no implicit conversion of nil into String

[sarjanen]

Got this error on rc3 but not on rc2 and I do not do anything fancy here:

class PostSerializer < ActiveModel::Serializer
  attributes :id
end

class Api::V2::PostsController < ApplicationController
  def index
    post = Post.all

    render json: post
  end
end

Application trace:

app/serializers/post_serializer.rb:1:in `<top (required)>'
app/controllers/api/v2/posts_controller.rb:5:in `index'

I get the same error on every adapter

[NullVoxPopuli]

hi, @Padchi,

I'm having issues replicated our error with the given information.

A few questions:

• Do any other serializers have this issue?
• Could you post your Post model?
• Could you post your Post schema entry? (just to see what fields exist on the model)
• Is it only when you render the result of a {model}.all?

[bf4]

Is the id actually nil?

Might be related to 995bbcc

btw, Post.all might not be a good idea, unless you mean that just as example code

[sarjanen]

Hello @NullVoxPopuli and @bf4!

Do any other serializers have this issue?

All my serializers have the same problem.

Could you post your Post model?

class Post < ActiveRecord::Base
  nilify_blanks

  belongs_to :user
  has_many :comments, as: :commentable, dependent: :destroy
  has_many :attachments, as: :attachable, dependent: :destroy

  extend FriendlyId
  friendly_id :title, use: :slugged

  validates :content, :title, :published_on, presence: true

  before_save :downcase_tags

  private

    def downcase_tags
      self.tags.map!(&:downcase) unless self.tags.blank?
    end 
end

Could you post your Post schema entry? (just to see what fields exist on the model)

  create_table "posts", id: :uuid, default: "uuid_generate_v4()", force: :cascade do |t|
    t.string   "title",        limit: 255
    t.text     "content"
    t.string   "image",        limit: 255
    t.datetime "created_at"
    t.datetime "updated_at"
    t.uuid     "user_id"
    t.string   "slug",         limit: 255
    t.date     "published_on"
    t.string   "tags",         limit: 255, default: [], array: true
  end

  add_index "posts", ["slug"], name: "index_posts_on_slug", using: :btree
  add_index "posts", ["tags"], name: "index_posts_on_tags", using: :gin

Is it only when you render the result of a {model}.all?

No i tried with a simple show action as well.

Is the id actually nil?

No posts in my database has a null id.

btw, Post.all might not be a good idea, unless you mean that just as example code

That's just my simplified example, but i got the same error with my real code

[bf4]

B mobile phone

On Sep 18, 2015, at 2:30 PM, Timmie Sarjanen notifications@github.com wrote:

No posts in my database has a null id.

Ok, but if you

def id 
  fail object.id.inspect
end

in your PostSerializer, what do you get?

[sarjanen]

@bf4 Exactly the same thing unfortunately

[bf4]

That tells me that your object.id is nil :)

[sarjanen]

@bf4 I don't get it. If my posts table is empty i just get a response with {"data": [] } and then i tried to add a record in the console and the new record got a ID but i get the same error?

[sarjanen]

@bf4 and @NullVoxPopuli i have replicated the error, you can find it here https://github.com/Padchi/ams-test/tree/master

[beauby]

Will look into it in an hour.

[dukex]

Hi @Padchi I cant reproduce the error using your test repo.

I did:

$ bundle install
$ rake db:migrate
$ rails s

The GET /posts is OK, returning a empty JSON object

$ rails c
irb(main): Post.create
irb(main): Post.create
irb(main): Post.create
irb(main): Post.create
irb(main): Post.create

The GET /posts is OK, returning 5 object

{"data":[{"id":"1","type":"post"},{"id":"2","type":"post"},{"id":"3","type":"post"},{"id":"4","type":"post"},{"id":"5","type":"post"}]}

[sarjanen]

@dukex how is that even possible? I used a fresh clean gemset and i guess that you use the same ruby version as specified in the gemfile?

[chenghung]

the same problem on 0.10.0 rc3

[dukex]

Yes @Padchi, using the ruby 2.2.1.p85.

Look my screenshot

[sarjanen]

@chenghung it's only on rc3 for me, not on rc2

[sarjanen]

@dukex I tested the repo on ruby 2.2.3 to and it's the same problem so don't think that's ruby is the problem. But still thinks it's wierd that you don't get the error with the same repo as me.