chromebrew/tests/cycle_test.rb

#!/usr/bin/env ruby

# This test checks whether the packages create a dependency cycle.

require 'find'
require_relative '../lib/const'
require_relative '../lib/color'
require_relative '../lib/package'

# Add >LOCAL< lib to LOAD_PATH so that packages can be loaded
$LOAD_PATH.unshift File.join(CREW_LIB_PATH, 'lib')

@all_pkgs = {}

puts "Running dependency cycle tests...\n".yellow

# Loads all packages
Dir['../packages/*.rb'].each do |filename|
  name = File.basename(filename, '.rb')
  pkg = Package.load_package(filename)
  @all_pkgs[name] = pkg
end

# Looking for cycles. @path will keep the current dependency path.
# @state will store :on_path for vertices on the current dependency path
# and :visited for vertices that have already been checked not to lead to
# cycles.
@failed = 0
@state = {}
@path = []
@uniq_path = []
def dfs(pkg)
  @path.push(pkg.name)
  case @state[pkg]
  when :on_path
    @path.shift while @path.first != @path.last
    if (!@uniq_path.include? @path.to_s) && @path.to_s.include?(',')
      @uniq_path.push(@path.to_s)
      @failed += 1
    end
  when nil
    @state[pkg] = :on_path
    pkg.dependencies&.each_key do |name|
      dfs(@all_pkgs[name]) if name != pkg.name
    end
    @state[pkg] = :visited
  end
  @path.pop
end

# Calls dfs for every path
@all_pkgs.each_value do |pkg|
  dfs(pkg)
end

# Display dependency cycles
@uniq_path.sort.each do |path|
  puts path.lightred
end

@cycles = 'cycles'
@cycles = 'cycle' if @failed == 1

if @failed.positive?
  abort "\n#{@failed} dependency #{@cycles} found.".lightred
else
  puts "\nNo dependency cycles found.".lightgreen
end