Property-Based Testing: Writing Symmetric Properties with PropEr

Traditional unit tests often miss edge cases in complex data transformations like encoding, decoding, serialization, and parsing. This text-based course guides you through property-based testing, focusing on symmetric properties to ensure your data remains intact across reversible operations. You will transition from writing basic example-based tests to constructing powerful, automated properties that validate your code against thousands of inputs. By understanding how to structure round-trip assertions, you will catch subtle bugs, handle edge cases automatically, and improve the overall reliability of your software. What you'll learn: Understand the foundational concepts of property-based testing and how it differs from unit testing; Define symmetric properties to validate reversible sequences like serialization and deserialization; Configure generators in PropEr to produce diverse and realistic test data; Analyze failing test cases using shrinking strategies to quickly isolate root causes; Practice writing custom properties for complex data structures; Integrate property-based tests into modern development workflows for continuous validation. This course starts with essential terminology and the core mechanics of property-based testing before moving into practical coding exercises and patterns. You will read clear explanations, study structured code snippets, and solve written exercises designed to build your confidence step-by-step. This course is designed for software developers and QA engineers who want to elevate their testing practices; no prior experience with property-based testing is required. Start reading today to build more resilient software through automated, symmetric testing.