Ruby. Mocking in RSpec -

i have problem mocking. have class distancematrix , indicate method form_matrix called in if/else statement. need use mocha , rspec. 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 ..."   "should call form_matrix"     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 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 once, not yet invoked: #<anyinstance:distancematrix>.get_data_from_yaml('file_name.yml')      - expected once, not yet invoked: #<anyinstance:distancematrix>.form_matrix([1])      satisfied expectations:      - allowed number of times, invoked once: #<distancematrix:0x9e48b40>.get_optimal_route(any_parameters)      - allowed number of times, 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 in rspec should use not .expects() .should_receive(), tried:

describe distancematrix, "when mocking ..."   "should call form_matrix"     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 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 have experience using mocha , not rspec, looking @ mocha failure message, key parts these :-

unexpected invocation: #<anyinstance:distancematrix>.get_data_from_yaml('file_name.yml', nil) unsatisfied expectations: - expected once, not yet invoked: #<anyinstance:distancematrix>.get_data_from_yaml('file_name.yml') 

if @ ends of these lines, notice get_data_from_yaml not being called expected parameters. being called ('filename.yml', nil) , not ('filename.yml') expected.

this happening because when call distancematrix.new("file_name.yml") in test one argument , inside distancematrix#initialize distancematrix#get_data_from_yaml being called (args[0], args[1]) , since args single element array, args[1] nil.

maybe isn't how expected ruby work, following demonstrates behaviour :-

def foo(*args)   puts "args[0]=#{args[0].inspect}; args[1]=#{args[1].inspect}" end  foo("string") # => args[0]="string"; args[1]=nil