File with object under test: foo.rb
class Foo
def a_string
"abcdef8"
end
end
Spec file: foo_spec.rb
require_relative "./foo"
describe Foo do
let(:foo) {Foo.new}
let(:my_matcher) {/^[a-z]+(\d)$/}
# This test passes
it "should match and pass" do
my_str = foo.a_string
my_matcher # <--- why does this affect the test?
matcher = my_str.match(my_matcher)
8.should == matcher[1].to_i
end
# This test fails
it "should also match and pass but fails" do
my_str = foo.a_string
#my_matcher #<---- the only change between the tests
matcher = my_str.match(my_matcher) #<---- when called here, it behaves differently
8.should == matcher[1].to_i
end
end
rspec foo_spec.rb
.F
Failures:
1) Foo should also match and pass but fails
Failure/Error: 8.should == matcher[1].to_i
NoMethodError:
undefined method `[]' for /^[a-z]+(\d)$/:Regexp
# ./foo_spec.rb:18:in `block (2 levels) in <top (required)>'
Finished in 0.00095 seconds
2 examples, 1 failure
Failed examples:
rspec ./foo_spec.rb:14 # Foo should also match and pass but fails
The only difference in the two tests is whether my_matcher is invoked. I first noticed this problem when I was inspecting my_matcher (i.e. p my_matcher), but it also occurs with just invoking my_matcher.
Is this a bug, or am I doing something wrong? Maybe it has something to do with capturing Regex data?
It seems incredibly odd behavior, especially for ruby.
For what its worth, it's an easy (if slightly less DRY) fix. If my_matcher is declared in the it block it works as expected.
That looks like a bug. Can you file an issue with rspec-core?
Related
I'm trying to teach myself Ruby. I don't know anyone who knows it, so I don't have anyone to help with my very simple, perhaps annoying problems. I'm running the following code and getting the following error:
def simon_says (command)
def echo (param)
puts "#{param}"
end
end
The error:
PS R:\learn_ruby\03_simon_says> rake
(in R:/learn_ruby)
You must use ANSICON 1.31 or later (http://adoxa.3eeweb.com/ansicon/) to use colour on Windows
Simon says
echo
should echo hello (FAILED - 1)
Failures:
1) Simon says echo should echo hello
Failure/Error: echo("hello").should == "hello"
NoMethodError:
undefined method `echo' for #RSpec::Core::ExampleGroup::Nested_1::Nested_1:0x2fb5690>
# ./03_simon_says/simon_says_spec.rb:19:in `block (3 levels) in <top (required)>'
Finished in 0.003 seconds
1 example, 1 failure
The Rspec code can be found here (Github): simon_says_spec.rb
I just really have no idea what's wrong. Why would it say 'echo' is undefined? It looks defined to me. I also tried just outputting "hello" itself instead of the method parameter (param). Same error. All help appreciated. Also, if anyone knows of a more level appropriate place I can get this kind of help, it'd be nice.
Your program says the following:
Define a method called simon_says. When that function is executed, it should define a method called echo.
Thus, before you invoke simon_says(), echo does not exist:
echo("foo")
# NoMethodError
simon_says("whatever")
# => nil
echo("bar")
# bar
# => nil
Now, I do not know why you wrapped def echo inside def simon_says, so I can't really offer any helpful advice as to what you should be doing instead of what you now are.
Looking to your spec, I guess simon_says is class. It is not method. You are defining method inside method. Try this
class SimonSays
def echo params
puts "#{params}"
end
end
This is very weird. The following code:
describe "Spike" do
before(:all) do
something = double('name')
end
describe "a test" do
it "is basic" do
1.should == 1
end
end
end
Fails with:
NoMethodError: undefined method `double' for #<RSpec::Core::ExampleGroup::Nested_1:0x9dec5e8 #__memoized=nil>
./spec/unit/whatever/spike_spec.rb:3:in `block (2 levels) in '
Change the before(:all) to before(:each) and everything is fine. I'm using Ruby 1.9.3
Any ideas?
This is expected behavior, since doubles get cleaned out after every example. You should stick with using these in a before(:each) block.
See https://www.relishapp.com/rspec/rspec-mocks/docs/scope
Also see https://github.com/rspec/rspec-core/issues/202 for discussion on this.
Here is the class that I'm testing contained in Foo.rb:
class Foo
def bar
return 2
end
end
Here is the my test contained in Foo_spec.rb:
require "./Foo.rb"
describe "Foo" do
before(:all) do
puts "#{Foo == nil}"
Foo.any_instance.stub(:bar).and_return(1)
end
it "should pass this" do
f = Foo.new
f.bar.should eq 1
end
end
I am getting the following output:
false
F
Failures:
1) Foo Should pass this
Failure/Error: Foo.any_instance.stub(:bar).and_return(1)
NoMethodError:
undefined method `any_instance_recorder_for' for nil:NilClass
# ./Foo_spec.rb:6:in `block (2 levels) in <top (required)>'
Finished in 0 seconds
1 example, 1 failure
Failed examples:
rspec ./Foo_spec.rb:9 # Foo Should pass this
I've consulted the doc and the example given is passing on my machine (so it isn't a problem with the rspec code), but it isn't giving me any information on what I might be doing wrong. The error message is also quite confusing as it's telling me not to call .any_instance on a nil:NilClass, but as I proved with my output, Foo isn't nil. How am I supposed to call .any_instance.stub on my custom object?
I'm using Ruby 1.9.3 and rspec 2.14.5.
You should use before(:each) for stubbing.
Stubs in before(:all) are not supported. The reason is that all stubs and mocks get cleared out after each example, so any stub that is set in before(:all) would work in the first example that happens to run in that group, but not for any others.
rspec-mocks readme
From Rspec 3 any_instance is not defined anymore.
Now use:
allow_any_instance_of(Foo).to receive(:bar).and_return(1)
Source for this and older versions:
https://makandracards.com/makandra/2561-stub-methods-on-any-instance-of-a-class-in-rspec-1-and-rspec-2
Updating rspec worked for me. You can do it using the following command:
bundle update rspec
I want to write some tree data structure in ruby. The class file:
class Tree
attr_accessor :node, :left, :right
def initialize(node, left=nil, right=nil)
self.node=node
self.left=left
self.right=right
end
end
The rspec file:
require 'init.rb'
describe Tree do
it "should be created" do
t2=Tree.new(2)
t1=Tree.new(1)
t=Tree.new(3,t1,t2)
t.should_not be nil
t.left.node should eql 1
t.right.node should eql 2
end
end
Rspec keeps complaining:
1) Tree should be created
Failure/Error: t.left.node should eql 1
ArgumentError:
wrong number of arguments (0 for 1)
# ./app/tree.rb:3:in `initialize'
# ./spec/tree_spec.rb:9:in `block (2 levels) in <top (required)>'
Why?? I move the spec code into the class file and it works out. What is wrong?
Believe it or not, the problem is two missing dots in your rspec. These lines:
t.left.node should eql 1
t.right.node should eql 2
should be this:
t.left.node.should eql 1
t.right.node.should eql 2
Insert that period before should, and your spec should pass.
Here's what's going on. The should method works on any value, but if you call it bare, like this:
should == "hello"
it will operate on the subject of your test. What's the subject? Well, you can set the subject to whatever you want using the subject method, but if you don't, rspec will assume the subject is an instance of whatever class is being described. It sees this at the top of your spec:
describe Tree
and tries to create a subject like this:
Tree.new
which blows up, since your initialize won't work without any arguments; it needs at least one. The result is a pretty cryptic error if you didn't intend to write a should with an implicit subject.
I have a problem with mocking. I have class DistanceMatrix and I would
like to indicate which method form_matrix was called in if/else
statement. I need to use mocha and RSpec. Any ideas?
class DistanceMatrix
def initialize(*args)
if args[0].class == String
form_matrix(get_data_from_yaml(args[0], args[1]))
elsif args[0].class == Array || args[0] == nil
form_matrix(get_data_from_db(args[0]))
end
end
def form_matrix(...)
...
end
end
it tried:
describe DistanceMatrix, "when mocking ..." do
it "should do call form_matrix" do
DistanceMatrix.any_instance.expects(:form_matrix).with([1]).once
DistanceMatrix.any_instance.expects(:get_data_from_yaml).with("file_name.yml").once.returns([1])
DistanceMatrix.new("file_name.yml")
end
end
but got error:
Failures:
1) DistanceMatrix when mocking ... should do call form_matrix
Failure/Error: DistanceMatrix.new("file_name.yml")
unexpected invocation: #<AnyInstance:DistanceMatrix>.get_data_from_yaml('file_name.yml', nil)
unsatisfied expectations:
- expected exactly once, not yet invoked: #<AnyInstance:DistanceMatrix>.get_data_from_yaml('file_name.yml')
- expected exactly once, not yet invoked: #<AnyInstance:DistanceMatrix>.form_matrix([1])
satisfied expectations:
- allowed any number of times, already invoked once: #<DistanceMatrix:0x9e48b40>.get_optimal_route(any_parameters)
- allowed any number of times, already invoked once: #<Database::Distances:0x9d59798>.load_distances(any_parameters)
# ./distance_matrix.rb:18:in `initialize'
# ./tsp_algorithm_spec.rb:253:in `new'
# ./tsp_algorithm_spec.rb:253:in `block (2 levels) in <top (required)>'
Finished in 0.25979 seconds
I found that in RSpec we should use not .expects() but .should_receive(), so I tried:
describe DistanceMatrix, "when mocking ..." do
it "should do call form_matrix" do
DistanceMatrix.any_instance.should_receive(:form_matrix).with([1])
DistanceMatrix.any_instance.should_receive(:get_data_from_yaml).with("file_name.yml").and_return([1])
DistanceMatrix.new("file_name.yml")
end
end
but got new failure:
Failures:
1) DistanceMatrix when mocking ... should do call form_matrix
Failure/Error: DistanceMatrix.any_instance.should_receive(:form_matrix).with([1])
(#<Mocha::ClassMethods::AnyInstance:0x96356b0>).form_matrix([1])
expected: 1 time
received: 0 times
# ./tsp_algorithm_spec.rb:251:in `block (2 levels) in <top (required)>'
Finished in 0.26741 seconds
I only have experience with using Mocha and not RSpec, but looking at the Mocha failure message, the key parts are these :-
unexpected invocation: #<AnyInstance:DistanceMatrix>.get_data_from_yaml('file_name.yml', nil)
unsatisfied expectations:
- expected exactly once, not yet invoked: #<AnyInstance:DistanceMatrix>.get_data_from_yaml('file_name.yml')
If you look at the ends of these lines, you will notice that get_data_from_yaml is not being called with the expected parameters. It is being called with ('filename.yml', nil) and not ('filename.yml') as expected.
This is happening because when you call DistanceMatrix.new("file_name.yml") in your test with only one argument and then inside DistanceMatrix#initialize DistanceMatrix#get_data_from_yaml is being called with (args[0], args[1]) and since args is a single element array, args[1] will be nil.
Maybe this isn't how you expected Ruby to work, but the following demonstrates this behaviour :-
def foo(*args)
puts "args[0]=#{args[0].inspect}; args[1]=#{args[1].inspect}"
end
foo("string") # => args[0]="string"; args[1]=nil
DistanceMatrix.any_instance.expects(:form_matrix).with("String") # => supply the correct string param
or
DistanceMatrix.any_instance.expects(:form_matrix).with([]) # => supply the correct array param
I'm not sure what your get_data_from_db and get_data_from_yaml methods are doing, but you should be able to control those inputs as well to verify the correct arguments are being supplied to form_matrix.
EDITED
You'll have to use DistanceMatrix.any_instance instead of mocking on an instance variable because you're trying to mock something in the initializer. Also, in case its unclear, you'll need to actually make the appropriate method call after you set up the mock in the lines above, e.g.
DistanceMatrix.new("SomeString")
EDITED
it "should do call #form_matrix with proper arguments" do
DistanceMatrix.any_instance.expects(:form_matrix).with([1])
DistanceMatrix.any_instance.expects(:get_data_from_yaml).with("foo").returns([1])
DistanceMatrix.new("foo")
end