stackprof VS Ruby Tests Profiling Toolbox

stackprof can be used alone/by itself to generate flamegraphs for arbitrary Ruby code.

I’d use something like stackprof ( https://github.com/tmm1/stackprof ) to see where the time is going. If you already have suspicions you can use it to get information about a specific method / few lines of Ruby but there’s also a rack middleware.

stackprof

Other profilers, such as stackprof, trace everything that’s happening by line. These types of profilers usually need some instrumentation to be configured, as shown below:

Either https://github.com/tmm1/stackprof for cpu or https://github.com/SamSaffron/memory_profiler for memory. In practice profiling and removing allocations also gives a large perf boost.

At first, I tried to benchmark the method using the benchmark library. (The profiler uses stackprof)

gem "test-prof" - https://github.com/test-prof/test-prof | Toolkit for inspecting and optimising your test-suite, a must-have.

You might be able to do something with https://test-prof.evilmartians.io, but I'm not sure it has anything specific to fixtures out of the box. Maybe using the event profiler on sql.active_record events would be close enough. In the limit, you could wire together your own ActiveSupport::Notifications.instrument around the relevant blocks + an ActiveSupport::Notifications.subscribe to that event so as to log the relevant information. Docs: https://api.rubyonrails.org/classes/ActiveSupport/Notifications.html

To have a better vision of what objects are created in our spec file we can use test-prof, a powerful gem that provides a collection of different tools to analyse your test suite performance. One of this tool is really useful to identify a factory cascade, let’s introduce factory profiler.

TestProf can be used to get flamegraphs for Ruby test suites.

Rspec has spec_helper.rb.

I also love the test-prof documentation, there's a lot of good ideas on how to improve test performance.