mirror of
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6204e0804b
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66888 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
388 lines
8.7 KiB
Ruby
388 lines
8.7 KiB
Ruby
require_relative '../spec_helper'
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describe "The if expression" do
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ruby_version_is '2.4' do
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describe "accepts multiple assignments in conditional expression" do
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before(:each) { ScratchPad.record([]) }
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after(:each) { ScratchPad.clear }
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it 'with non-nil values' do
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ary = [1, 2]
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eval "if (a, b = ary); ScratchPad.record [a, b]; end"
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ScratchPad.recorded.should == [1, 2]
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end
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it 'with nil values' do
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ary = nil
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eval "if (a, b = ary); else; ScratchPad.record [a, b]; end"
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ScratchPad.recorded.should == [nil, nil]
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end
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end
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end
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it "evaluates body if expression is true" do
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a = []
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if true
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a << 123
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end
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a.should == [123]
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end
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it "does not evaluate body if expression is false" do
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a = []
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if false
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a << 123
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end
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a.should == []
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end
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it "does not evaluate body if expression is empty" do
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a = []
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if ()
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a << 123
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end
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a.should == []
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end
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it "does not evaluate else-body if expression is true" do
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a = []
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if true
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a << 123
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else
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a << 456
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end
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a.should == [123]
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end
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it "evaluates only else-body if expression is false" do
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a = []
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if false
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a << 123
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else
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a << 456
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end
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a.should == [456]
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end
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it "returns result of then-body evaluation if expression is true" do
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if true
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123
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end.should == 123
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end
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it "returns result of last statement in then-body if expression is true" do
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if true
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'foo'
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'bar'
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'baz'
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end.should == 'baz'
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end
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it "returns result of then-body evaluation if expression is true and else part is present" do
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if true
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123
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else
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456
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end.should == 123
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end
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it "returns result of else-body evaluation if expression is false" do
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if false
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123
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else
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456
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end.should == 456
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end
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it "returns nil if then-body is empty and expression is true" do
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if true
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end.should == nil
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end
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it "returns nil if then-body is empty, expression is true and else part is present" do
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if true
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else
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456
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end.should == nil
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end
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it "returns nil if then-body is empty, expression is true and else part is empty" do
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if true
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else
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end.should == nil
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end
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it "returns nil if else-body is empty and expression is false" do
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if false
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123
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else
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end.should == nil
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end
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it "returns nil if else-body is empty, expression is false and then-body is empty" do
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if false
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else
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end.should == nil
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end
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it "considers an expression with nil result as false" do
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if nil
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123
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else
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456
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end.should == 456
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end
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it "considers a non-nil and non-boolean object in expression result as true" do
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if mock('x')
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123
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else
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456
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end.should == 123
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end
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it "considers a zero integer in expression result as true" do
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if 0
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123
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else
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456
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end.should == 123
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end
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it "allows starting else-body on the same line" do
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if false
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123
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else 456
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end.should == 456
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end
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it "evaluates subsequent elsif statements and execute body of first matching" do
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if false
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123
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elsif false
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234
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elsif true
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345
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elsif true
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456
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end.should == 345
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end
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it "evaluates else-body if no if/elsif statements match" do
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if false
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123
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elsif false
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234
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elsif false
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345
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else
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456
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end.should == 456
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end
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it "allows 'then' after expression when then-body is on the next line" do
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if true then
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123
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end.should == 123
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if true then ; 123; end.should == 123
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end
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it "allows then-body on the same line separated with 'then'" do
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if true then 123
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end.should == 123
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if true then 123; end.should == 123
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end
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it "returns nil when then-body on the same line separated with 'then' and expression is false" do
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if false then 123
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end.should == nil
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if false then 123; end.should == nil
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end
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it "returns nil when then-body separated by 'then' is empty and expression is true" do
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if true then
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end.should == nil
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if true then ; end.should == nil
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end
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it "returns nil when then-body separated by 'then', expression is false and no else part" do
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if false then
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end.should == nil
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if false then ; end.should == nil
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end
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it "evaluates then-body when then-body separated by 'then', expression is true and else part is present" do
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if true then 123
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else 456
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end.should == 123
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if true then 123; else 456; end.should == 123
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end
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it "evaluates else-body when then-body separated by 'then' and expression is false" do
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if false then 123
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else 456
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end.should == 456
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if false then 123; else 456; end.should == 456
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end
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describe "with a boolean range ('flip-flop' operator)" do
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before :each do
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ScratchPad.record []
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@verbose = $VERBOSE
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$VERBOSE = nil
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end
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after :each do
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ScratchPad.clear
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$VERBOSE = @verbose
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end
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it "mimics an awk conditional with a single-element inclusive-end range" do
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eval "10.times { |i| ScratchPad << i if (i == 4)..(i == 4) }"
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ScratchPad.recorded.should == [4]
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end
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it "mimics an awk conditional with a many-element inclusive-end range" do
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eval "10.times { |i| ScratchPad << i if (i == 4)..(i == 7) }"
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ScratchPad.recorded.should == [4, 5, 6, 7]
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end
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it "mimics a sed conditional with a zero-element exclusive-end range" do
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eval "10.times { |i| ScratchPad << i if (i == 4)...(i == 4) }"
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ScratchPad.recorded.should == [4, 5, 6, 7, 8, 9]
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end
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it "mimics a sed conditional with a many-element exclusive-end range" do
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eval "10.times { |i| ScratchPad << i if (i == 4)...(i == 5) }"
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ScratchPad.recorded.should == [4, 5]
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end
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it "allows combining two flip-flops" do
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eval "10.times { |i| ScratchPad << i if (i == 4)...(i == 5) or (i == 7)...(i == 8) }"
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ScratchPad.recorded.should == [4, 5, 7, 8]
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end
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it "evaluates the first conditions lazily with inclusive-end range" do
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collector = proc { |i| ScratchPad << i }
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eval "10.times { |i| i if collector[i]...false }"
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ScratchPad.recorded.should == [0]
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end
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it "evaluates the first conditions lazily with exclusive-end range" do
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collector = proc { |i| ScratchPad << i }
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eval "10.times { |i| i if collector[i]..false }"
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ScratchPad.recorded.should == [0]
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end
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it "evaluates the second conditions lazily with inclusive-end range" do
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collector = proc { |i| ScratchPad << i }
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eval "10.times { |i| i if (i == 4)...collector[i] }"
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ScratchPad.recorded.should == [5]
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end
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it "evaluates the second conditions lazily with exclusive-end range" do
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collector = proc { |i| ScratchPad << i }
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eval "10.times { |i| i if (i == 4)..collector[i] }"
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ScratchPad.recorded.should == [4]
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end
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it "scopes state by flip-flop" do
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store_me = eval("proc { |i| ScratchPad << i if (i == 4)..(i == 7) }")
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store_me[1]
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store_me[4]
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proc { store_me[1] }.call
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store_me[7]
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store_me[5]
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ScratchPad.recorded.should == [4, 1, 7]
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end
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it "keeps flip-flops from interfering" do
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a = eval "proc { |i| ScratchPad << i if (i == 4)..(i == 7) }"
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b = eval "proc { |i| ScratchPad << i if (i == 4)..(i == 7) }"
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6.times(&a)
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6.times(&b)
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ScratchPad.recorded.should == [4, 5, 4, 5]
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end
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ruby_version_is "2.6" do
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it 'is deprecated' do
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i = 4
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-> do
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eval "ScratchPad << 'it works' if (i == 4)..(i == 7)"
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end.should complain(/flip-flop is deprecated/)
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ScratchPad.recorded.should == ['it works']
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end
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end
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end
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end
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describe "The postfix if form" do
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it "evaluates statement if expression is true" do
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a = []
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a << 123 if true
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a.should == [123]
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end
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it "does not evaluate statement if expression is false" do
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a = []
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a << 123 if false
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a.should == []
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end
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it "returns result of expression if value is true" do
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(123 if true).should == 123
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end
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it "returns nil if expression is false" do
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(123 if false).should == nil
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end
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it "considers a nil expression as false" do
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(123 if nil).should == nil
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end
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it "considers a non-nil object as true" do
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(123 if mock('x')).should == 123
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end
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it "evaluates then-body in containing scope" do
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a = 123
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if true
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b = a+1
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end
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b.should == 124
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end
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it "evaluates else-body in containing scope" do
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a = 123
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if false
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b = a+1
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else
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b = a+2
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end
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b.should == 125
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end
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it "evaluates elsif-body in containing scope" do
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a = 123
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if false
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b = a+1
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elsif false
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b = a+2
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elsif true
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b = a+3
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else
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b = a+4
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end
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b.should == 126
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end
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end
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