Feature #13838: Add the ability to detect Coverage status

• Status: Closed
• Assignee: -
• Target version: -

[yui-knk (Kaneko Yuichiro)]

Description

I want to detect current status of Coverage, which is enabled or not.
Now we can detect status only trying Coverage.peek_result or Coverage.result and catch RuntimeError.
Attached patch enable us to detect status without any exceptions.

Why

My daily work is developing a web application with Ruby.

I am using Coverage.peek_result to record coverage information on a per-request basis.

When recording coverage information, I want to start Coverage on a part of production servers,
because Coverage tool may have some overhead.

In this case, the code of my program looks like

# Implement as Rack middleware
class CoverageMiddleware
  def initialize(app)
    @app = app
  end 

  def call(env)
    # To ensure return response, rescue exceptions
    before = Coverage.peek_result rescue nil
    res = @app.call(env)
    after = Coverage.peek_result rescue nil

    if (before && after)
      write_file(diff(before, after))
    end

    return res
  end
end

Example

By using `Coverage.enabled?, I can

class CoverageMiddleware
  def initialize(app)
    @app = app
  end 

  def call(env)
    if Coverage.enabled?
      before = Coverage.peek_result
      res = @app.call(env)
      after = Coverage.peek_result

      write_file(diff(before, after))
    else
      res = @app.call(env)
    end

    return res
  end
end

[yui-knk (Kaneko Yuichiro)]

• Tracker changed from Bug to Feature
• Backport deleted (2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN)

[mame (Yusuke Endoh)]

• Status changed from Open to Closed

I think this is a duplicate of #13667. Let us discuss this issue in that ticket. Thank you!

[yui-knk (Kaneko Yuichiro)]

Sorry I overlooked the issue :)