Use Minitest one-line pattern matching assert in Ruby

Thu, 27 Aug 2026 08:50:00 +0000

If you haven’t written Ruby tests using Minitest in a while, you might have missed the addition of the assert_pattern assertion (available in Ruby 3.0 and higher). Right now, it’s my absolute favorite assertion when I need to validate a complex object-like an array or a hash-in a single go. Of course, there is one limitation when checking hashes: keys can only be symbols. So if you want to validate JSON, you’ll need to transform its keys from strings to symbols first.

Minitest on Artem Yegorov

Use Minitest one-line pattern matching assert in Ruby