Add helper methods for starting/stopping trace

[yuki24]

Given the issue #65, it seems like there is some general interest in a simpler interface for using traces. The code in this PR is the code I use to test https://toprubycompanies.info in CI, and it's been working very well.

With the new interfaces introduced by this PR, using Playwright's trace is as simple as:

class ApplicationSystemTestCase < ActionDispatch::SystemTestCase
  driven_by :playwright

  setup do
    page.driver.start_tracing(title: method_name) if retrying?
  end

  def before_teardown
    if retrying?
      page.driver.stop_tracing(path: "./tmp/playwright/traces/#{method_name}.zip"))
    end
  ensure
    super
  end

  def retrying?
    # Determine whether the run is a retry...
  end
end

With RSpec, it could look like:

around :example do |example|
  if should_trace?
    page.driver.trace path: "./tmp/playwright/traces/#{example.metadata[:full_description]}.zip" do
      example.run
    end
  end
end

def should_trace?
  # Somehow determine whether the run should be traced.
end

[YusukeIwaki]

Thank you for your contribution.

it seems like there is some general interest in a simpler interface for using traces.

After several investigation, I completely agree with this.

[YusukeIwaki]

@yuki24 I prefer the method name with_tracing for this. Do you have any ideas about this?

[yuki24]

I think the name with implies that the word tracing is a thing, rather than being an action. For example, all the methods prefixed with with_ in Rails follow the form of with_thing, rather than with_doing:

Whereas other methods, such as #draw, #transaction, and #freeze_time, all trigger an explicit action under the hood, and the execution in the block is in effect of the action you would like to take. I believe this case is closer to the latter.

So based on this assessment, I would think that the name #trace is more intuitive than #with_tracing.

With that all said, this is ultimately your call. Let me know what you think.

[YusukeIwaki]

Thank you for your kind advices.
I didn't know well about the Rails existing method names and its rules, and your advices really helped me.

Let's keep the method name 'with_trace' here.

[yuki24]

Thank you!