| name | conducty-tdd |
| description | Test-driven development at orchestrator (verification-first planning) and implementer (red-green-refactor) levels. Use when implementing any feature/bugfix, when writing tests, when the plan specifies TDD, or when the user says "TDD", "red-green-refactor", "write the test first". |
| aliases | ["conducty-tdd","tdd"] |
| tags | ["conducty/skill","conducty/tdd"] |
Conducty TDD — Test-Driven Development for Orchestrated Agents
TDD in Conducty operates at two levels: the orchestrator writes the "test" (verification command + acceptance criteria) before writing the prompt, and the implementer follows red-green-refactor within each prompt. Both levels follow the same discipline: define what success looks like before doing the work.
The Two Levels
Level 1: Orchestrator TDD (Plan Time)
The orchestrator (you, during [[conducty-plan]]) writes the verification step FIRST for every prompt. This is the test. If you can't write a concrete verification command, the acceptance criteria aren't clear enough — fix them before generating the prompt.
Define verification → Write prompt → Execute → Verify → Learn
This maps directly to red-green-refactor:
- Red: The verification command would fail right now (feature doesn't exist yet)
- Green: After execution, the verification command passes
- Refactor: In [[conducty-improve]], refine the prompt template based on what worked
If you can't write the verification step, you don't understand what you're building. Go back to [[conducty-shape]].
Level 2: Implementer TDD (Execution Time)
The implementer subagent follows classical red-green-refactor within each prompt:
- RED — Write one minimal test that describes the desired behavior. Run it (Bash). Watch it fail.
- Verify RED — Confirm it fails because the feature is missing, not because of a typo or import error.
- GREEN — Write the simplest code that makes the test pass. Nothing more.
- Verify GREEN — Run the test. Confirm it passes. Run all tests. Confirm no regressions.
- REFACTOR — Clean up: remove duplication, improve names, extract helpers. Keep tests green.
- Repeat — Next behavior, next test.
How They Connect
The orchestrator's verification step is the acceptance test. The implementer's TDD cycle produces unit tests. When the implementer finishes, the orchestrator runs the verification command (via [[conducty-verify]]) to confirm the acceptance test passes. Both levels must be green.
The Iron Law
NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST
This applies to implementers. If code was written before its test, delete the code and start over. Not "adapt it," not "keep it as reference" — delete it and write the test first.
At the orchestrator level: no prompt without a verification step. If the verification field is empty, the prompt is not ready.
Good Tests
Test behavior, not implementation. A test that breaks when you refactor (without changing behavior) is testing the wrong thing. Tests should survive restructuring.
One test, one behavior. If the test name contains "and," split it. Each test should have exactly one reason to fail.
Real code over mocks. Use mocks only when external dependencies force it (network, database, third-party APIs). Mocking your own code means the code is too coupled — fix the coupling.
Names describe the behavior. rejects empty email tells you what broke. test_email_3 tells you nothing.
Failure messages diagnose the problem. A good assertion message tells you what happened and what was expected without reading the test code.
Prompt Smells
Signs that a prompt will fail before you run it. Check for these during [[conducty-plan]] Step 5e.
| Smell | What It Looks Like | Why It Fails | Fix |
|---|
| Vague acceptance | "Make it work" / "Improve performance" | Agent has no concrete target, builds whatever seems right | Add specific criteria: "response time < 200ms for 1000 records" |
| Missing context | Prompt references modules not listed in Context field | Agent can't find the code it needs, guesses at structure | Add the file paths to Context |
| Mixed concerns | One prompt creates a new API endpoint AND redesigns the auth system | Agent loses focus, does both poorly | Split into two prompts |
| No verification | Verification field is empty or says "check manually" | No objective pass/fail — the agent declares victory, you hope | Write a concrete command: npm test -- --grep auth |
| Unbounded scope | "And anything else that needs updating" / no no-go zones | Agent restructures half the codebase "while it's there" | Add explicit no-go zones |
| Exceeds appetite | Time budget says 30 min but it's a 3-file integration task | Agent runs out of budget or produces rushed work | Simplify scope or increase budget |
| Missing characterization | Modifies existing code without verifying current tests pass first | Agent breaks existing behavior without noticing | Add characterization step |
| Implicit knowledge | Assumes agent knows project conventions not stated anywhere | Agent uses its own conventions, inconsistent with codebase | State conventions explicitly or reference context file |
| Dependency on luck | Correct implementation requires choosing the right library/approach | Agent picks wrong approach, wastes the entire prompt | Specify the approach in the prompt |
When to Skip TDD
TDD applies to almost all implementation work. Genuine exceptions:
- Throwaway prototypes the user explicitly marks as disposable
- Generated code from tools (schema generators, scaffolding) where tests are pre-provided
- Configuration changes that don't have testable behavior (though verification still applies)
"This is too simple for TDD" is not an exception. Simple code breaks. The test takes 30 seconds. Write it.
Integration with Conducty
- [[conducty-plan]] references this skill when writing prompt templates — every feature and bugfix template includes TDD steps
- [[conducty-execute]] ensures implementer subagents follow TDD within their prompts
- [[conducty-verify]] is the orchestrator-level "test run" — it validates the acceptance criteria
- [[conducty-improve]] learns from test failures to improve future prompt templates
- Prompt smells are checked during [[conducty-plan]] Step 5e before the plan is finalized
