Embedded elements for a write-up on cucumber and rspec for bash testing

bin_fizzbuzz.sh

#!/bin/bash

FIZZBUZZLIB="${FIZZBUZZLIB:-/usr/local/lib/fizzbuzz}"

source "${FIZZBUZZLIB}/fizzbuzz.inc.sh"

fizzbuzz $1

features_step_definitions_fizzbuzz_steps.rb

When /^I say "([^\"]*)"$/ do |number|
  @procinfo = ShellRunner.run( "FIZZBUZZLIB=\"#{FIZZBUZZLIB}\" #{FIZZBUZZ} #{number}" )
end

Then /^I should see "([^\"]*)"$/ do |response|
  @procinfo[:output].should include("#{response}")
end

features_support_env.rb

# Set up some paths

BINDIR = File.expand_path('../../../bin', __FILE__)
VENDORDIR = File.expand_path('../../../vendor', __FILE__)
FIZZBUZZLIB = "#{BINDIR}/../lib"

# Set up our Bash script reference

FIZZBUZZ = "#{BINDIR}/fizzbuzz.sh"

# Do up the general environment

$LOAD_PATH.unshift "#{VENDORDIR}/lib"

require 'shellrunner'

features_user_passes_a_number.feature

Feature: user passes a number

  The user passes a number that is greater-than 0 to fizzbuzz on the
  command-line.  Fizzbuzz then responds with "Fizz" if the number is
  a multiple of 3, "Buzz" if the number is a multiple of 5, "FizzBuzz"
  if the number is a multiple of both 3 and 5, or the number itself
  otherwise.
  
  Scenario Outline: pass a number
    When I say "<number>"
    Then I should see "<response>"
    
    Scenarios: response is "Fizz"
      | number | response |
      | 3      | Fizz     |
      | 6      | Fizz     |
      | 9      | Fizz     |
      | 12     | Fizz     |
      | 18     | Fizz     |
    
    Scenarios: response is "Buzz"
      | number | response |
      | 5      | Buzz     |
      | 10     | Buzz     |
      | 20     | Buzz     |
      | 25     | Buzz     |
      | 35     | Buzz     |
    
    Scenarios: response is "FizzBuzz"
      | number | response |
      | 15     | FizzBuzz |
      | 30     | FizzBuzz |
      | 45     | FizzBuzz |
      | 60     | FizzBuzz |
      | 75     | FizzBuzz |
    
    Scenarios: response is the input number
      | number | response |
      | 14     | 14       |
      | 29     | 29       |
      | 44     | 44       |
      | 59     | 59       |
      | 94     | 94       |

fizzbuzzdirs.txt

fizzbuzz
  -bin
  -features
    -support
    -step_definitions
  -lib
  -spec
    -fizzbuzz
  -vendor
    -lib
    -bin

lib_fizzbuzz.inc.sh

fizz() {
  [ $(( $1 % 3 )) -eq 0 ] 
}

buzz() {
  [ $(( $1 % 5 )) -eq 0 ]
}

fizzbuzz() {
  local fb=''
  fizz "${1}" && fb="Fizz"
  buzz "${1}" && fb="${fb}Buzz"
  [ -n "${fb}" ] && echo "${fb}" || echo "${1}"
}

spec_fizzbuzz_fizzbuzz_spec.rb

require 'spec_helper'

module Fizzbuzz
  def fizz
  end

  describe "#fizz" do
    context "number is a multiple of 3" do
      it "has an exit code of 0 for true" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh fizz 3")
        @procinfo[:exitstatus].should ==(0)
      end
    end
    
    context "number is not a multiple of 3" do
      it "has an exit code of 1 for false" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh fizz 1")
        @procinfo[:exitstatus].should ==(1)
      end
    end
  end

  def buzz
  end
  
  describe "#buzz" do
    context "number is a multiple of 5" do
      it "has an exit code of 0 for true" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh buzz 5")
        @procinfo[:exitstatus].should ==(0)
      end
    end
    
    context "number is not a multiple of 5" do
      it "has an exit code of 1 for false" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh buzz 1")
        @procinfo[:exitstatus].should ==(1)
      end
    end
  end

  def fizzbuzz
  end
  
  describe "#fizzbuzz" do
    context "number is a multiple of 3 but not 5" do
      it "outputs 'Fizz'" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh fizzbuzz 3")
        @procinfo[:output].should include("Fizz")
      end
    end
    
    context "number is a multiple of 5 but not 3" do
      it "outputs 'Buzz'" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh fizzbuzz 5")
        @procinfo[:output].should include("Buzz")
      end
    end
    
    context "number is a multiple of both 3 and 5" do
      it "outputs 'FizzBuzz'" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh fizzbuzz 15")
        @procinfo[:output].should include("FizzBuzz")
      end
    end
    
    context "number is a multiple of neither 3 nor 5" do
      it "echoes the provided number" do
        @procinfo = ShellRunner.run("#{DOMETHOD} #{FIZZBUZZLIB}/fizzbuzz.inc.sh fizzbuzz 1")
        @procinfo[:output].should include("1")
      end
    end
  end
end

spec_spec_helper.rb

VENDORDIR = File.expand_path('../../vendor', __FILE__)
FIZZBUZZLIB = "#{VENDORDIR}/../lib"

DOMETHOD = "#{VENDORDIR}/bin/domethod.sh"

$LOAD_PATH.unshift "#{VENDORDIR}/lib"

require 'shellrunner'

vendor_bin_domethod.sh

#!/bin/bash - 
#===============================================================================
#
#          FILE:  domethod.sh
# 
#         USAGE:  ./domethod.sh library_to_test method arg1 arg2 ... argN
# 
#   DESCRIPTION:  A quick-n-dirty evaluator to provide the ability to use rspec
# 
#===============================================================================

die() {
  echo -e "Error: ${1}" >&2
  exit 255
}

method_exists() {
  [ "$( declare -F "${1}" )" == "${1}" ]
}

TESTLIB="${1}" && shift
METHOD="${1}" && shift

source "${TESTLIB}"

method_exists "${METHOD}" || die "Method '${METHOD}' does not exist."

"${METHOD}" "${@}"

vendor_lib_shellrunner.rb

require 'open4'

class ShellRunner
  attr_reader :output, :error, :exitstatus, :command

  def initialize( command  )
    @command = command
    @output = Array.new
    @error = Array.new
    @exitstatus=-1
  end

  def run
    pid, stdin, stdout, stderr = Open4::popen4 "#{ @command }"
    status = Process::waitpid2(pid)[1] 
    @exitstatus = ( status.to_i / 256 )
    @output += io_to_a(stdout)
    @error += io_to_a(stderr)
    self.to_h
  end

  def to_h
    {
      :exitstatus => @exitstatus, 
      :output => @output,
      :error => @error
    }
  end

  def self.run(command)
    self.new(command).run
  end

  private

  def io_to_a(io)
    io.readlines.collect { |x| x.chomp }
  end

end