Use Case: Implementation
Scenario 1: Python API Endpoint
Section titled “Scenario 1: Python API Endpoint”Profile: Junior Developer, implementing a REST endpoint for the first time with TDD
Step 1: Start with tests
Section titled “Step 1: Start with tests”“I need to add a POST /users endpoint. Let me write tests first.”
Tool: /tdd (command) invokes tdd-guide agent (Sonnet)
| Input | Endpoint spec: POST /users with email, name fields; returns 201 with user object |
| Output | Failing test file (tests/test_users.py) covering happy path, validation errors, duplicates |
Step 2: Make tests pass
Section titled “Step 2: Make tests pass”“Tests are red. Now implement the endpoint.”
Tool: tdd-guide agent continues (GREEN phase)
| Input | Failing tests + endpoint requirements |
| Output | Implementation code that makes all tests pass with minimal logic |
Step 3: Apply Python patterns
Section titled “Step 3: Apply Python patterns”Active automatically while writing Python code
Tool: python-patterns skill (always-on knowledge)
| Input | Python code being written |
| Output | Guidance: type hints, EAFP error handling, context managers, PEP 8 |
Step 4: Refactor
Section titled “Step 4: Refactor”“Tests pass. Clean up the code.”
Tool: tdd-guide agent continues (REFACTOR phase)
| Input | Green test suite + implementation |
| Output | Cleaner code with the same passing tests. No new functionality. |
Scenario 2: TypeScript React Component
Section titled “Scenario 2: TypeScript React Component”Profile: Senior Developer, adding a data table with sorting and filtering
Step 1: Plan the implementation
Section titled “Step 1: Plan the implementation”“I need a sortable, filterable data table component.”
Tool: /plan (command)
| Input | Component requirements: column sorting, text filter, pagination |
| Output | Implementation plan: props interface, sort state, filter logic, test plan |
Step 2: TDD the component
Section titled “Step 2: TDD the component”“Let me write tests first for the sorting logic.”
Tool: /tdd (command)
| Input | Sort function requirements: ascending/descending, multi-column, null handling |
| Output | Test file + implementation following TypeScript coding standards |
Step 3: TypeScript patterns apply
Section titled “Step 3: TypeScript patterns apply”Active automatically in TypeScript context
Tool: coding-standards skill (always-on knowledge)
| Input | TypeScript/React code being written |
| Output | Guidance: strict types (no any), immutable state, proper dependency arrays, error boundaries |
Python vs TypeScript: Which Tools?
Section titled “Python vs TypeScript: Which Tools?”| Need | Python | TypeScript |
|---|---|---|
| Language patterns | python-patterns skill | coding-standards skill |
| Testing patterns | python-testing skill | coding-standards (testing section) |
| Code review | python-reviewer agent | typescript-reviewer agent |
| TDD workflow | Same: /tdd command | Same: /tdd command |
| Build fixing | Same: /build-fix command | Same: /build-fix command |
Key insight: Commands (/tdd, /build-fix) are language-agnostic. Skills and agents are language-specific. Use the right skill for patterns, the right agent for review.