Superclass mismatch, Struct, reloading and Spork

class, inheritance, ruby, spork

Solution

`Struct.new` is creating new class for your every load.

irb(main):001:0> class Test1 < Struct.new :id; end
nil
irb(main):003:0> class Test1 < Struct.new :id; end
TypeError: superclass mismatch for class Test1
    from (irb):3
    from /usr/bin/irb:12:in `<main>'

You can save your `Struct.new` returned `class` to a variable and you can use that will be always the same `class`.

irb(main):004:0> Id = Struct.new :id
#<Class:0x00000002c35b20>
irb(main):005:0> class Test2 < Id; end
nil
irb(main):006:0> class Test2 < Id; end
nil

or You can use `Struct.new` block style instead of `class` keyword it will only give `warning: already initialized constant Test3` when you reload your file.

irb(main):023:0> Test3 = Struct.new(:id) do
                     def my_methods
                     "this is a method"
                     end
                   end

Problem

Suppose there's the following class ``` # derp.rb class Derp < Struct.new :id end ``` When I `load "./derp.rb"` twice the program fails with `TypeError: superclass mismatch for class Derp`. Ok, this could be managed with `require`. But how can I reload such classes for each test run with Spork? `require` obviously won't work cause it caches the loaded files.

Original source