path: root/spec/ruby/core/tracepoint/enable_spec.rb

require_relative '../../spec_helper'
require_relative 'fixtures/classes'

describe 'TracePoint#enable' do
  describe 'without a block' do
    it 'returns false if trace was disabled' do
      called = false
      trace = TracePoint.new(:line) do |tp|
        next unless TracePointSpec.target_thread?
        called = true
      end

      line_event = true
      called.should == false

      ret = trace.enable
      begin
        ret.should == false
        line_event = true
        called.should == true
      ensure
        trace.disable
      end
    end

    it 'returns true if trace was already enabled' do
      called = false
      trace = TracePoint.new(:line) do |tp|
        next unless TracePointSpec.target_thread?
        called = true
      end

      line_event = true
      called.should == false

      ret = trace.enable
      begin
        ret.should == false

        trace.enable.should == true

        line_event = true
        called.should == true
      ensure
        trace.disable
        trace.should_not.enabled?
      end
    end
  end

  describe 'with a block' do
    it 'enables the trace object within a block' do
      event_name = nil
      TracePoint.new(:line) do |tp|
        next unless TracePointSpec.target_thread?
        event_name = tp.event
      end.enable { event_name.should equal(:line) }
    end

    it 'enables the trace object for any thread' do
      threads = []
      trace = TracePoint.new(:line) do |tp|
        # Runs on purpose on any Thread
        threads << Thread.current
      end

      thread = nil
      trace.enable do
        line_event = true
        thread = Thread.new do
          event_in_other_thread = true
        end
        thread.join
      end

      threads = threads.uniq
      threads.should.include?(Thread.current)
      threads.should.include?(thread)
    end

    it 'can accept arguments within a block but it should not yield arguments' do
      event_name = nil
      trace = TracePoint.new(:line) do |tp|
        next unless TracePointSpec.target_thread?
        event_name = tp.event
      end
      trace.enable do |*args|
        event_name.should equal(:line)
        args.should == []
      end
      trace.should_not.enabled?
    end

    it 'enables trace object on calling with a block if it was already enabled' do
      enabled = nil
      trace = TracePoint.new(:line) {}
      trace.enable
      begin
        trace.enable { enabled = trace.enabled? }
        enabled.should == true
      ensure
        trace.disable
      end
    end

    it 'returns the return value of the block' do
      trace = TracePoint.new(:line) {}
      trace.enable { 42 }.should == 42
    end

    it 'disables the trace object outside the block' do
      called = false
      trace = TracePoint.new(:line) do
        next unless TracePointSpec.target_thread?
        called = true
      end
      trace.enable {
        line_event = true
      }
      called.should == true
      trace.should_not.enabled?
    end
  end

  describe "when nested" do
    before do
      ruby_version_is ""..."3.0" do
        @path_prefix = '@'
      end

      ruby_version_is "3.0" do
        @path_prefix = ' '
      end
    end

    it "enables both TracePoints but only calls the respective callbacks" do
      called = false
      first = TracePoint.new(:line) do |tp|
        next unless TracePointSpec.target_thread?
        called = true
      end

      all = []
      inspects = []
      second = TracePoint.new(:line) { |tp|
        next unless TracePointSpec.target_thread?
        all << tp
        inspects << tp.inspect
      }

      line = nil
      first.enable do
        second.enable do
          line = __LINE__
        end
      end

      all.uniq.should == [second]
      inspects.uniq.should == ["#<TracePoint:line#{@path_prefix}#{__FILE__}:#{line}>"]
      called.should == true
    end
  end

  describe 'target: option' do
    before :each do
      ScratchPad.record []
    end

    it 'enables trace point for specific location' do
      trace = TracePoint.new(:call) do |tp|
        next unless TracePointSpec.target_thread?
        ScratchPad << tp.method_id
      end

      obj = Object.new
      def obj.foo; end
      def obj.bar; end

      trace.enable(target: obj.method(:foo)) do
        obj.foo
        obj.bar
      end

      ScratchPad.recorded.should == [:foo]
    end

    it 'traces all the events triggered in specified location' do
      trace = TracePoint.new(:line, :call, :return, :b_call, :b_return) do |tp|
        next unless TracePointSpec.target_thread?
        ScratchPad << tp.event
      end

      obj = Object.new
      def obj.foo
        bar
        -> {}.call
      end
      def obj.bar; end

      trace.enable(target: obj.method(:foo)) do
        obj.foo
      end

      ScratchPad.recorded.uniq.sort.should == [:call, :return, :b_call, :b_return, :line].sort
    end

    it 'does not trace events in nested locations' do
      trace = TracePoint.new(:call) do |tp|
        next unless TracePointSpec.target_thread?
        ScratchPad << tp.method_id
      end

      obj = Object.new
      def obj.foo
        bar
      end
      def obj.bar
        baz
      end
      def obj.baz
      end

      trace.enable(target: obj.method(:foo)) do
        obj.foo
      end

      ScratchPad.recorded.should == [:foo]
    end

    it "traces some events in nested blocks" do
      klass = Class.new do
        def foo
          1.times do
            1.times do
              bar do
              end
            end
          end
        end

        def bar(&blk)
          blk.call
        end
      end

      trace = TracePoint.new(:b_call) do |tp|
        next unless TracePointSpec.target_thread?
        ScratchPad << tp.lineno
      end

      obj = klass.new
      _, lineno = obj.method(:foo).source_location

      trace.enable(target: obj.method(:foo)) do
        obj.foo
      end

      ScratchPad.recorded.should == (lineno+1..lineno+3).to_a
    end

    describe 'option value' do
      it 'accepts Method' do
        trace = TracePoint.new(:call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << tp.method_id
        end

        obj = Object.new
        def obj.foo; end

        trace.enable(target: obj.method(:foo)) do
          obj.foo
        end

        ScratchPad.recorded.should == [:foo]
      end

      it 'accepts UnboundMethod' do
        trace = TracePoint.new(:call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << tp.method_id
        end

        klass = Class.new do
          def foo; end
        end

        unbound_method = klass.instance_method(:foo)
        trace.enable(target: unbound_method) do
          klass.new.foo
        end

        ScratchPad.recorded.should == [:foo]
      end

      it 'accepts Proc' do
        trace = TracePoint.new(:b_call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << tp.lineno
        end

        block = proc {}
        _, lineno = block.source_location

        trace.enable(target: block) do
          block.call
        end

        ScratchPad.recorded.should == [lineno]
        lineno.should be_kind_of(Integer)
      end
    end

    it "raises ArgumentError if target object cannot trigger specified event" do
      trace = TracePoint.new(:call) do |tp|
        next unless TracePointSpec.target_thread?
        ScratchPad << tp.method_id
      end

      block = proc {}

      -> {
        trace.enable(target: block) do
          block.call # triggers :b_call and :b_return events
        end
      }.should raise_error(ArgumentError, /can not enable any hooks/)
    end

    it "raises ArgumentError if passed not Method/UnboundMethod/Proc" do
      trace = TracePoint.new(:call) {}

      -> {
        trace.enable(target: Object.new) do
        end
      }.should raise_error(ArgumentError, /specified target is not supported/)
    end

    context "nested enabling and disabling" do
      it "raises ArgumentError if trace point already enabled with target is re-enabled with target" do
        trace = TracePoint.new(:b_call) {}

        -> {
          trace.enable(target: -> {}) do
            trace.enable(target: -> {}) do
            end
          end
        }.should raise_error(ArgumentError, /can't nest-enable a targett?ing TracePoint/)
      end

      it "raises ArgumentError if trace point already enabled without target is re-enabled with target" do
        trace = TracePoint.new(:b_call) {}

        -> {
          trace.enable do
            trace.enable(target: -> {}) do
            end
          end
        }.should raise_error(ArgumentError, /can't nest-enable a targett?ing TracePoint/)
      end

      it "raises ArgumentError if trace point already enabled with target is re-enabled without target" do
        trace = TracePoint.new(:b_call) {}

        -> {
          trace.enable(target: -> {}) do
            trace.enable do
            end
          end
        }.should raise_error(ArgumentError, /can't nest-enable a targett?ing TracePoint/)
      end

      it "raises ArgumentError if trace point already enabled with target is disabled with block" do
        trace = TracePoint.new(:b_call) {}

        -> {
          trace.enable(target: -> {}) do
            trace.disable do
            end
          end
        }.should raise_error(ArgumentError, /can't disable a targett?ing TracePoint in a block/)
      end

      it "traces events when trace point with target is enabled in another trace point enabled without target" do
        trace_outer = TracePoint.new(:b_call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << :outer
        end

        trace_inner = TracePoint.new(:b_call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << :inner
        end

        target = -> {}

        trace_outer.enable do
          trace_inner.enable(target: target) do
            target.call
          end
        end

        ScratchPad.recorded.should == [:outer, :outer, :outer, :inner]
      end

      it "traces events when trace point with target is enabled in another trace point enabled with target" do
        trace_outer = TracePoint.new(:b_call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << :outer
        end

        trace_inner = TracePoint.new(:b_call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << :inner
        end

        target = -> {}

        trace_outer.enable(target: target) do
          trace_inner.enable(target: target) do
            target.call
          end
        end

        ScratchPad.recorded.should == [:inner, :outer]
      end

      it "traces events when trace point without target is enabled in another trace point enabled with target" do
        trace_outer = TracePoint.new(:b_call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << :outer
        end

        trace_inner = TracePoint.new(:b_call) do |tp|
          next unless TracePointSpec.target_thread?
          ScratchPad << :inner
        end

        target = -> {}

        trace_outer.enable(target: target) do
          trace_inner.enable do
            target.call
          end
        end

        ScratchPad.recorded.should == [:inner, :inner, :outer]
      end
    end
  end

  describe 'target_line: option' do
    before :each do
      ScratchPad.record []
    end

    it "traces :line events only on specified line of code" do
      trace = TracePoint.new(:line) do |tp|
        next unless TracePointSpec.target_thread?
        ScratchPad << tp.lineno
      end

      target = -> {
        x = 1
        y = 2      # <= this line is target
        z = x + y
      }
      _, lineno = target.source_location
      target_line = lineno + 2

      trace.enable(target_line: target_line, target: target) do
        target.call
      end

      ScratchPad.recorded.should == [target_line]
    end

    it "raises ArgumentError if :target option isn't specified" do
      trace = TracePoint.new(:line) {}

      -> {
        trace.enable(target_line: 67) do
        end
      }.should raise_error(ArgumentError, /only target_line is specified/)
    end

    it "raises ArgumentError if :line event isn't registered" do
      trace = TracePoint.new(:call) {}

      target = -> {
        x = 1
        y = 2     # <= this line is target
        z = x + y
      }
      _, lineno = target.source_location
      target_line = lineno + 2

      -> {
        trace.enable(target_line: target_line, target: target) do
        end
      }.should raise_error(ArgumentError, /target_line is specified, but line event is not specified/)
    end

    it "raises ArgumentError if :target_line value is out of target code lines range" do
      trace = TracePoint.new(:line) {}

      -> {
        trace.enable(target_line: 1, target: -> { }) do
        end
      }.should raise_error(ArgumentError, /can not enable any hooks/)
    end

    it "raises TypeError if :target_line value couldn't be coerced to Integer" do
      trace = TracePoint.new(:line) {}

      -> {
        trace.enable(target_line: Object.new, target: -> { }) do
        end
      }.should raise_error(TypeError, /no implicit conversion of \w+? into Integer/)
    end

    it "raises ArgumentError if :target_line value is negative" do
      trace = TracePoint.new(:line) {}

      -> {
        trace.enable(target_line: -2, target: -> { }) do
        end
      }.should raise_error(ArgumentError, /can not enable any hooks/)
    end

    it "accepts value that could be coerced to Integer" do
      trace = TracePoint.new(:line) do |tp|
        next unless TracePointSpec.target_thread?
        ScratchPad << tp.lineno
      end

      target = -> {
        x = 1         #  <= this line is target
      }
      _, lineno = target.source_location
      target_line = lineno + 1

      trace.enable(target_line: target_line.to_r, target: target) do
        target.call
      end

      ScratchPad.recorded.should == [target_line]
    end
  end
end