Claude Code in Your Development Flow By the end of this lesson, students should be able to: Behavior-focused test generation. The default Claude Code test generation output tests implementation details – what internal functions are called, what exact return structure is produced. These tests break on refactoring even when behavior is preserved. Behavior-focused tests survive refactoring because they test inputs and expected outputs. Request pattern for behavior-focused tests: “ “` The explicit case list in the request is the key element – it forces test coverage of the edge cases you specify rather than the happy path Claude defaults to. The edge-case specification technique. Before asking for test generation, ask Claude to identify edge cases: This two-step pattern produces more comprehensive tests than one-step generation because it forces explicit edge case identification before writing the tests. Scoped code review. The most useful Claude Code review requests are specific: Each scoped review produces findings in a specific domain. Generic "review this code" produces a surface-level observation that requires more follow-up. The pre-commit review habit. A two-minute pre-commit Claude Code review habit: Not every pre-commit review finds something. But the ones that do – catching a missing error handler, an unvalidated input, an off-by-one – are worth the two minutes every time. A developer writes a payment processing function and asks Claude Code to generate tests. First request (generic): Claude generates ten tests that all pass – but seven test internal method calls rather than actual payment outcomes. Second request (behavior-focused with explicit cases): she specifies fourteen behavioral cases including all error paths. Claude generates fourteen tests covering each case. Two of the generated tests fail – surfacing actual bugs in the payment function before they reach staging. The behavior specification, not the generation, was the quality-determining step. When using Claude Code for security-focused code reviews, treat Claude's findings as a first pass, not a comprehensive security audit. AI-assisted review catches common vulnerability patterns well. It does not replace penetration testing, formal security review, or domain-specific security expertise for high-risk applications. Use Claude's security review findings to catch low-hanging-fruit issues before engaging a security specialist. Log in and enroll to access lesson quizzes.
Lesson 4: Test Generation and Code Review with Claude Code
Lesson Objectives
Lesson Content
Write tests for processOrder()` that:src/auth/ for authentication vulnerabilities – specifically session management, token validation, and input sanitization"git diff --staged to see what you are about to commitPractical Example
Safety Notes