andrewrk/node-whynoteq

whynoteq is a small JavaScript utility that tells you exactly why two values are not equal. It's designed for developers writing automated tests who need to compare complex data structures and figure out, at a glance, what's different. When you write code, you often need to check if two objects or arrays contain the same data. JavaScript can tell you they're different, but it doesn't tell you where the difference is. This library fills that gap. Instead of just saying "these don't match," it gives you a specific path to the problem, like pointing out that index 2 in an array contains a 1 instead of a 3. This is most useful for anyone doing test-driven development. If you have a test that compares a large chunk of output data against what you expected, and the test fails, this tool immediately pinpoints the mismatch. You can pass in a custom error message, and the library will append its detailed finding to that message before throwing an error. It handles nested objects and arrays, drilling down to the exact property or array position that differs. One notable detail is that the library treats undefined properties the same as properties that don't exist at all. This means that an object with a key set to undefined and an object missing that key entirely are considered equal, which aligns with common JavaScript behavior but might surprise you if you expect strict structural matching. The README is sparse and does not go into detail about how the project is built or maintained, but the code examples are clear enough to show exactly what the tool does.