CODEWITHSUNDEEP
rubychef-infrayaml
zealouscoder
zealouscoder

Reputation: 94

TypeError: no implicit conversion of false into Hash

I am learning ruby and fairly new to coding in it. Below is the chef recipe that I wrote to merge two hashes and write to YAML file. 

 yaml_string = "AVG_METRICS: 
 get_requests:
 - OneMinuteRate
 - FifteenMinuteRate"

 trimmed_custom_hash = YAML.load(yaml_string)
 ruby_block do
     merger = proc do |key,v1,v2|
          Hash === v1 && Hash === v2 ? v1.merge(v2, &merger) : v2
     end
     block do
         if test_string.start_with? "7."
            default_hash = YAML.load_file(File.join('/opt/tests/metrics','metrics_test.yml'))
            default_hash.merge!(trimmed_custom_hash, &merger)
            File.open("/opt/tests/metrics/metrics_test.yml", "w") { |file| file.write(default_hash.to_yaml)}
         end
    end
end

I am unable to understand why the implicit conversion error occurs. I have come up with questions when considering possibilities of where it might be failing.

  1. What would be the return value of this block?
  2. If an if condition has "?", then is the block supposed to return only true or false?
  3. Are there any points that I need to remember when using ruby_block in chef?

I have been trying to figure this out for a while. It would be great if you could point me to where the error might be. Thanks!

Upvotes: 0

Views: 1863

Answers (1)

spickermann
spickermann

Reputation: 106872

An error like this is raised when merge is called on a hash with false as an argument:

{}.merge(false)
#=> TypeError (no implicit conversion of false into Hash)

I would expect the error to be in the line v1.merge(v2, &merger) or in default_hash.merge!(trimmed_custom_hash, &merger). Why does it happen? Hard to tell without knowing how trimmed_custom_hash is defined.

It is a common Ruby idiom that methods ending with an ? should return a boolean. But I would rely on this because it is just a convention and it isn't enforced by the language itself.

Upvotes: 5

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