Paste a diff to get a fast, senior-engineer-style pass that prioritizes what actually matters — correctness bugs, regressions, security issues, missing tests, and maintainability risks — over style nitpicks. Each finding comes with severity, evidence pulled directly from the diff, and a concrete suggested change, making it a solid gate to run before opening a pull request.
Takes a single function plus its test framework (or "unknown" if you're not sure) and writes a practical test suite covering the main happy path, boundary cases, invalid inputs, and expected failure modes. It matches the project's existing test style when one is visible in the pasted context, and states any assumptions it made before showing the actual test code.
Feed in a suspicious snippet along with the error message and expected behavior, and get back a ranked list of likely bugs instead of a vague hunch. Each finding names the observable symptom, the probable root cause, the exact lines or functions responsible, and a concrete fix to apply. When the pasted context isn't enough to be confident, it says exactly what extra detail is missing instead of guessing at a diagnosis.
Paste any unfamiliar snippet and get a statement-by-statement walkthrough instead of a single high-level summary. Each line is explained in plain language: what it does, why it's there, and any assumption it quietly depends on, with jargon defined inline as it comes up. Built for developers who already know how to code but are new to this particular codebase, library, or language idiom.