why the method column_types is undefined in Rails 5.0?

Question

Im doing an assignment for a class and it uses column_types method in a rspec test.

  it "User database structure in place" do
        expect(User.column_names).to include "password_digest", "username"
        expect(User.column_types["username"].type).to eq :string
        expect(User.column_types["password_digest"].type).to eq :string
        expect(User.column_types["created_at"].type).to eq :datetime
        expect(User.column_types["updated_at"].type).to eq :datetime

end

Error: when i run rpsec in the command line.
Rails 5.0
Ubuntu 14.10

Failure/Error: expect(User.column_types["username"].type).to eq :string

 NoMethodError:
   undefined method `column_types' for #<Class:0x000000053a0188>
   Did you mean?  columns
                  column_names
 # ./spec/assignment_spec.rb:67:in `block (5 levels) in <top (required)>'
 # ./spec/assignment_spec.rb:14:in `block (2 levels) in <top (required)>'

Answer 1

The method was removed in this commit. It's not so easy to find it.

But, the reason is was not documented, it's because the method itself is not documented (Maybe it's just for internal use).

See this comment :nodoc: on the method when it existed:

def column_types # :nodoc:
    @column_types ||= columns_hash.transform_values(&:cast_type).tap do |h|
      h.default = Type::Value.new
    end
  end

You can read through the commit's description to understand the why and maybe see if there's something else you can do.

EDIT

Take a look at these lines maybe attributes_types or columns_hash can solve your problem.

Answer 2

The method column_types is removed in Rails 5.

To get the type of column you can try following code:

User.column_for_attribute('username').type

This will return the type, here in your case: :string

Answer 3

looks like in rails 5, column_types method no longer exist