RSpec: expect array of hashes in class_double recieve - ruby-on-rails-4

Question

I want to test with RSpec a function my_test. The function calls another class's class method MyHelper.func in rails 4.
I used mock to illustrate func in class MyHelper, and I want to match the argument that func receives with some const values.
I used
expect(<double>).to receive(func).with(arguments)
But one of the const arguments is a hash with more than 2 items. When I test my
function, RSpec throws an error:
received :func with unexpected arguments.
expected: [{"1"=>33.33},{"2"=>33.33},{"3"=>33.33}]
got: [{"2"=>33.33},{"1"=>33.33},{"3"=>33.33}]
Is there a way to match between the two arrays?
The code:
my_hash = [{"1"=>33.33},{"2"=>33.33},{"3"=>33.33}]
notifier = class_double("MyHelper").
as_stubbed_const(:transfer_nested_constant => true)
expect(notifier).to receive(:func).with(my_hash)

Answer 1

This is a bit tricky since you are comparing two things that are not equal when using ==
let(:expected) { [{"1"=>33.33},{"2"=>33.33},{"3"=>33.33}] }
let(:actual) { [{"2"=>33.33},{"1"=>33.33},{"3"=>33.33}] }
expect(actual).to eq(expected) # fails
However, you can define a custom matcher and use it to compare the arguments:
RSpec::Matchers.define :sorted_array_match do |expected|
match do |actual|
expected_hash = expected.inject({}) {|m,(k,v)| m.merge!(k=>v)}
actual_hash = actual.inject({}) {|m,(k,v)| m.merge!(k=>v)}
actual_hash == expected_hash
end
end
it "should work" do
expect(notifier).to receive(:func).with(sorted_array_match(expected))
notifier.func(actual)
end
Note that this converts the array argument into a hash, so it assumes the arguments are arrays containing hashes with different keys. You might need to alter it to fit the actual data.
More info in the RSpec docs.