server_rendering_test.rb

# frozen_string_literal: true

require "test_helper"

class NullRenderer
  def initialize(options)
    # in this case, options is actually a string (just for testing)
    @name = options
  end

  def render(component_name, props, prerender_options)
    "#{@name} rendered #{component_name} with #{props} and #{prerender_options}"
  end
end

class ReactServerRenderingTest < ActiveSupport::TestCase
  setup do
    @previous_renderer = React::ServerRendering.renderer
    @previous_options = React::ServerRendering.renderer_options
    React::ServerRendering.renderer_options = "TEST"
    React::ServerRendering.renderer = NullRenderer
    React::ServerRendering.reset_pool
  end

  teardown do
    React::ServerRendering.renderer = @previous_renderer
    React::ServerRendering.renderer_options = @previous_options
    React::ServerRendering.reset_pool
  end

  test ".render returns a rendered string" do
    props = { "props" => true }
    result = React::ServerRendering.render("MyComponent", props, "prerender-opts")

    assert_equal("TEST rendered MyComponent with #{props} and prerender-opts", result)
  end

  test ".reset_pool forgets old renderers" do # rubocop:disable Minitest/MultipleAssertions
    # At first, they use the first options:
    assert_match(/^TEST/, React::ServerRendering.render(nil, nil, nil))
    assert_match(/^TEST/, React::ServerRendering.render(nil, nil, nil))

    # Then change the init options and clear the pool:
    React::ServerRendering.renderer_options = "DIFFERENT"
    React::ServerRendering.reset_pool
    # New renderers are created with the new init options:
    assert_match(/^DIFFERENT/, React::ServerRendering.render(nil, nil, nil))
    assert_match(/^DIFFERENT/, React::ServerRendering.render(nil, nil, nil))
  end
end