Collecting hashes into OpenStruct creates "table" entry

Because @table is a instance variable of OpenStruct and Object#as_json returns Hash of instance variables.

In my project, I implemented OpenStruct#as_json to override the behaviour.

require "ostruct"
class OpenStruct
  def as_json(options = nil)
    @table.as_json(options)
  end
end

Use marshal_dump, although this somewhat defeats the purpose of converting it to an OpenStruct beforehand:

[{:a => :b}].collect {|x| OpenStruct.new(x).marshal_dump }.to_json
=> "[{\"a\":\"b\"}]"

The shorter way would be:

[{:a => :b}].to_json
"[{\"a\":\"b\"}]"

Alternatively you could moneky patch OpenStruct#as_json as shown in hiroshi's answer:

require "ostruct"
class OpenStruct
  def as_json(options = nil)
    @table.as_json(options)
  end
end

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