2018-03-04 10:09:32 -05:00
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require_relative '../../spec_helper'
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require_relative 'fixtures/classes'
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2017-05-07 08:04:49 -04:00
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describe "Array#at" do
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it "returns the (n+1)'th element for the passed index n" do
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a = [1, 2, 3, 4, 5, 6]
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a.at(0).should == 1
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a.at(1).should == 2
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a.at(5).should == 6
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end
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it "returns nil if the given index is greater than or equal to the array's length" do
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a = [1, 2, 3, 4, 5, 6]
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a.at(6).should == nil
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a.at(7).should == nil
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end
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2017-10-28 11:15:48 -04:00
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it "returns the (-n)'th element from the last, for the given negative index n" do
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2017-05-07 08:04:49 -04:00
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a = [1, 2, 3, 4, 5, 6]
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a.at(-1).should == 6
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a.at(-2).should == 5
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a.at(-6).should == 1
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end
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it "returns nil if the given index is less than -len, where len is length of the array" do
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a = [1, 2, 3, 4, 5, 6]
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a.at(-7).should == nil
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a.at(-8).should == nil
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end
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it "does not extend the array unless the given index is out of range" do
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a = [1, 2, 3, 4, 5, 6]
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a.length.should == 6
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a.at(100)
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a.length.should == 6
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a.at(-100)
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a.length.should == 6
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end
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it "tries to convert the passed argument to an Integer using #to_int" do
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a = ["a", "b", "c"]
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a.at(0.5).should == "a"
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obj = mock('to_int')
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obj.should_receive(:to_int).and_return(2)
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a.at(obj).should == "c"
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end
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it "raises a TypeError when the passed argument can't be coerced to Integer" do
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lambda { [].at("cat") }.should raise_error(TypeError)
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end
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2017-10-28 11:15:48 -04:00
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it "raises an ArgumentError when 2 or more arguments are passed" do
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2017-05-07 08:04:49 -04:00
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lambda { [:a, :b].at(0,1) }.should raise_error(ArgumentError)
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end
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end
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