mysql_deepmerge.rb

require_relative '../../../puppet_x/puppetlabs/mysql_utilities'
module Puppet::Parser::Functions
  newfunction(:mysql_deepmerge, type: :rvalue, doc: <<-'ENDHEREDOC') do |args|
    @summary Recursively merges two or more hashes together and returns the resulting hash.

    @example
        $hash1 = {'one' => 1, 'two' => 2, 'three' => { 'four' => 4 } }
        $hash2 = {'two' => 'dos', 'three' => { 'five' => 5 } }
        $merged_hash = mysql_deepmerge($hash1, $hash2)
        # The resulting hash is equivalent to:
        # $merged_hash = { 'one' => 1, 'two' => 'dos', 'three' => { 'four' => 4, 'five' => 5 } }

    - When there is a duplicate key that is a hash, they are recursively merged.
    - When there is a duplicate key that is not a hash, the key in the rightmost hash will "win."
    - When there are conficting uses of dashes and underscores in two keys (which mysql would otherwise equate),
      the rightmost style will win.

    @return [Hash]
    ENDHEREDOC

    if args.length < 2
      raise Puppet::ParseError, _('mysql_deepmerge(): wrong number of arguments (%{args_length}; must be at least 2)') % { args_length: args.length }
    end

    result = {}
    args.each do |arg|
      next if arg.is_a?(String) && arg.empty? # empty string is synonym for puppet's undef
      # If the argument was not a hash, skip it.
      unless arg.is_a?(Hash)
        raise Puppet::ParseError, _('mysql_deepmerge: unexpected argument type %{arg_class}, only expects hash arguments.') % { args_class: args.class }
      end

      # Now we have to traverse our hash assigning our non-hash values
      # to the matching keys in our result while following our hash values
      # and repeating the process.
      PuppetX::Puppetlabs::MysqlUtilities.overlay(result, arg)
    end
    return(result)
  end
end