Yesterday I released a simple gem that adds RSpec custom matchers for Ruby encodings. It’s got the amazingly creative title of rspec-encoding-matchers. It’s nothing fancy, but does make it easy to test the encoding of strings in RSpec and Ruby 1.9.

The gem adds a couple matchers. There is the simple matcher to check if a string is encoded in the right encoding:

# Matcher takes the name of a supported Ruby encoding as a string or symbol
"my string".should be_encoded_as("UTF-8")

Or there is also a long list of be_xxxxxxx_encoded matchers to check if a string is of a certain encoding:

"my string".should be_binary_encoded
"my string".should be_stateless_iso_2022_jp_encoded
# ...repeat for all supported Ruby encodings

The full list of 163 matchers is available in the readme.

To use the custom matchers in your specs, simply include the matcher module either in an example group:

describe "my group" do
  include RspecEncodingMatchers
  it "is encoded in UTF-8" do
    hello.should be_encoded_as("UTF-8")
  end
end

Or you can include the module in your RSpec configuration.

# spec_helper.rb
RSpec.configure do |config|
  config.color_enabled = true
  config.include RSpecEncodingMatchers
end