Claude Code Says 'All Tests Pass' but CI Goes Red — Designing Around Exit Code Pitfalls
Locally, Claude Code reports 'all tests pass.' You push it, and GitHub Actions turns red within minutes. The root cause is usually not Claude Code itself but how the shell and the test runner interpret exit codes. Here is a practical, experience-backed walkthrough.
Replay-Driven Testing for Claude API: A Production Pattern for Recording and Replaying Responses
A production-grade design for stabilizing Claude API tests by recording and replaying real responses. Covers cassettes for Messages, Streaming, Tool Use, CI integration, and incident replay.
Running Claude Code × Playwright E2E Tests in Production — Pitfalls and Decision Criteria
Implementation patterns for running E2E tests with Claude Code and Playwright in production, plus how to measure whether the investment pays back. Includes the Cloudflare Workers and Pages preview deployment pitfalls, and a decision framework that indie developers can use to judge whether E2E tests are worth the investment.
Building LLM Evaluation Pipelines with Claude API — Claude-as-Judge, Prompt A/B Testing, and Quality Scoring Patterns
Designing and implementing LLM evaluation pipelines on the Claude API — Claude-as-Judge, prompt A/B testing, quality scoring, and regression testing for production applications.
BDD with Claude Code in Production— From Gherkin Scenario Generation to Cross-Team Test Culture
A production-ready guide to Behavior-Driven Development with Claude Code. Learn how to auto-generate Gherkin scenarios, implement step definitions, integrate with Playwright/Cucumber, and build a cross-team test culture — all with working code examples.
Improving Test Coverage Incrementally with Claude Code
Learn how to use Claude Code to identify uncovered functions, generate targeted tests, and incrementally improve test coverage in TypeScript + Vitest projects.
Testing Claude API Applications — Unit, Integration, and E2E Patterns That Hold Up Against Probabilistic Output
Solve the 'AI output changed and broke my tests' problem for good. Learn to combine mocks, semantic assertions, and snapshot testing into a practical test design pattern for Claude API applications.
Test-Driven Refactoring with Claude Code — Safely Modernizing Legacy Code
Learn how to use Claude Code to safely refactor legacy code by adding tests first. Combine TDD principles with AI assistance to eliminate technical debt without breaking existing functionality.