Quick answer
Qodo (rebranded from Codium) is an AI tool that writes tests for your existing code, reviews pull requests, and tracks coverage over time. It works inside your IDE and CI pipeline rather than replacing your editor. The tests it generates are decent at catching obvious regressions and edge cases you forgot, but weak at catching bugs that require understanding business intent — which is true of basically every AI test generator, not just this one.
Most AI coding tools are optimized for writing code fast. Qodo bets on a different problem: nobody writes enough tests, and the tests people do write are often shallow. So instead of generating features, it generates the boring-but-necessary stuff around them.
What Qodo actually does
Point Qodo at a function, a file, or a whole pull request, and it generates unit tests aimed at your existing test framework — Jest, PyTest, JUnit, and others. It also has a PR review mode that flags risky changes, missing test coverage, and possible bugs before a human reviewer looks at it.
- Test generation for individual functions or entire files, matching your existing test style
- PR-level review that flags uncovered code paths and suspicious diffs
- Coverage tracking across a repo over time, not just a single run
- IDE extensions for VS Code and JetBrains, plus a CI integration for automated PR checks
Are the tests actually good?
We ran it against a mid-sized TypeScript backend with existing test coverage around 40%. The tests it generated for pure functions — string parsing, data transforms, validation logic — were genuinely useful. It caught a couple of edge cases (empty arrays, null fields) that our own test suite had missed.
Where it struggled was anything involving side effects or business logic that depends on context the code itself doesn't express. It will happily write a test that asserts a function returns what the function currently returns, which is not the same as asserting it returns what it should return. That distinction matters, and no AI tool has fully solved it yet.
How does this compare to writing tests yourself?
It is faster, and it is a good first draft. It is not a substitute for a developer who understands what the function is supposed to do. Think of it as filling in the tedious 70% — boundary conditions, type mismatches, obvious null checks — so a human can spend their time on the 30% that requires actual judgment.
Where it fits next to code review tools
Qodo's PR review feature overlaps with tools like CodeRabbit, but the emphasis is different. CodeRabbit reads more like a thorough human reviewer commenting on style and logic. Qodo leans harder into "is this covered by a test, and if not, here's one" — which is a narrower but genuinely useful lane.
Generated tests are only as good as the assumption that your current code is correct. If a function has a bug, an AI test generator will often just write a test that confirms the bug.
Who should use Qodo?
- Teams with low test coverage that need a fast way to raise the floor
- Solo developers who skip tests because writing them feels like a chore
- Engineering orgs already using AI PR review and wanting coverage tracking bundled in
It is a weaker fit if your codebase is small and your team already writes disciplined tests — the marginal value drops fast once your coverage is already good.
Related reading
Bottom line
Qodo is genuinely useful for raising a codebase's test coverage floor quickly, especially on pure, low-context functions. Just don't mistake "has tests" for "is correct" — those are different claims, and Qodo can only really help with the first one.
