Method: LibGems::DependencyList#dependency_order

Defined in:
lib/libgems/dependency_list.rb

#dependency_order ⇒ Object

Return a list of the gem specifications in the dependency list, sorted in order so that no gemspec in the list depends on a gemspec earlier in the list.

This is useful when removing gems from a set of installed gems. By removing them in the returned order, you don’t get into as many dependency issues.

If there are circular dependencies (yuck!), then gems will be returned in order until only the circular dependents and anything they reference are left. Then arbitrary gemspecs will be returned until the circular dependency is broken, after which gems will be returned in dependency order again.



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# File 'lib/libgems/dependency_list.rb', line 68

def dependency_order
  sorted = strongly_connected_components.flatten

  result = []
  seen = {}

  sorted.each do |spec|
    if index = seen[spec.name] then
      if result[index].version < spec.version then
        result[index] = spec
      end
    else
      seen[spec.name] = result.length
      result << spec
    end
  end

  result.reverse
end