Solution to query_to_hash problem.

query_to_hash.rb

# This file is an rspec runnable file.
# (I didn't name it with _spec because its primary purpose is to provide
# the method, not run the test.)


# Here's the function that solves the problem, and the require needed to run it.

require 'uri'

def query_to_hash(query)
  params = query.split('&')
  params.inject({}) do |hash, expression|
    key, escaped_value = expression.split('=')
    unescaped_value = URI::unescape(escaped_value)
    hash[key] = unescaped_value
    hash
  end
end


# Here's a simple rspec test that verifies the correctness of the provided example.

require 'rspec'


describe "Query to Hash" do
  
  SAMPLE_STRING = "foo=bar&abc=1%202%203"
  
  it "should return a hash containing the correct key/value pairs" do
    expected = { "foo" => "bar", "abc" => "1 2 3" }
    query_to_hash(SAMPLE_STRING).should == expected
  end
end