RSpec Application Helper Test: Undefined local variable or method `helper`

Question

This seemed to be a flickering sort of a bug for a while,but now it's appearing consistently: when I run RSpec on a fairly simple ApplicationHelper spec, I get the following error:

% rspec --backtrace
  1) ApplicationHelper renders Markdown from plain text                                                                                                                           
     Failure/Error: expect(helper.md(plaintext)).to eq("<h1 id=\"header\">Header</h1>\n")
     NameError:
       undefined local variable or method `helper' for #<RSpec::ExampleGroups::ApplicationHelper_2:0x000001248d1218>
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-expectations-0f7b78587ab4/lib/rspec/matchers.rb:903:in `method_missing'
     # ./spec/helpers/application_helper_spec.rb:4:in `block (2 levels) in <top (required)>'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:148:in `instance_exec'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:148:in `block in run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:208:in `call'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:208:in `block (2 levels) in <class:Procsy>'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-rails-480b173c9ad6/lib/rspec/rails/adapters.rb:67:in `block (2 levels) in <module:MinitestLifecycleAdapter>'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:292:in `instance_exec'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:292:in `instance_exec'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/hooks.rb:430:in `block (2 levels) in run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:208:in `call'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:208:in `block (2 levels) in <class:Procsy>'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/hooks.rb:432:in `run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/hooks.rb:485:in `run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:301:in `with_around_example_hooks'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example.rb:145:in `run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example_group.rb:494:in `block in run_examples'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example_group.rb:490:in `map'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example_group.rb:490:in `run_examples'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/example_group.rb:457:in `run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/runner.rb:112:in `block (2 levels) in run_specs'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/runner.rb:112:in `map'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/runner.rb:112:in `block in run_specs'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/reporter.rb:49:in `report'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/runner.rb:108:in `run_specs'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/runner.rb:86:in `run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/runner.rb:70:in `run'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/lib/rspec/core/runner.rb:38:in `invoke'
     # /Users/danielsh/.rvm/gems/ruby-2.1.1@project-staging-ng/bundler/gems/rspec-core-4219c4786f6f/exe/rspec:4:in `<top (required)>'
     # /Users/danielsh/Dropbox/Project/Websites/Angular/bin/rspec:20:in `load'
     # /Users/danielsh/Dropbox/Project/Websites/Angular/bin/rspec:20:in `<main>'

Here's the complete spec file (spec_helper is included as part of my .rspec file):

describe ApplicationHelper do
  it 'renders Markdown from plain text' do
    plaintext = '# Header'
    expect(helper.md(plaintext)).to eq("<h1 id=\"header\">Header</h1>\n")
  end
end

This was working up until recently, but I'm not certain what I could have done to break such a basic feature. I'm using edge versions of Rails and RSpec, but didn't see anything in their git repos to suggest that helper had been deprecated---and running rails g helper foo still generates a foo_helper_spec.rb file with instructions indicating that helper contains the helper itself. If anyone has any ideas, I'd be grateful for them!

Answer 1

I created a new Rails project with a fresh RSpec installation, and it led me to the problem. Apparently one of the recent betas introduced a configuration directive called config.infer_spec_type_from_file_location! that was missing from my slightly older spec_helper file; without it, RSpec wasn't guessing the spec type and mixing in the associated methods. Beware breaking changes!

Answer 2

add :type => :helper so your code should look like

describe ApplicationHelper, type: :helper do
 ...
end

Answer 3

That's a weird error !! are you sure you required spec_helper in your spec ?

Anyway you could try without the helper method:

First you should first add to /spec/spec_helper.rb the following:

RSpec.configure do |config|
  ...
  config.include ApplicationHelper
end

Then test without helper , so it will be:

describe ApplicationHelper do
  it 'renders Markdown from plain text' do
    plaintext = '# Header'
    expect(md(plaintext)).to eq("<h1 id=\"header\">Header</h1>\n")
  end
end