Module: Mocktail::Debug

Extended by:
T::Sig
Defined in:
lib/mocktail/debug.rb,
lib/mocktail/sorbet/mocktail/debug.rb

Class Method Summary collapse

Class Method Details

.guard_against_mocktail_accidentally_calling_mocks_if_debugging! ⇒ Object

It would be easy and bad for the mocktail lib to call something like

double == other_double

But if it’s a double, that means anyone who stubs that method could change the internal behavior of the library in unexpected ways (as happened here: github.com/testdouble/mocktail/issues/7 )

For that reason when we run our tests, we also want to blow up if this happens unintentionally. This works in conjunction with the test MockingMethodfulClassesTest, because it mocks every defined method on the mocked BasicObject



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# File 'lib/mocktail/debug.rb', line 18

def self.guard_against_mocktail_accidentally_calling_mocks_if_debugging!
  return unless ENV["MOCKTAIL_DEBUG_ACCIDENTAL_INTERNAL_MOCK_CALLS"]
  raise Mocktail::Error
rescue Mocktail::Error => e
  base_path = Pathname.new(__FILE__).dirname.to_s
  backtrace_minus_this_and_whoever_called_this = e.backtrace&.[](2..)
  internal_call_sites = backtrace_minus_this_and_whoever_called_this&.take_while { |call_site|
    # the "in `block" is very confusing but necessary to include lines after
    # a stubs { blah.foo }.with { … } call, since that's when most of the
    # good stuff happens
    call_site.start_with?(base_path) || call_site.include?("in `block")
  }&.reject { |call_site| call_site.include?("in `block") } || []

  approved_call_sites = [
    /fulfills_stubbing.rb:(16|20)/,
    /validates_arguments.rb:(18|23)/,
    /validates_arguments.rb:(21|26)/
  ]
  if internal_call_sites.any? && approved_call_sites.none? { |approved_call_site|
    internal_call_sites.first&.match?(approved_call_site)
  }
    raise Error.new <<~MSG
      Unauthorized internal call of a mock internally by Mocktail itself:

      #{internal_call_sites.first}

      Offending call's complete stack trace:

      #{backtrace_minus_this_and_whoever_called_this&.join("\n")}
      ==END OFFENDING TRACE==
    MSG
  end
end