You've probably tried this: paste your code into ChatGPT, ask it to write tests, copy the output into your project... and watch it fail. Wrong imports. Broken mocks. Assertions that test nothing. You spend the next hour debugging tests instead of building features.
ChatGPT is a general-purpose AI. It's great at explaining code and writing first drafts. But it has no access to your file system, can't run tests, can't see errors, and can't iterate. It generates tests in a vacuum and hopes for the best.
ShipTested takes a fundamentally different approach. It reads your actual project structure, understands your imports and dependencies, generates tests, runs them in a sandbox, and when they fail, it reads the errors, fixes the code, and re-runs. Automatically. Until they pass.
| Feature | ShipTested | ChatGPT |
|---|---|---|
| Generates test code | ||
| Understands your project structure | Auto-detects framework, imports, aliases | You explain manually each time |
| Runs the tests | In an isolated sandbox | You copy-paste and run yourself |
| Fixes failing tests | Automatic iteration loop | You paste errors back, ask again |
| Knows your dependencies | Reads package.json | Guesses or hallucinates packages |
| Correct import paths | Resolves from your file tree | Often wrong, especially with aliases |
| Mocking strategy | Matches your existing patterns | Generic mocks, often incorrect |
| Coverage report | Per-file and aggregate | |
| GitHub integration | Auto-generate tests on PR | |
| Batch processing | Test entire project at once | One file at a time, manually |
| Consistency | Same approach every time | Different output each conversation |
| Cost | Free tier + $15/mo Pro | $20/mo (ChatGPT Plus) |
The most common failure when ChatGPT writes tests: wrong import paths. Your project uses @/lib/utils as an alias for src/lib/utils.ts. ChatGPT doesn't know that. It guesses ./utils, ../lib/utils, or invents a path that doesn't exist.
ShipTested reads your tsconfig.json, resolves your path aliases, and generates imports that match your actual project structure. If it still gets something wrong, the sandbox catches it and the AI fixes it in the next iteration.
ChatGPT generates generic mocks. jest.mock('axios'). But your project doesn't use axios. It uses a custom api.ts wrapper around fetch. Or it uses Supabase. Or tRPC. ChatGPT doesn't know because it can't see your codebase.
ShipTested analyzes your imports, identifies what needs mocking, and checks your existing test files for mocking patterns. If your repo already uses vi.mock with specific patterns, ShipTested follows the same conventions.
The AI generates, runs, reads errors, fixes, and re-runs in a sandbox, without you touching anything. Most files pass within 2-3 iterations.
ChatGPT is still great for learning about testing patterns, understanding what a test should do, or getting a rough starting point for a single function. If you need to understand testing concepts, ChatGPT is a solid teacher.
When you need tests that actually run. When you have a real project with dozens of files and zero coverage. When you're tired of the copy-paste-fix-paste loop. When you want to go from 0% to 80% coverage in minutes, not days.
Free tier. 3 files/month, no credit card required.