Cursor
testing
Cursor-Generated Unit Tests Failing Immediately
You asked Cursor to generate unit tests for your code, but the tests fail immediately when you run them. The failures range from import/module resolution errors and incorrect assertions to tests that reference functions or methods that don't exist in your codebase. The tests look plausible but don't actually test your real implementation.
AI-generated tests are one of the most requested features, but they're also one of the most error-prone. Cursor generates tests based on its understanding of your code, but may hallucinate function signatures, assume different export patterns, or use the wrong testing framework syntax. The tests compile but don't accurately reflect your actual code.
Running these failing tests wastes time debugging test code instead of production code, and if you force them to pass by adjusting the tests, you end up with tests that don't actually verify correct behavior.
Error Messages You Might See
Cannot find module '../utils/helpers' from 'tests/helpers.test.ts'
TypeError: functionName is not a function
Expected: 200, Received: undefined
ReferenceError: describe is not defined
Error: No test suite found in file
TS2305: Module '"../src/service"' has no exported member 'processData'
Common Causes
- Wrong import paths — Cursor generates imports like
import { func } from '../utils'when the actual path isimport { func } from '../lib/utils' - Hallucinated function signatures — Tests call functions with parameters that don't match the actual implementation (wrong parameter count, types, or names)
- Wrong testing framework syntax — Cursor generated Jest syntax but the project uses Vitest, or generated Mocha syntax for a Jest project
- Missing test configuration — Jest/Vitest config doesn't have the necessary transformers, module mappers, or setup files for the generated tests to run
- Incorrect assertion values — Tests assert expected values that don't match what the function actually returns, based on the AI's assumption of behavior
- Private or unexported functions tested directly — Tests try to import and test internal functions that aren't exported from the module
How to Fix It
- Verify import paths match your project structure — Check every import statement in the generated tests against your actual file tree. Fix paths to match the real module locations
- Cross-reference function signatures — Open the source file being tested alongside the test file. Verify that every function call in the test matches the actual parameters, return types, and export names
- Check your test framework configuration — Verify your jest.config.js or vitest.config.ts matches what the tests expect. Ensure TypeScript, JSX, and module alias transformations are configured
- Run tests one at a time — Use
jest --testPathPattern=filenameorvitest run filenameto run one test file at a time and fix issues incrementally - Treat generated tests as scaffolding — Don't expect AI tests to be correct out of the box. Use them as a starting structure and manually verify/fix each assertion against the actual code behavior
- Add your testing patterns to .cursorrules — Specify your test framework, file naming conventions, and import patterns so Cursor generates compatible tests
Real developers can help you.
Jared Hasson
Full time lead founding dev at a cyber security saas startup, with 10 yoe and a bachelor's in CS. Building & debugging software products is what I've spent my time on for forever
Franck Plazanet
I am a Strategic Engineering Leader with over 8 years of experience building high-availability enterprise systems and scaling high-performing technical teams. My focus is on bridging the gap between complex technology and business growth.
Core Expertise:
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I thrive on "out-of-the-box" thinking to solve complex technical bottlenecks and am always looking for ways to use automation to improve business productivity.
BurnHavoc
Been around fixing other peoples code for 20 years.
Vlad Temian
15+ years shipping production infrastructure for startups. Former CTO at qed.builders (acquired by The Sandbox).
Cursor ambassador and agentic tooling builder.
I've scaled systems, automated deployments, and built observability tools for AI coding workflows. I specialize in taking vibe-coded apps from broken prototype to production-ready: fixing Supabase auth/RLS, Stripe integrations, deployment pipelines, and cleaning up AI-generated spaghetti.
I build tools in this space (agentprobe, claudebin, micode) and understand both sides: how AI generates code and why it breaks.
https://blog.vtemian.com/
Dor Yaloz
SW engineer with 6+ years of experience,
I worked with React/Node/Python
did projects with React+Capacitor.js for ios
Supabase expert
Tejas Chokhawala
Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript.
Focused on performance, clean architecture and shipping fast.
Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools.
ISHANTDEEP SINGH
Senior Software Engineer with 7+ years of experience in React, JavaScript, TypeScript, Next.js, and Node.js. I’ve also worked as a tech lead for startups, owning end-to-end technical execution including architecture, development, scaling, and delivery. I bring a strong mix of hands-on coding, product thinking, and technical leadership, and I’m comfortable building products from scratch as well as improving and scaling existing systems.
AUXLE
I am a Full Stack Developer experienced in building Websites, Web apps and Cross Platform Mobile Apps for Startups and Companies.
Matthew Jordan
I've been working at a large software company named Kainos for 2 years, and mainly specialise in Platform Engineering. I regularly enjoy working on software products outside of work, and I'm a huge fan of game development using Unity. I personally enjoy Python & C# in my spare time, but I also specialise in multiple different platform-related technologies from my day job.
Rudra Bhikadiya
I build and fix web apps across Next.js, Node.js, and DBs.
Comfortable jumping into messy code, broken APIs, and mysterious bugs.
If your project works in theory but not in reality, I help close that gap.
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
Should I trust AI-generated test assertions?
No. Always verify assertions manually. AI tests often assert what the code 'should' do based on function names, not what it actually does. Run the function manually and compare the output to the test's expected value.
How do I get Cursor to generate better tests?
Provide context by opening the source file in a Cursor tab, specify your test framework in the prompt ('write Jest tests with TypeScript'), and include an example test file from your project so Cursor matches the style.