Class: RSpec::CallerFilter

Inherits:
Object
  • Object
show all
Defined in:
lib/rspec/expectations/caller_filter.rb

Constant Summary

RSPEC_LIBS = 
%w[
core
mocks
expectations
matchers
rails
ADDITIONAL_TOP_LEVEL_FILES = 
%w[ autorun ]
LIB_REGEX = 
%r{/lib/rspec/(#{(RSPEC_LIBS + ADDITIONAL_TOP_LEVEL_FILES).join('|')})(\.rb|/)}

Class Method Summary (collapse)

Class Method Details

+ (Object) first_non_rspec_line

Earlier rubies do not support the two argument form of caller. This fallback is logically the same, but slower.

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# File 'lib/rspec/expectations/caller_filter.rb', line 53
def self.first_non_rspec_line
  # `caller` is an expensive method that scales linearly with the size of
  # the stack. The performance hit for fetching it in chunks is small,
  # and since the target line is probably near the top of the stack, the
  # overall improvement of a chunked search like this is significant.
  #
  # See benchmarks/caller.rb for measurements.

  # Initial value here is mostly arbitrary, but is chosen to give good
  # performance on the common case of creating a double.
  increment = 5
  i         = 1
  line      = nil
  while !line
    stack = caller(i, increment)
    return nil unless stack
    line = stack.find { |l| l !~ LIB_REGEX }
    i         += increment
    increment *= 2 # The choice of two here is arbitrary.
  end
  line
end