require_relative '../../spec_helper' require_relative 'fixtures/classes' describe "Array#at" do it "returns the (n+1)'th element for the passed index n" do a = [1, 2, 3, 4, 5, 6] a.at(0).should == 1 a.at(1).should == 2 a.at(5).should == 6 end it "returns nil if the given index is greater than or equal to the array's length" do a = [1, 2, 3, 4, 5, 6] a.at(6).should == nil a.at(7).should == nil end it "returns the (-n)'th element from the last, for the given negative index n" do a = [1, 2, 3, 4, 5, 6] a.at(-1).should == 6 a.at(-2).should == 5 a.at(-6).should == 1 end it "returns nil if the given index is less than -len, where len is length of the array" do a = [1, 2, 3, 4, 5, 6] a.at(-7).should == nil a.at(-8).should == nil end it "does not extend the array unless the given index is out of range" do a = [1, 2, 3, 4, 5, 6] a.length.should == 6 a.at(100) a.length.should == 6 a.at(-100) a.length.should == 6 end it "tries to convert the passed argument to an Integer using #to_int" do a = ["a", "b", "c"] a.at(0.5).should == "a" obj = mock('to_int') obj.should_receive(:to_int).and_return(2) a.at(obj).should == "c" end it "raises a TypeError when the passed argument can't be coerced to Integer" do -> { [].at("cat") }.should raise_error(TypeError) end it "raises an ArgumentError when 2 or more arguments are passed" do -> { [:a, :b].at(0,1) }.should raise_error(ArgumentError) end end