spec/ruby/core/thread/backtrace_locations_spec.rb

   1 require_relative '../../spec_helper'
   2
   3 describe "Thread#backtrace_locations" do
   4   it "returns an Array" do
   5     locations = Thread.current.backtrace_locations
   6     locations.should be_an_instance_of(Array)
   7     locations.should_not be_empty
   8   end
   9
  10   it "sets each element to a Thread::Backtrace::Location" do
  11     locations = Thread.current.backtrace_locations
  12     locations.each { |loc| loc.should be_an_instance_of(Thread::Backtrace::Location) }
  13   end
  14
  15   it "can be called on any Thread" do
  16     locations = Thread.new { Thread.current.backtrace_locations }.value
  17     locations.should be_an_instance_of(Array)
  18     locations.should_not be_empty
  19     locations.each { |loc| loc.should be_an_instance_of(Thread::Backtrace::Location) }
  20   end
  21
  22   it "can be called with a number of locations to omit" do
  23     locations1 = Thread.current.backtrace_locations
  24     locations2 = Thread.current.backtrace_locations(2)
  25     locations2.length.should == locations1[2..-1].length
  26     locations2.map(&:to_s).should == locations1[2..-1].map(&:to_s)
  27   end
  28
  29   it "can be called with a maximum number of locations to return as second parameter" do
  30     locations1 = Thread.current.backtrace_locations
  31     locations2 = Thread.current.backtrace_locations(2, 3)
  32     locations2.map(&:to_s).should == locations1[2..4].map(&:to_s)
  33   end
  34
  35   it "can be called with a range" do
  36     locations1 = Thread.current.backtrace_locations
  37     locations2 = Thread.current.backtrace_locations(2..4)
  38     locations2.map(&:to_s).should == locations1[2..4].map(&:to_s)
  39   end
  40
  41   it "can be called with a range whose end is negative" do
  42     Thread.current.backtrace_locations(2..-1).map(&:to_s).should == Thread.current.backtrace_locations[2..-1].map(&:to_s)
  43     Thread.current.backtrace_locations(2..-2).map(&:to_s).should == Thread.current.backtrace_locations[2..-2].map(&:to_s)
  44   end
  45
  46   it "can be called with an endless range" do
  47     locations1 = Thread.current.backtrace_locations(0)
  48     locations2 = Thread.current.backtrace_locations(eval("(2..)"))
  49     locations2.map(&:to_s).should == locations1[2..-1].map(&:to_s)
  50   end
  51
  52   it "can be called with an beginless range" do
  53     locations1 = Thread.current.backtrace_locations(0)
  54     locations2 = Thread.current.backtrace_locations((..5))
  55     locations2.map(&:to_s)[eval("(2..)")].should == locations1[(..5)].map(&:to_s)[eval("(2..)")]
  56   end
  57
  58   it "returns nil if omitting more locations than available" do
  59     Thread.current.backtrace_locations(100).should == nil
  60     Thread.current.backtrace_locations(100..-1).should == nil
  61   end
  62
  63   it "returns [] if omitting exactly the number of locations available" do
  64     omit = Thread.current.backtrace_locations.length
  65     Thread.current.backtrace_locations(omit).should == []
  66   end
  67
  68   it "without argument is the same as showing all locations with 0..-1" do
  69     Thread.current.backtrace_locations.map(&:to_s).should == Thread.current.backtrace_locations(0..-1).map(&:to_s)
  70   end
  71
  72   it "the first location reports the call to #backtrace_locations" do
  73     Thread.current.backtrace_locations(0..0)[0].to_s.should =~ /\A#{__FILE__ }:#{__LINE__ }:in [`'](?:Thread#)?backtrace_locations'\z/
  74   end
  75
  76   it "[1..-1] is the same as #caller_locations(0..-1) for Thread.current" do
  77     Thread.current.backtrace_locations(1..-1).map(&:to_s).should == caller_locations(0..-1).map(&:to_s)
  78   end
  79 end