Using ruby to test python on file changes

watch.rb

#!/usr/bin/env ruby

# REQUIREMENTS
#
# Needs ruby and the watchr gem, which can be installed
# globally via:
#
# sudo gem install watchr

# USAGE
#
# watchr watch.rb

dep = Gem::Dependency.new("watchr", "~>0.7.0")
unless dep.matching_specs.max_by(&:version)
  puts "You need to install '#{dep}'"
  puts "e.g. 'sudo gem install watchr'"
  exit!
end

IGNORED_DIRS = ["./bin", "./docs"]
IGNORED_PATTERNS = [/__pycache__/,
                    /.egg-info/]

is_watched = Proc.new do |f|
  File.directory?(f) &&
    IGNORED_DIRS.none? { |d| f.start_with?(d) } &&
    IGNORED_PATTERNS.none? { |p| p.match(f) }
end

test_dirs, code_dirs = Dir["./**/*"].select(&is_watched).
                         map { |d| d[2..-1] }.
                         partition { |d| d.start_with?("tests") }

puts "Watching test dirs: #{test_dirs}"
puts "Watching code dirs: #{code_dirs}"


pytest = "py.test -svv --run-slow --skip-launch --skip-tear-down"

test_dirs.map { |d| /#{d}\/test_.+\.py$/ }.each do |to_watch|
  watch(to_watch) do |md|
    system("#{pytest} #{md[0]}")
  end
end

code_dirs.map { |d| /#{d}\/.+\.py$/ }.each do |to_watch|
  watch(to_watch) do |md|
    system("flake8") && system("pep257") && system(pytest)
  end
end