Efficient Data Shrinking in PropEr with LETSHRINK

When property-based tests fail, analyzing massive, complex data structures can feel like finding a needle in a haystack. Understanding how to automatically reduce these failures to their simplest form is the key to rapid debugging. This text-only course guides you through the foundational concepts of property-based testing and teaches you how to implement efficient data shrinking. You will learn to write cleaner, more maintainable test suites that pinpoint the exact cause of code failures. What you'll learn: Understand the fundamental principles of property-based testing and data shrinking; Configure the PropEr framework and set up your initial testing environment; Apply the ?LETSHRINK macro to simplify large, nested data structures automatically; Isolate failing subsets of data to diagnose bugs with minimal manual effort; Integrate modern testing workflows and clean code practices into your test suites; Analyze shrink paths to understand how PropEr reduces complex test inputs. You will start with core definitions and basic setup before moving on to practical code examples that demonstrate how to control the shrinking process. Through step-by-step written explanations, you will transition from basic property tests to advanced custom shrinking strategies. This course is designed for beginners new to property-based testing or those looking to improve their debugging workflow. No advanced testing experience is required. Start reading today to make your test failures instantly readable and actionable.