rspec-rails 3.5.1 + rails 5, running whole spec suite results in (seemingly) random LoadErrors

[grandconjuration]

$ ruby -v
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-darwin15]
$ rails -v
Rails 5.0.0
$ rspec -v
3.5.1

We're migrating from Rails 4 to Rails 5 and we're having a problem when running the whole spec suite.
When I run rspec using the rspec (without arguments) command I randomly get
LoadError: Unable to autoload constant Importer::Transformer, expected [rails_dir]/lib/importer/transformer.rb to define it
Of course, /lib/importer/transformer.rb does define it

For example, I get this error (sometimes) when running the whole suite
LoadError: Unable to autoload constant Importer::Exceptions, expected [rails_dir]/lib/importer/exceptions.rb to define it # ./spec/transforms/any_to_ton_transform_spec.rb:76:inblock (2 levels) in <top (required)>'`

But if I then run rspec spec/transforms/any_to_ton_transform_spec.rb specifically all tests pass and there is no LoadError, so it seems something is up with the autoloader if I run the whole suite but not a single spec file. Am I doing something wrong in my spec_helper or rails_helper or is something else going on?

I have tried to add any relevant information in this post and I'm curious if anyone else has this problem or whether I did something to cause this? Any help would be appreciated, thanks :)

spec_helper.rb source

require 'simplecov'
SimpleCov.start
RSpec.configure do |config|
  config.expect_with :rspec do |expectations|
    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
  end

  config.mock_with :rspec do |mocks|
    mocks.verify_partial_doubles = true
  end

  config.shared_context_metadata_behavior = :apply_to_host_groups

  config.example_status_persistence_file_path = "spec/examples.txt"
  config.disable_monkey_patching!
  config.order = :random
  Kernel.srand config.seed

  config.filter_run_including focus: true
  config.run_all_when_everything_filtered = true
end

rails_helper.rb source

ENV['RAILS_ENV'] ||= 'test'
require File.expand_path('../../config/environment', __FILE__)
abort("The Rails environment is running in production mode!") if Rails.env.production?
require 'spec_helper'
require 'rspec/rails'

require 'support/controllers_helper'
Dir[Rails.root.join('spec/support/**/*.rb')].each { |f| require f }

ActiveRecord::Migration.maintain_test_schema!

RSpec.configure do |config|
  config.use_transactional_fixtures = true
  config.infer_spec_type_from_file_location!
  config.filter_rails_from_backtrace!
  config.include ControllersHelper, type: :controller

  config.include FactoryGirl::Syntax::Methods

  config.include JsonSpec::Helpers
  config.include FileHelpers
  config.include ParserHelper, type: :parser
  config.include ActionHelper, type: :action

  config.after { Temping.teardown }
end

config/application.rb source

require File.expand_path('../boot', __FILE__)

require "rails"
require "active_model/railtie"
require "active_record/railtie"
require "action_controller/railtie"
require "action_mailer/railtie"

Bundler.require(*Rails.groups)

module MyApplication
  class Application < Rails::Application
    ActiveSupport.parse_json_times
    config.autoload_paths += %W[
      #{config.root}/app/serializers
      #{config.root}/app/transforms
      #{config.root}/app/transforms/concerns
      #{config.root}/app/transforms/sub_transforms
      #{config.root}/app/parsers
      #{config.root}/app/parsers/wagons
      #{config.root}/app/actions
      #{config.root}/lib
    ]

    config.action_dispatch.perform_deep_munge = false

    config.active_job.queue_adapter = :delayed_job

    config.middleware.insert_after Rails::Rack::Logger, Rack::Cors do
      allow do
        origins '*.myapplicat.io', 'localhost:*', '*'
        resource '*',
          headers: :any,
          methods: %i(get post put patch delete head options)
      end
    end
  end
end

any_to_ton_transform.rb source

class AnyToTonTransform
  def self.execute(value)
    return value if value.is_a?(Numeric) || value.nil?

    value = value.gsub('.', '') if %w(, .).all? { |c| value.include? c }

    BigDecimal.new(value.gsub(',', '.'))
  rescue
    raise Importer::Exceptions::TransformError,
      'value could not be converted into number'
  end
end

any_to_ton_transform_spec.rb source

require 'rails_helper'

RSpec.describe AnyToTonTransform do

  def execute(value)
    described_class.execute(value)
  end

  example 'ignores numbers' do
    expect(execute 12).to be 12
  end

  example 'ignores nil' do
    expect(execute nil).to eq nil
  end

  example '"0" -> 0' do
    expect(execute '0').to eq 0
  end

  example '"1" -> 1' do
    expect(execute '1').to eq 1
  end

  example '"22" -> 22' do
    expect(execute '22').to eq 22
  end

  example '"123.456" -> 123.456' do
    expect(execute '123.456').to eq 123.456
  end

  example '"456,7" -> 456.7' do
    expect(execute '456,7').to eq 456.7
  end

  example '"2.346,1" -> 2346.1' do
    expect(execute '2.346,1').to eq 2346.1
  end

  example '"2.346,8" -> 2346.8' do
    expect(execute '2.346,8').to eq 2346.8
  end

  example '"7,7" -> 7.7' do
    expect(execute '7,7').to eq(7.7)
  end

  example '"7,1" -> 7.1' do
    expect(execute '7,1').to eq(7.1)
  end

  example '"7.7" -> 7.7' do
    expect(execute '7.7').to eq(7.7)
  end

  example '"7.0" -> 7' do
    expect(execute '7.0').to eq(7)
  end

  example '"7.1" -> 7.1' do
    expect(execute '7.1').to eq(7.1)
  end

  example '"7.22" -> 7.22' do
    expect(execute '7,22').to eq(7.22)
  end

  example '"7.231" -> 7.231' do
    expect(execute '7.231').to eq(7.231)
  end

  it "throws an exception for invalid input" do
    expect{
      execute({})
    }.to raise_error(Importer::Exceptions::TransformError)
  end
end

/lib/importer/exceptions.rb source

module Importer
  module Exceptions
    class CustomError < StandardError
      def severity
        self.is_a?(FatalError) ? :fatal : :warning
      end

      def as_json(_ = nil)
        { message: message, severity: severity }
      end

      def to_json
        JSON.dump(as_json)
      end
    end

    FatalError       = Class.new(CustomError)
    InvalidCellError = Class.new(FatalError)
    InvalidRowError  = Class.new(FatalError)
    InvalidFileError = Class.new(FatalError)

    WarningError   = Class.new(CustomError)

    class TransformError < WarningError
      attr_accessor :value,
                    :transform

      def as_json(_ = nil)
        {
          message:   message,
          severity:  severity,
          value:     value,
          transform: transform
        }
      end
    end
  end
end

[JonRowe]

Honestly I'm not sure theres much we can do to help with this, the Rails autoloader is notorious for producing odd issues like this, but I can suggest a few things that might work as a work around:

• try eager loading in the test environment (e.g. like production) so it loads things earlier on (or hopefully at least consistently?)
• explicitly requiring files in your specs

[grandconjuration]

Thanks for the suggestions, I'll give them a try! 👍