require_relative '../spec_helper' require_relative 'fixtures/break' describe "The break statement in a block" do before :each do ScratchPad.record [] @program = BreakSpecs::Block.new end it "returns nil to method invoking the method yielding to the block when not passed an argument" do @program.break_nil ScratchPad.recorded.should == [:a, :aa, :b, nil, :d] end it "returns a value to the method invoking the method yielding to the block" do @program.break_value ScratchPad.recorded.should == [:a, :aa, :b, :break, :d] end describe "yielded inside a while" do it "breaks out of the block" do value = @program.break_in_block_in_while ScratchPad.recorded.should == [:aa, :break] value.should == :value end end describe "captured and delegated to another method repeatedly" do it "breaks out of the block" do @program.looped_break_in_captured_block ScratchPad.recorded.should == [:begin, :preloop, :predele, :preyield, :prebreak, :postbreak, :postyield, :postdele, :predele, :preyield, :prebreak, :end] end end end describe "The break statement in a captured block" do before :each do ScratchPad.record [] @program = BreakSpecs::Block.new end describe "when the invocation of the scope creating the block is still active" do it "raises a LocalJumpError when invoking the block from the scope creating the block" do -> { @program.break_in_method }.should raise_error(LocalJumpError) ScratchPad.recorded.should == [:a, :xa, :d, :b] end it "raises a LocalJumpError when invoking the block from a method" do -> { @program.break_in_nested_method }.should raise_error(LocalJumpError) ScratchPad.recorded.should == [:a, :xa, :cc, :aa, :b] end it "raises a LocalJumpError when yielding to the block" do -> { @program.break_in_yielding_method }.should raise_error(LocalJumpError) ScratchPad.recorded.should == [:a, :xa, :cc, :aa, :b] end end describe "from a scope that has returned" do it "raises a LocalJumpError when calling the block from a method" do -> { @program.break_in_method_captured }.should raise_error(LocalJumpError) ScratchPad.recorded.should == [:a, :za, :xa, :zd, :zb] end it "raises a LocalJumpError when yielding to the block" do -> { @program.break_in_yield_captured }.should raise_error(LocalJumpError) ScratchPad.recorded.should == [:a, :za, :xa, :zd, :aa, :zb] end end describe "from another thread" do it "raises a LocalJumpError when getting the value from another thread" do thread_with_break = Thread.new do begin break :break rescue LocalJumpError => e e end end thread_with_break.value.should be_an_instance_of(LocalJumpError) end end end describe "The break statement in a lambda" do before :each do ScratchPad.record [] @program = BreakSpecs::Lambda.new end it "returns from the lambda" do l = -> { ScratchPad << :before break :foo ScratchPad << :after } l.call.should == :foo ScratchPad.recorded.should == [:before] end it "returns from the call site if the lambda is passed as a block" do def mid(&b) -> { ScratchPad << :before b.call ScratchPad << :unreachable1 }.call ScratchPad << :unreachable2 end result = [1].each do |e| mid { break # This breaks from mid ScratchPad << :unreachable3 } ScratchPad << :after end result.should == [1] ScratchPad.recorded.should == [:before, :after] end describe "when the invocation of the scope creating the lambda is still active" do it "returns nil when not passed an argument" do @program.break_in_defining_scope false ScratchPad.recorded.should == [:a, :b, nil, :d] end it "returns a value to the scope creating and calling the lambda" do @program.break_in_defining_scope ScratchPad.recorded.should == [:a, :b, :break, :d] end it "returns a value to the method scope below invoking the lambda" do @program.break_in_nested_scope ScratchPad.recorded.should == [:a, :d, :aa, :b, :break, :bb, :e] end it "returns a value to a block scope invoking the lambda in a method below" do @program.break_in_nested_scope_block ScratchPad.recorded.should == [:a, :d, :aa, :aaa, :bb, :b, :break, :cc, :bbb, :dd, :e] end it "returns from the lambda" do @program.break_in_nested_scope_yield ScratchPad.recorded.should == [:a, :d, :aaa, :b, :bbb, :e] end end describe "created at the toplevel" do it "returns a value when invoking from the toplevel" do code = fixture __FILE__, "break_lambda_toplevel.rb" ruby_exe(code).chomp.should == "a,b,break,d" end it "returns a value when invoking from a method" do code = fixture __FILE__, "break_lambda_toplevel_method.rb" ruby_exe(code).chomp.should == "a,d,b,break,e,f" end it "returns a value when invoking from a block" do code = fixture __FILE__, "break_lambda_toplevel_block.rb" ruby_exe(code).chomp.should == "a,d,f,b,break,g,e,h" end end describe "from a scope that has returned" do it "returns a value to the method scope invoking the lambda" do @program.break_in_method ScratchPad.recorded.should == [:a, :la, :ld, :lb, :break, :b] end it "returns a value to the block scope invoking the lambda in a method" do @program.break_in_block_in_method ScratchPad.recorded.should == [:a, :aaa, :b, :la, :ld, :lb, :break, :c, :bbb, :d] end # By passing a lambda as a block argument, the user is requesting to treat # the lambda as a block, which in this case means breaking to a scope that # has returned. This is a subtle and confusing semantic where a block pass # is removing the lambda-ness of a lambda. it "raises a LocalJumpError when yielding to a lambda passed as a block argument" do @program.break_in_method_yield ScratchPad.recorded.should == [:a, :la, :ld, :aaa, :lb, :bbb, :b] end end end describe "Break inside a while loop" do describe "with a value" do it "exits the loop and returns the value" do a = while true; break; end; a.should == nil a = while true; break nil; end; a.should == nil a = while true; break 1; end; a.should == 1 a = while true; break []; end; a.should == [] a = while true; break [1]; end; a.should == [1] end it "passes the value returned by a method with omitted parenthesis and passed block" do obj = BreakSpecs::Block.new -> { break obj.method :value do |x| x end }.call.should == :value end end describe "with a splat" do it "exits the loop and makes the splat an Array" do a = while true; break *[1,2]; end; a.should == [1,2] end it "treats nil as an empty array" do a = while true; break *nil; end; a.should == [] end it "preserves an array as is" do a = while true; break *[]; end; a.should == [] a = while true; break *[1,2]; end; a.should == [1,2] a = while true; break *[nil]; end; a.should == [nil] a = while true; break *[[]]; end; a.should == [[]] end it "wraps a non-Array in an Array" do a = while true; break *1; end; a.should == [1] end end it "stops a while loop when run" do i = 0 while true break if i == 2 i+=1 end i.should == 2 end it "causes a call with a block to return when run" do at = 0 0.upto(5) do |i| at = i break i if i == 2 end.should == 2 at.should == 2 end end # TODO: Rewrite all the specs from here to the end of the file in the style # above. describe "Executing break from within a block" do before :each do ScratchPad.clear end # Discovered in JRuby (see JRUBY-2756) it "returns from the original invoking method even in case of chained calls" do class BreakTest # case #1: yield def self.meth_with_yield(&b) yield fail("break returned from yield to wrong place") end def self.invoking_method(&b) meth_with_yield(&b) fail("break returned from 'meth_with_yield' method to wrong place") end # case #2: block.call def self.meth_with_block_call(&b) b.call fail("break returned from b.call to wrong place") end def self.invoking_method2(&b) meth_with_block_call(&b) fail("break returned from 'meth_with_block_call' method to wrong place") end end # this calls a method that calls another method that yields to the block BreakTest.invoking_method do break fail("break didn't, well, break") end # this calls a method that calls another method that calls the block BreakTest.invoking_method2 do break fail("break didn't, well, break") end res = BreakTest.invoking_method do break :return_value fail("break didn't, well, break") end res.should == :return_value res = BreakTest.invoking_method2 do break :return_value fail("break didn't, well, break") end res.should == :return_value end class BreakTest2 def one two { yield } end def two yield ensure ScratchPad << :two_ensure end def three begin one { break } ScratchPad << :three_post ensure ScratchPad << :three_ensure end end end it "runs ensures when continuing upward" do ScratchPad.record [] bt2 = BreakTest2.new bt2.one { break } ScratchPad.recorded.should == [:two_ensure] end it "runs ensures when breaking from a loop" do ScratchPad.record [] while true begin ScratchPad << :begin break if true ensure ScratchPad << :ensure end end ScratchPad.recorded.should == [:begin, :ensure] end it "doesn't run ensures in the destination method" do ScratchPad.record [] bt2 = BreakTest2.new bt2.three ScratchPad.recorded.should == [:two_ensure, :three_post, :three_ensure] end end