_thread = new Thread do
That should be:
#listener_thread = Thread.new do
As you have written it, what you are actually doing is to calling the new method passing the Thread class as argument. Since no new method is defined for instances of the SpoofServer class you get the NoMethodError exception.
In body of instance method SpoofServer#start, you can't call the class method SpoofServer.new by new.
I've got a pretty basic static method on an ActiveRecord model:
#./app/models/comic.rb
class Comic < ActiveRecord::Base
class << self
def furthest
Comic.maximum(:comic_id) || 0
end
end
end
When executing Comic.furthest in the Rails console it returns 0 as I expect. The problem is I am trying to spec this behavior for both the presence and absence of records:
#./spec/app/models/comic_spec.rb
require 'spec_helper'
describe Comic do
describe "#furthest" do
subject { Comic.furthest }
context "when there are no rows in the database" do
it { should == 0 }
end
context "when there are rows in the database" do
before do
Factory.create(:comic, :comic_id => 100)
Factory.create(:comic, :comic_id => 99)
end
it { should == 100 }
end
end
end
All of this appears very basic and straightforward, however my specs are failing with the message:
1) Comic#furthest when there are no rows in the database
Failure/Error: it { should == 0 }
expected: 0
got: nil (using ==)
# ./spec/models/comic_spec.rb:8:in `block (4 levels) in <top (required)>'
Even if I change furthest to simply:
def furthest
0
end
I still get nil (using ==).
The second spec, it { should == 100 } passes with the original Comic.maximum(:comic_id) || 0 definition, as if the Factory.create invocations are required for #furthest to not return nil.
What am I doing wrong?
I am fairly confident this was a problem with me using the p180 release of Ruby 1.9.2 with custom patches to improve require performance. After upgrading to p290 this problem is gone.