Getting simplecov to work with minitest's rake task

[zenspider]

I've always hated how rake runs tests... it's SO broken. I've been running my own test task via hoe for a very long time and recentlyish ported it over to minitest (see the file here)... it runs in a different manner and as such, the recipe in the simplecov readme doesn't work...

I'm left wondering if this is related to / a variant of #1023 or not...

Here's what I've figured out so far:

with the following recipe at the top of my test:

if ENV['COV'] then
  require 'simplecov'
  SimpleCov.start
end

a manual run works fine:

%  ruby -I... -w test/test_debride.rb

but what the minitest rake task is doing does not:

% ruby -I... -w -e 'require "minitest/autorun"; require "test/test_debride.rb"' -- 

Instead, it runs the report BEFORE the tests start.

If I remove the recipe at the top of the file and manually modify the rake task command:

% ruby -I... -w -e 'require "simplecov"; SimpleCov.start; require "minitest/autorun"; require "test/test_debride.rb"' -- 

then it works again.

AFAICT... this has something to do with the way you're checking for minitest (the guess methods?) or hooking at_exit ... having the minitest/autorun inclusion might be messing it up. We can either try to figure out how to make simplecov happy no matter how tests are run (minitest/autorun before or after), or I can chalk this up to my rake task doing too much too soon and build in support for simplecov to the task itself.

What do you think?

[copiousfreetime]

Finding this in 2024 and the following seems to be working for me now, not sure what update I did with which gem, but I had 99% test coverage and then it went to 40% without any of my code changes, just gem dependencies.

Ended up with this as my task:

  Minitest::TestTask.create(:coverage) do |t|
    t.test_prelude = 'require "simplecov"; SimpleCov.start;'
    t.libs << "spec"
    t.warning = true
    t.test_globs = "{test,spec}/**/{test_*,*_spec}.rb"
  end

Resulting rake coverage:cmd

ruby -Ilib:test:.:spec -w -e 'require "simplecov"; SimpleCov.start;; require "minitest/autorun"; require "spec/paths_spec.rb"; require "spec/timed_metric_spec.rb"; require "spec/mutex_stats_spec.rb"; require "spec/metric_spec.rb"; require "spec/value_metric_spec.rb"; require "spec/interval_spec.rb"; require "spec/stats_spec.rb"; require "spec/initialize_spec.rb"; require "spec/hitimes_spec.rb"; require "spec/timed_value_metric_spec.rb"; require "spec/version_spec.rb"' --

[zenspider]

@copiousfreetime: Agreed... This is what hoe does these days w/ the test_prelude, but you might want to change yours a bit to possibly fix the test coverage numbers:

t.test_prelude = %(require "simplecov"; SimpleCov.start { add_filter %p }) % [cov_filter]

where cov_filter defaults to %w[tmp test].

I've given up on the maintainers tending to their issues so I'm closing this to get it off MY radar.