LipsumBlender / code test for Position Development (I did not get an offer)

lipsum_blender.rb

# LipsumBlender
# Dan Phiffer <[email protected]>
# August 2015

# LipsumBlender watches the current directory for .txt files, and accumulates
# the file contents into an internal corpus. This corpus is used to randomly
# generate a paragraph of 10 sentences, each containing 10 words. The frequency
# of the word selection is based on how commonly words appear within the
# aggregate input texts.

# +---------------------------------------------------------------------------+
# | n.b.: this will delete the .txt file after it finishes, so don't put      |
# |       anything precious into the folder.                                  |
# +---------------------------------------------------------------------------+

# Usage: ruby lipsum_blender.rb

require 'directory_watcher'

class LipsumBlender

	def initialize()
		@corpus = []
		@dir_watcher_target = '.'
		@dir_watcher_options = {
			:glob => '*.txt',
			:interval => 1
		}
		@downcase_exceptions = [
			'I'
		]
		start_watching
	end
	
	def start_watching()
		
		# Watch for incoming files
		dw = DirectoryWatcher.new @dir_watcher_target, @dir_watcher_options
		dw.add_observer do |*args|
			args.each do |event|
				
				# We found a file, let's do some stuff with it
				found_text_file event
				
				# All done, we can delete the file now
				if File.exists? event.path then
					File.delete event.path
				end
				
			end
		end
		
		dw.start
		puts "I gobble up .txt files in the current directory and turn them into lipsum."
		puts "Press enter key to exit.\n"
		gets # Wait for an enter key press
		dw.stop
	end
	
	def found_text_file(event)
		
		# Only operate on newly added files
		return unless event.added?
		
		# Read the file, strip out punctuation, and grab all the words
		content = File.read event.path
		content.gsub! /\s/, ' '              # Normalize whitespace
		content.gsub! /[^A-Za-z ]/, ''       # Remove non-alpha chars
		@corpus += content.scan /[A-Za-z]+/  # Find consecutive alpha chars
		
		# Output a random paragraph
		puts
		puts wrap get_random_paragraph
	end
	
	def get_random_paragraph()
		# Returns a paragraph of 10 sentences
		sentences = []
		10.times do
			sentences.push get_random_sentence
		end
		sentences.join ' '
	end
	
	def get_random_sentence()
		# Returns a capitalized sentence, with a trailing period.
		words = []
		10.times do
			
			# Pick a random word from the word corpus
			index = rand @corpus.length
			word = @corpus[index]
			
			if (words.empty?) then
				word.capitalize! # Capitalize the first word
			elsif @downcase_exceptions.find_index(word).nil?
				word.downcase!   # Lowercase everything else
			end
			words.push word
		end
		
		words.join(' ') + '.'
	end
	
	# From the Ruby Cookbook
	# https://www.safaribooksonline.com/library/view/ruby-cookbook/0596523696/ch01s15.html
	def wrap(s, width=80)
		s.gsub(/(.{1,#{width}})(\s+|\Z)/, "\\1\n")
	end
	
end

# Let's blend!
lb = LipsumBlender.new