Claude Code
testing
Integration Tests Fail Randomly Due to Shared State
Your integration tests pass when run individually but fail randomly when run as a suite. The failures are non-deterministic: different tests fail on different runs, tests that were passing start failing after adding new tests, and the CI pipeline has become unreliable with intermittent failures.
Flaky tests are a serious productivity drain. Developers lose trust in the test suite, start ignoring failures ('it's just a flaky test'), and eventually stop running tests altogether. Real bugs hide behind the noise of flaky failures.
Claude Code generates integration tests that work in isolation but share database state, use hardcoded ports, rely on test ordering, or have timing dependencies that cause failures when tests run in parallel or in different orders.
Error Messages You Might See
Error: listen EADDRINUSE :::3000
Expected 1 row but found 3 rows
Timeout: Async callback was not invoked within 5000ms
Error: relation 'users' already exists
1 test passed, 1 test failed (different test each run)
Common Causes
- Shared database state between tests — One test creates data that another test doesn't expect, or a test deletes data another test needs
- No database cleanup between tests — Tests don't reset the database to a known state before or after running
- Hardcoded ports — Multiple test files try to start servers on the same port, causing EADDRINUSE errors
- Test order dependency — Tests rely on being run in a specific order because earlier tests set up state that later tests need
- Timing-dependent assertions — Tests use setTimeout or fixed delays that are long enough locally but too short in CI
How to Fix It
- Use database transactions for isolation — Wrap each test in a transaction that rolls back after the test completes, ensuring clean state
- Create fresh state in each test — Use beforeEach to set up exactly the data each test needs. Never rely on state from other tests
- Use random ports — Start test servers on port 0 (OS assigns a random available port) to avoid conflicts
- Randomize test order — Configure your test runner to randomize test execution order to expose hidden dependencies
- Replace timeouts with polling — Instead of await sleep(1000), poll for the expected condition with a timeout: await waitFor(() => expect(result).toBe(expected))
- Use testcontainers — Spin up isolated database instances per test suite using Docker containers
Real developers can help you.
Prakash Prajapati
I’m a Senior Python Developer specializing in building secure, scalable, and highly available systems. I work primarily with Python, Django, FastAPI, Docker, PostgreSQL, and modern AI tooling such as PydanticAI, focusing on clean architecture, strong design principles, and reliable DevOps practices. I enjoy solving complex engineering problems and designing systems that are maintainable, resilient, and built to scale.
David Olverson
Solo dev shipping production apps with AI-assisted development. I specialize in rescuing broken Lovable/Bolt/Cursor builds and taking them to production. 10+ apps shipped including SaaS CRMs, gaming platforms, real estate tools, and Discord bots. Stack: Next.js 16, TypeScript, Tailwind CSS, FastAPI, PostgreSQL, Prisma. I use Claude Code with 50+ custom skills for rapid delivery. Average turnaround: 2-4 weeks from broken prototype to production.
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:
🚀 Leadership: Managing and coaching teams of 15+ engineers, fostering a culture of accountability and continuous improvement.
🏗️ Architecture: Enterprise Core Systems, Multi-system Integration (ERP/API/ETL), and Core Database Structure.
☁️ Cloud & Scale: AWS Expert; architected systems handling 10B+ monthly requests and managing 100k+ SKUs.
📈 Business Impact: Aligning tech strategy with P&L goals to drive $70k+ in monthly recurring revenue.
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.
Yovel Cohen
I got a lot of experience in building Long-horizon AI Agents in production, Backend apps that scale to millions of users and frontend knowledge as well.
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
Jen Jacobsen
I’m a Full-Stack Developer with over 10 years of experience building modern web and mobile applications. I enjoy working across the full product lifecycle — turning ideas into real, well-built products that are intuitive for users and scalable for businesses.
I particularly enjoy building mobile apps, modern web platforms, and solving complex technical problems in a way that keeps systems clean, reliable, and easy to maintain.
Caio Rodrigues
I'm a full-stack developer focused on building practical and scalable web applications. My main experience is with **React, TypeScript, and modern frontend architectures**, where I prioritize clean code, component reusability, and maintainable project structures.
I have strong experience working with **dynamic forms, state management (Redux / React Hook Form), and complex data-driven interfaces**. I enjoy solving real-world problems by turning ideas into reliable software that companies can actually use in their daily operations.
Beyond coding, I care about **software quality and architecture**, following best practices for componentization, code organization, and performance optimization.
I'm also comfortable working across the stack when needed, integrating APIs, handling business logic, and helping transform prototypes into production-ready systems.
My goal is always to deliver solutions that are **simple, efficient, and genuinely useful for the people using them.**
Matthew Butler
Systems Development Engineer @ Amazon Web Services
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
Matt Butler
Software Engineer @ AWS
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
How do I isolate database state between integration tests?
The best approach is to wrap each test in a database transaction and roll it back after the test. Alternatively, use TRUNCATE on all tables in beforeEach, or use testcontainers to spin up a fresh database per test suite.
Why do my tests pass locally but fail in CI?
CI environments are typically slower and have less CPU. Timing-dependent tests that pass locally may timeout in CI. Replace fixed delays with polling/waitFor patterns and increase timeouts for CI environments.