path: root/spec/ruby/language/return_spec.rb

require File.expand_path('../../spec_helper', __FILE__)
require File.expand_path('../fixtures/return', __FILE__)

describe "The return keyword" do
  it "returns any object directly" do
    def r; return 1; end
    r().should == 1
  end

  it "returns an single element array directly" do
    def r; return [1]; end
    r().should == [1]
  end

  it "returns an multi element array directly" do
    def r; return [1,2]; end
    r().should == [1,2]
  end

  it "returns nil by default" do
    def r; return; end
    r().should be_nil
  end

  describe "in a Thread" do
    it "raises a LocalJumpError if used to exit a thread" do
      t = Thread.new {
        begin
          return
        rescue LocalJumpError => e
          e
        end
      }
      t.value.should be_an_instance_of(LocalJumpError)
    end
  end

  describe "when passed a splat" do
    it "returns [] when the ary is empty" do
      def r; ary = []; return *ary; end
      r.should == []
    end

    it "returns the array when the array is size of 1" do
      def r; ary = [1]; return *ary; end
      r.should == [1]
    end

    it "returns the whole array when size is greater than 1" do
      def r; ary = [1,2]; return *ary; end
      r.should == [1,2]

      def r; ary = [1,2,3]; return *ary; end
      r.should == [1,2,3]
    end

    it "returns an array when used as a splat" do
      def r; value = 1; return *value; end
      r.should == [1]
    end

    it "calls 'to_a' on the splatted value first" do
      def r
        obj = Object.new
        def obj.to_a
          [1,2]
        end

        return *obj
      end

      r().should == [1,2]
    end
  end

  describe "within a begin" do
    before :each do
      ScratchPad.record []
    end

    it "executes ensure before returning" do
      def f()
        begin
          ScratchPad << :begin
          return :begin
          ScratchPad << :after_begin
        ensure
          ScratchPad << :ensure
        end
        ScratchPad << :function
      end
      f().should == :begin
      ScratchPad.recorded.should == [:begin, :ensure]
    end

    it "returns last value returned in ensure" do
      def f()
        begin
          ScratchPad << :begin
          return :begin
          ScratchPad << :after_begin
        ensure
          ScratchPad << :ensure
          return :ensure
          ScratchPad << :after_ensure
        end
        ScratchPad << :function
      end
      f().should == :ensure
      ScratchPad.recorded.should == [:begin, :ensure]
    end

    it "executes nested ensures before returning" do
      def f()
        begin
          begin
            ScratchPad << :inner_begin
            return :inner_begin
            ScratchPad << :after_inner_begin
          ensure
            ScratchPad << :inner_ensure
          end
          ScratchPad << :outer_begin
          return :outer_begin
          ScratchPad << :after_outer_begin
        ensure
          ScratchPad << :outer_ensure
        end
        ScratchPad << :function
      end
      f().should == :inner_begin
      ScratchPad.recorded.should == [:inner_begin, :inner_ensure, :outer_ensure]
    end

    it "returns last value returned in nested ensures" do
      def f()
        begin
          begin
            ScratchPad << :inner_begin
            return :inner_begin
            ScratchPad << :after_inner_begin
          ensure
            ScratchPad << :inner_ensure
            return :inner_ensure
            ScratchPad << :after_inner_ensure
          end
          ScratchPad << :outer_begin
          return :outer_begin
          ScratchPad << :after_outer_begin
        ensure
          ScratchPad << :outer_ensure
          return :outer_ensure
          ScratchPad << :after_outer_ensure
        end
        ScratchPad << :function
      end
      f().should == :outer_ensure
      ScratchPad.recorded.should == [:inner_begin, :inner_ensure, :outer_ensure]
    end

    it "executes the ensure clause when begin/ensure are inside a lambda" do
      lambda do
        begin
          return
        ensure
          ScratchPad.recorded << :ensure
        end
      end.call
      ScratchPad.recorded.should == [:ensure]
    end
  end

  describe "within a block" do
    before :each do
      ScratchPad.clear
    end

    it "causes lambda to return nil if invoked without any arguments" do
      lambda { return; 456 }.call.should be_nil
    end

    it "causes lambda to return nil if invoked with an empty expression" do
      lambda { return (); 456 }.call.should be_nil
    end

    it "causes lambda to return the value passed to return" do
      lambda { return 123; 456 }.call.should == 123
    end

    it "causes the method that lexically encloses the block to return" do
      ReturnSpecs::Blocks.new.enclosing_method.should == :return_value
      ScratchPad.recorded.should == :before_return
    end

    it "returns from the lexically enclosing method even in case of chained calls" do
      ReturnSpecs::NestedCalls.new.enclosing_method.should == :return_value
      ScratchPad.recorded.should == :before_return
    end

    it "returns from the lexically enclosing method even in case of chained calls(in yield)" do
      ReturnSpecs::NestedBlocks.new.enclosing_method.should == :return_value
      ScratchPad.recorded.should == :before_return
    end

    it "causes the method to return even when the immediate parent has already returned" do
      ReturnSpecs::SavedInnerBlock.new.start.should == :return_value
      ScratchPad.recorded.should == :before_return
    end

    # jruby/jruby#3143
    describe "downstream from a lambda" do
      it "returns to its own return-capturing lexical enclosure" do
        def a
          ->{ yield }.call
          return 2
        end
        def b
          a { return 1 }
        end

        b.should == 1
      end
    end

  end

  describe "within two blocks" do
    it "causes the method that lexically encloses the block to return" do
      def f
        1.times { 1.times {return true}; false}; false
      end
      f.should be_true
    end
  end

  describe "within define_method" do
    it "goes through the method via a closure" do
      ReturnSpecs::ThroughDefineMethod.new.outer.should == :good
    end

    it "stops at the method when the return is used directly" do
      ReturnSpecs::DefineMethod.new.outer.should == :good
    end
  end

  describe "invoked with a method call without parentheses with a block" do
    it "returns the value returned from the method call" do
      ReturnSpecs::MethodWithBlock.new.method1.should == 5
      ReturnSpecs::MethodWithBlock.new.method2.should == [0, 1, 2]
    end
  end

  ruby_version_is '2.4.2' do
    describe "at top level" do
      before :each do
        @filename = tmp("top_return.rb")
        ScratchPad.record []
      end

      after do
        rm_r @filename
      end

      it "stops file execution" do
        ruby_exe(<<-END_OF_CODE).should == "before return\n"
          puts "before return"
          return

          puts "after return"
        END_OF_CODE

        $?.exitstatus.should == 0
      end

      describe "within if" do
        it "is allowed" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before if"
            if true
              return
            end

            ScratchPad << "after if"
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before if"]
        end
      end

      describe "within while loop" do
        it "is allowed" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before while"
            while true
              return
            end

            ScratchPad << "after while"
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before while"]
        end
      end

      describe "within a begin" do
        it "is allowed in begin block" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before begin"
            begin
              return
            end

            ScratchPad << "after begin"
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before begin"]
        end

        it "is allowed in ensure block" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before begin"
            begin
            ensure
              return
            end

            ScratchPad << "after begin"
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before begin"]
        end

        it "is allowed in rescue block" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before begin"
            begin
              raise
            rescue RuntimeError
              return
            end

            ScratchPad << "after begin"
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before begin"]
        end

        it "fires ensure block before returning" do
          ruby_exe(<<-END_OF_CODE).should == "within ensure\n"
            begin
              return
            ensure
              puts "within ensure"
            end

            puts "after begin"
          END_OF_CODE
        end

        ruby_bug "#14061", "2.4"..."2.6" do
          it "fires ensure block before returning while loads file" do
            File.write(@filename, <<-END_OF_CODE)
              ScratchPad << "before begin"
              begin
                return
              ensure
                ScratchPad << "within ensure"
              end

              ScratchPad << "after begin"
            END_OF_CODE

            load @filename
            ScratchPad.recorded.should == ["before begin", "within ensure"]
          end
        end

        it "swallows exception if returns in ensure block" do
          File.write(@filename, <<-END_OF_CODE)
            begin
              raise
            ensure
              ScratchPad << "before return"
              return
            end
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before return"]
        end
      end

      describe "within a block" do
        it "is allowed" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before call"
            proc { return }.call

            ScratchPad << "after call"
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before call"]
        end
      end

      describe "file loading" do
        it "stops file loading and execution" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before return"
            return
            ScratchPad << "after return"
          END_OF_CODE

          load @filename
          ScratchPad.recorded.should == ["before return"]
        end
      end

      describe "file requiring" do
        it "stops file loading and execution" do
          File.write(@filename, <<-END_OF_CODE)
            ScratchPad << "before return"
            return
            ScratchPad << "after return"
          END_OF_CODE

          require @filename
          ScratchPad.recorded.should == ["before return"]
        end
      end

      describe "return with argument" do
        # https://bugs.ruby-lang.org/issues/14062
        it "does not affect exit status" do
          ruby_exe(<<-END_OF_CODE).should == ""
            return 10
          END_OF_CODE

          $?.exitstatus.should == 0
        end
      end
    end
  end
end