mock_belongs_to.rb

class FakeModel
  DataArray = []

  class << self

    def arel_table; end

    def relation_delegate_class(_arg)
      MockRelationDelegate
    end

    def all(*_args)
      self
    end
    alias unscoped all
    alias extending! all
    alias merge all
    alias limit all

    def eager_loading?
      true
    end

    def connection
      self
    end

    def table_name
      ""
    end

    def primary_key
      :id
    end

    def schema_cache
      self
    end

    def columns_hash(*_args)
      HashWithIndifferentAccess.new(id: :id)
    end

    def substitute_at(*_args)
      self
    end

    def bind_values
      @bind_values ||= []
    end

    attr_writer :bind_values

    def where(*_args)
      self
    end

    def to_a
      bind = bind_values.first
      DataArray.select { |f| f[bind.first] == bind.second }.map { |f| make(f) }
    end

  end

  class MockRelationDelegate

    def initialize(*_args); end

    def merge!(arg)
      arg
    end

  end
end