require_relative '../../spec_helper' require_relative 'fixtures/classes' describe "Array#transpose" do it "assumes an array of arrays and returns the result of transposing rows and columns" do [[1, 'a'], [2, 'b'], [3, 'c']].transpose.should == [[1, 2, 3], ["a", "b", "c"]] [[1, 2, 3], ["a", "b", "c"]].transpose.should == [[1, 'a'], [2, 'b'], [3, 'c']] [].transpose.should == [] [[]].transpose.should == [] [[], []].transpose.should == [] [[0]].transpose.should == [[0]] [[0], [1]].transpose.should == [[0, 1]] end it "tries to convert the passed argument to an Array using #to_ary" do obj = mock('[1,2]') obj.should_receive(:to_ary).and_return([1, 2]) [obj, [:a, :b]].transpose.should == [[1, :a], [2, :b]] end it "properly handles recursive arrays" do empty = ArraySpecs.empty_recursive_array empty.transpose.should == empty a = []; a << a b = []; b << b [a, b].transpose.should == [[a, b]] a = [1]; a << a b = [2]; b << b [a, b].transpose.should == [ [1, 2], [a, b] ] end it "raises a TypeError if the passed Argument does not respond to #to_ary" do lambda { [Object.new, [:a, :b]].transpose }.should raise_error(TypeError) end it "does not call to_ary on array subclass elements" do ary = [ArraySpecs::ToAryArray[1, 2], ArraySpecs::ToAryArray[4, 6]] ary.transpose.should == [[1, 4], [2, 6]] end it "raises an IndexError if the arrays are not of the same length" do lambda { [[1, 2], [:a]].transpose }.should raise_error(IndexError) end it "does not return subclass instance on Array subclasses" do result = ArraySpecs::MyArray[ArraySpecs::MyArray[1, 2, 3], ArraySpecs::MyArray[4, 5, 6]].transpose result.should be_an_instance_of(Array) result[0].should be_an_instance_of(Array) result[1].should be_an_instance_of(Array) end end