params are strings IRL, integers in test

This can be duplicated on edge Rails:

class TestsController < ApplicationController
  def show
    render :text => params[:id].class.to_s
  end
end

require 'test_helper'

class TestsControllerTest < ActionController::TestCase
  test "id param is a Fixnum" do
    get :show, :id => 42
    assert_equal 'Fixnum', response.body
  end
end

I definitely think this should be fixed. Since a controller will always receive all parameters as strings in real life, I think all parameters passed from tests should be converted to strings for consistency.

Patch welcome.

This has come up before: #2984 Warn when parameters to functional test requests have improper values