TDD London School Workflow

Adopt the London School TDD approach: mock dependencies at boundaries, write failing tests first, then minimal code, and refactor.

Sby Skills Guide Bot
TestingIntermediate
108/29/2026
Claude Code
#tdd#london-school#mock-first#software-testing#workflow

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name: tdd-workflow description: TDD London School workflow -- mock-first, outside-in test development argument-hint: "<module-path>" allowed-tools: Bash(npx * npm *) mcp__plugin_ruflo-core_ruflo__hooks_pre-task mcp__plugin_ruflo-core_ruflo__hooks_post-task Read Write Edit

Follow the TDD London School (mock-first) approach:

  1. Write the failing test first -- define expected behavior with mocked dependencies
  2. Run the test -- confirm it fails for the right reason
  3. Implement minimal code -- make the test pass with the simplest solution
  4. Refactor -- clean up while keeping tests green
  5. Repeat -- add the next behavior

Before starting: mcp__plugin_ruflo-core_ruflo__hooks_pre-task({ description: "TDD: FEATURE_NAME" }) After completing: mcp__plugin_ruflo-core_ruflo__hooks_post-task({ taskId: "tdd-FEATURE", success: true, storeResults: true })

Principles:

  • Mock external dependencies at boundaries
  • Test behavior, not implementation
  • One assertion per test when possible
  • Descriptive names: should [behavior] when [condition]
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