August 15, 2017

Understanding the Internal Mechanics of StreamData, an Elixir Property Testing Library

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Understanding the Internal Mechanics of StreamData, an Elixir Property Testing Library

Source: andrealeopardi.com

Andrea Leopardi offers a deep-dive into StreamData, a property testing library for Elixir he developed, which generates random test data to uncover bugs in software. Property-based testing, exemplified by QuickCheck in Haskell, has been adapted for several languages, including Erlang, Scala, and now Elixir with StreamData. Unlike traditional expository posts, Leopardi delves into StreamData's complex innards, from data generation using infinite streams, randomness reproducibility, and generator structuring, to specifics like random seed splitting. A significant focus lies on the concept and execution of shrinking, a method of reducing noisy failure-inducing data to its simplest, most informative form, contrasting with other languages' strategic approaches. The library's generator design structure facilitates seamless generation and shrinking, resulting in more efficient testing. The article concludes by acknowledging the influence of other property testing tools and the author's own learnings from creating StreamData. Leopardi expresses gratitude towards the contributors to similar projects like QuickCheck and test.check, which guided StreamData's development.

Managing Persistent Connections Using gen_statem in Elixir

Andrea Leopardi explores how to maintain persistent connections to external services using gen_statem, a behavior in Erlang and Elixir for building state machine processes. By leveraging gen_statem, processes can stay connected to the external services and handle events such as connection failures and client requests more efficiently.

Apr 14, 2019

Using Elixir's Registry for Process Pooling

Andrea Leopardi explores process pooling strategies in Elixir using Elixir's built-in Registry. The post discusses the differences between checkout pools and routing pools, provides code examples, and explains how to implement different routing strategies within a pool.

Apr 25, 2020

Combining Example-Based and Property-Based Testing in Elixir

Andrea Leopardi believes that example-based tests and property-based tests are like good friends. By combining the ability of property-based testing to test a wide range of input data with practical example-based tests, you can ensure that your code behaves as expected on real inputs and discover unhandled corner cases. Leopardi shares an example of how this technique can be used and emphasizes the effectiveness and practicality of this approach.

Jan 09, 2022