A spec helper to help you find the origin of all exceptions occurring during your test run (including recovered ones), so you can reduce the abuse of exceptions for control flow. Some surprising facts emerge: a builtin == operator that raises a NoMethodError exception trying to call coerce() on nil... and other wonderful things.

reduce_exceptions_helper.rb

if ENV["RSPEC_REPORT_EXCEPTIONS"]
  class Exception
    alias_method :old_initialize, :initialize

    def self.exceptions_seen
      @@seen ||= {}
    end

    def self.see args
      stack = caller[1..-1]
      # Don't show expected exceptions or RSpec internal ones
      return if caller.detect{|s| s =~ %r{rspec/matchers/raise_error}} or
        self.name =~ /^RSpec::/
      stack.reject!{|s| s =~ %r{/rspec/}}
      key = stack[0,4]+[self.name]
      return if exceptions_seen[key]

      exceptions_seen[key] = show = stack
      args[0] = args[0].to_str if args[0].class.name == "NameError::message"
      puts "#{self.name}#{args.inspect}:\n\t#{show*"\n\t"}"
    end

    def initialize *args, &b
      self.class.see args

      send(:old_initialize, *args, &b)
    end
  end
end