RSpec Shared Example Matcher for Class Constant Definition

rspec_shared_example_defined_constants.rb

# Shared specs for models with frozen CONST values. Expects two String values
#  as parameters. 
RSpec.shared_examples :has_const_model do |const_name, const_value|

  it { expect(described_class).to be_const_defined(const_name.to_sym) }
  it { expect("#{described_class}::#{const_name}".constantize).to be_frozen }
  it { expect("#{described_class}::#{const_name}".constantize).to eq(const_value) }

end

This is for expressing a specification for a Ruby Class that holds a "const" value. E.g.,

class DoStuffService

  OFTEN_ACCESSED_STRING = "I use this value all over the place".freeze

  ...

end

...and you would like that expressed in your specs :)