ActiveRecord::AssociationTypeMismatch gotNilClass - ruby-on-rails

Question

I am a beginner programmer in Ruby and Ruby on Rails , I'm trying to run a rake command in my task , but when I do the following happens:
rake daily_tasks:process_api
rake aborted!
ActiveRecord::AssociationTypeMismatch: Estado(#47392639701120) expected, got NilClass(#47392580444120)
/home/thiagoamaralr/Desktop/proponente-master-4f8a3b2ddb02a90b2c173cf31383505018d02dd/app/services/create_programa_api.rb:21:in `call'
/home/thiagoamaralr/Desktop/proponente-master-74f8a3b2ddb02a90b2c173cf31383505018d02dd/lib/tasks/daily_tasks.rake:7:in `block (3 levels) in <top (required)>'
/home/thiagoamaralr/Desktop/proponente-master-74f8a3b2ddb02a90b2c173cf31383505018d02dd/lib/tasks/daily_tasks.rake:5:in `each'
/home/thiagoamaralr/Desktop/proponente-master-74f8a3b2ddb02a90b2c173cf31383505018d02dd/lib/tasks/daily_tasks.rake:5:in `block (2 levels) in <top (required)>'
Tasks: TOP => daily_tasks:process_api
(See full trace by running task with --trace)
Follow the task I'm trying to run:
namespace :daily_tasks do
desc "Process the day to day tasks"
task process_api: :environment do
SiconvApi::Programa.find.each do |programa|
if programa.data_inicio_recebimento_propostas && (programa.data_inicio_recebimento_propostas.to_date >= Date.parse("2015/06/01"))
CreateProgramaApi.call(SiconvApi::Serializers::Programa.new(programa))
end
end
end
end
And this is content create_programa_api.rb:
class CreateProgramaApi
def self.call(programa_api)
params = programa_api.to_h
params[:orgao] = Orgao.where("lower(name) = ?", programa_api[:orgao][:nome].mb_chars.downcase).first_or_create(name: programa_api[:orgao][:nome])
params[:orgao_vinculado] = Orgao.where("lower(name) = ?", programa_api[:orgao_vinculado][:nome].mb_chars.downcase).first_or_create(name: programa_api[:orgao_vinculado][:nome])
params[:orgao_executor] = Orgao.where("lower(name) = ?", programa_api[:orgao_executor][:nome].mb_chars.downcase).first_or_create(name: programa_api[:orgao_executor][:nome])
params[:estados] = []
if programa_api[:estados].size == 27
params[:estados] << Estado.find_by(sigla: 'Todos')
else
programa_api[:estados].each do |e|
params[:estados] << Estado.find_by(sigla: e)
end
end
params[:atendes] = [Atende.where("lower(name) = ?", programa_api[:atende_a].mb_chars.downcase).first_or_create(name: programa_api[:atende_a])] if programa_api[:atende_a]
params.delete(:atende_a)
programa = Programa.find_by(codigo: programa_api[:codigo])
if programa
programa.update(params)
else
Programa.create! params
end
end
end
Thanks for your attention!

Answer 1

You have nil object in params[:estados], and Rails can't save this association.
Easiest way to remove them is to call params[:estados].compact! after line 14

Answer 2

This block of code is your problem:
params[:estados] = []
if programa_api[:estados].size == 27
params[:estados] << Estado.find_by(sigla: 'Todos')
else
programa_api[:estados].each do |e|
params[:estados] << Estado.find_by(sigla: e)
end
end
If no record is found, the #find_by returns nil. This is why you are getting the error:
ActiveRecord::AssociationTypeMismatch: Estado(#47392639701120) expected, got NilClass
When calling Programa.create!(params).
One solution would be to call params[:estados].compact! after the if statement (this is using Array#compact! to remove any nil values).
Or, you could instead write that section of code like this:
params[:estados] = Estadio.where(
sigla: (programa_api[:estados].size == 27 ? 'Todos' : programa_api[:estados])
)
With this code, there is no longer a need to call compact! since we already end up with an empty array if no records are found (i.e. there are no nil values).
Note that the behaviour here isn't quite the same - what happens if there are multiple Estado records with the sigla equal to one of programa_api[:estados] or 'Todos'? Previously you were only fetching the "first" such record, whereas now you'd be fetching all of them. This may not be an issue (or may even be the correct behaviour!!) - it's just something to be aware of, at least.