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require 'spec_helper'
describe Immutable::List do
describe '#one?' do
context 'on a really big list' do
it "doesn't run out of stack" do
-> { BigList.one? { false } }.should_not raise_error
end
end
context 'when empty' do
it 'with a block returns false' do
L.empty.one? {}.should == false
end
it 'with no block returns false' do
L.empty.one?.should == false
end
end
context 'when not empty' do
context 'with a block' do
let(:list) { L['A', 'B', 'C'] }
it 'returns false if the block returns true more than once' do
list.one? { |item| true }.should == false
end
it 'returns false if the block never returns true' do
list.one? { |item| false }.should == false
end
it 'returns true if the block only returns true once' do
list.one? { |item| item == 'A' }.should == true
end
end
context 'with no block' do
it 'returns false if more than one value is truthy' do
L[nil, true, 'A'].one?.should == false
end
it 'returns true if only one value is truthy' do
L[nil, true, false].one?.should == true
end
end
end
end
end
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