💎 Minimal Pure Ruby Testing

_ Minimal Pure Ruby Testing _.md

Minimal Ruby Testing 💎

...because Ruby doesn't ship with a testing framework (anymore)

$ testing.rb is 50 lines of code

require "testing"

test "String equal?" do
  assert "hello" == "hello"
end

test "Are these numbers equal?" do
  assert 5 == 6
end

test "This is pending, I'll do it later"

test "Describe why it blew up" do
  assert 1 == 2, "number equality"
end

$ ruby mytest.rb

String equal? [OK]

Are these numbers equal? [FAIL]
assertion failed @ mytest.rb:8
=> assert 5 == 6

This is pending, I'll do it later [PENDING]
Describe why it blew up [FAIL]
number equality @ mytest.rb:14
=> assert 1 == 2, "number equality"

testing.rb

#! /usr/bin/env ruby
# Minimal Testing – Pure Ruby 💎 (50 LOC)
def green  message; "\e[32m#{message}\e[0m"; end
def red    message; "\e[31m#{message}\e[0m"; end
def yellow message; "\e[33m#{message}\e[0m"; end
class AssertionError < StandardError; end
def assert condition, message = "assertion failed"
  raise AssertionError, message unless condition
end
def assert_equals a, b, message = nil
  assert a == b, "Expected #{a.inspect} to equal #{b.inspect}"
end
def assert_contains collection, item, message = nil
  assert collection.include?(item),
         "Expected #{collection.inspect} to include #{item.inspect}"
end
def tests; $_tests_ ||= {}; end
def test description, &block; tests[description] = block; end
def print_error e
  print e.message
  e.backtrace.detect {|l| l =~ /^(?<filepath>\w+\.rb):(?<line_number>\d+)/ }
  if $1
    puts " @ #{$1}:#{$2}" if $1
    puts "=> " + File.read($~[:filepath]).lines[$~[:line_number].to_i - 1].strip
  end
  puts
  puts e.backtrace if ENV["VERBOSE"] == "true"
end
def run_tests!
  all_passed = true
  tests.select {|d,b| if m = ENV["MATCH"]; d.include? m; else; true; end }.
    each do |description, block|
    begin
      if block.nil?; puts "#{description} [#{yellow "PENDING"}]"; next; end
      print "#{description} "
      block.call
      puts "[#{green "OK"}]\n\n"
    rescue AssertionError => e
      all_passed = false
      puts "[#{red "FAIL"}]"
      print_error e
    rescue Exception => e
      all_passed = false
      puts "[#{red "ERROR"}]"
      print_error e
    end
  end
  exit 1 unless all_passed
end
at_exit { run_tests! }