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.
Sage Fulcher
Hey I'm Sage! Im a Boston area software engineer who grew up in South Florida. Ive worked at a ton of cool places like a telehealth kidney care startup that took part in a billion dollar merger (Cricket health/Interwell health), a boutique design agency where I got to work on a ton of exciting startups including a photography education app, a collegiate Esports league and more (Philosophie), a data analytics as a service startup in Cambridge (MA) as well as at Phillips and MIT Lincoln Lab where I designed and developed novel network security visualizations and analytics. I've been writing code and furiously devoted to using computers to make people’s lives easier for about 17 years. My degree is in making computers make pretty lights and sounds. Outside of work I love hip hop, the Celtics, professional wrestling, magic the gathering, photography, drumming, and guitars (both making and playing them)
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.
Richard McSorley
Full-Stack Software Engineer with 8+ years building high-performance applications for enterprise clients. Shipped production systems at Walmart (4,000+ stores), Cigna (20M+ users), and Arkansas Blue Cross. 5 patents in retail/supply chain tech. Currently focused on AI integrations, automation tools, and TypeScript-first architectures.
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.
Jaime Orts-Caroff
I'm a Senior Android developer, open to work in various fields
Matthew Butler
Systems Development Engineer @ Amazon Web Services
Meïr Ankri
Full-stack developer specializing in React / Next.js / Node.js with 6+ years of experience. I've worked across various sectors including automotive (Reezocar/Société Générale), healthcare (Medical Link SaaS), and e-commerce (Glasman). I build web apps end-to-end, from architecture to production, with a focus on scalability, performance, and code quality. I also mentor junior developers and contribute to technical decisions and code reviews.
PawelPloszaj
I'm fronted developer with 10+ years of experience with big projects. I have small backend background too
Taufan
I’m a product-focused engineer and tech leader who builds scalable systems and turns ideas into production-ready platforms.
Over the past years, I’ve worked across startups and fast-moving teams, leading backend architecture, improving system reliability, and shipping products used by thousands of users. My strength is not just writing code — but connecting product vision, technical execution, and business impact.
Omar Faruk
As a Product Engineer at Klasio, I contributed to end-to-end product development, focusing on scalability, performance, and user experience.
My work spanned building and refining core features, developing dynamic website templates, integrating secure and reliable payment gateways, and optimizing the overall system architecture.
I played a key role in creating a scalable and maintainable platform to support educators and learners globally.
I'm enthusiastic about embracing new challenges and making meaningful contributions.
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.