From: mame@... Date: 2017-09-02T14:11:54+00:00 Subject: [ruby-core:82635] [Ruby trunk Feature#13667][Feedback] Add Coverage.running? to quickly check if Coverage is enabled. Issue #13667 has been updated by mame (Yusuke Endoh). Status changed from Closed to Feedback I applied the patch proposed. After that, however, I'm now considering reverting it. I noticed that this feature may be dangerous. By using this, we can easily write a program that changes its behavior only under coverage measurement. It brings difficulties to testing with coverage measurement. I don't see such a bad program released into the wild. Could you elaborate your use case that beats the disadvantage? If any, I will remain the feature, but otherwise, I will revert it. ---------------------------------------- Feature #13667: Add Coverage.running? to quickly check if Coverage is enabled. https://bugs.ruby-lang.org/issues/13667#change-66462 * Author: burke (Burke Libbey) * Status: Feedback * Priority: Normal * Assignee: mame (Yusuke Endoh) * Target version: ---------------------------------------- Since we can't `RubyVM::InstructionSequence#to_binary` when `Coverage` is running, it is useful to be able to ask ruby if coverage is active. This is possible with `Coverage.peek_result`, but not efficient, since it involves quite a bit of data copying. I've used the private symbol `rb_get_coverages` in [bootsnap](https://github.com/Shopify/bootsnap/pull/63) for now but this feels worth exposing publicly. ``` > Benchmark.realtime { 100.times{ Coverage.peek_result } } => 1.3659249999909662 > Benchmark.realtime { 100.times{ Bootsnap::CompileCache::Native.coverage_running? } } => 5.099998088553548e-05 ``` Example usage: ``` class RubyVM::InstructionSequence def load_iseq(path) return nil if defined?(Coverage) && Coverage.running? # ... end end ``` ---Files-------------------------------- 0001-Add-Coverage.enabled-to-quickly-check-if-coverage-is.patch (1.97 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: