CounterDroneBackend/AGENTS.md

CLAUDE.md

1. Think Before Coding

Don't assume. Don't hide confusion. Surface tradeoffs.

Before implementing:

• State your assumptions explicitly. If uncertain, ask.
• If multiple interpretations exist, present them - don't pick silently.
• If a simpler approach exists, say so. Push back when warranted.
• If something is unclear, stop. Name what's confusing. Ask.

2. Simplicity First

Minimum code that solves the problem. Nothing speculative.

• No features beyond what was asked.
• No abstractions for single-use code.
• No "flexibility" or "configurability" that wasn't requested.
• No error handling for impossible scenarios.
• If you write 200 lines and it could be 50, rewrite it.

Ask yourself: "Would a senior engineer say this is overcomplicated?" If yes, simplify.

3. Surgical Changes

Touch only what you must. Clean up only your own mess.

When editing existing code:

• Don't "improve" adjacent code, comments, or formatting.
• Don't refactor things that aren't broken.
• Match existing style, even if you'd do it differently.
• If you notice unrelated dead code, mention it - don't delete it.

When your changes create orphans:

• Remove imports/variables/functions that YOUR changes made unused.
• Don't remove pre-existing dead code unless asked.

The test: Every changed line should trace directly to the user's request.

4. Goal-Driven Execution

Define success criteria. Loop until verified.

Transform tasks into verifiable goals:

• "Add validation" → "Write tests for invalid inputs, then make them pass"
• "Fix the bug" → "Write a test that reproduces it, then make it pass"
• "Refactor X" → "Ensure tests pass before and after"

For multi-step tasks, state a brief plan:

1. [Step] → verify: [check]
2. [Step] → verify: [check]
3. [Step] → verify: [check]

Strong success criteria let you loop independently. Weak criteria ("make it work") require constant clarification.

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5. Use PowerShell for Shell Commands

All shell commands, scripts, rg/fd calls run through pwsh, never cmd or bash.

• Prefix every shell invocation with pwsh -Command "..."
• Example: pwsh -Command "rg -n 'class' src/"
• Example: pwsh -Command "./build.bat"

6. Verify Unity Scripts After Changes

After modifying src/CounterDrone.Core/ or src/Unity/Assets/Scripts/, run:

pwsh scripts/check_unity_build.ps1

This automatically rebuilds Core.dll, copies it to Unity Plugins, and compiles Unity scripts. Exits 0 if all pass.

7. Run Targeted Tests First

Always run the narrowest relevant test first. If you just changed DefensePlannerTests, run --filter 'FullyQualifiedName~DefensePlannerTests'. If you changed FullPipelineTests, run that filter. Don't start with dotnet test on the whole project — it wastes time and buries the failures you're looking for.

Run full suite only after the targeted tests pass, to verify nothing else broke.

# Run a test class:
pwsh -Command "dotnet test test/unit/CounterDrone.Core.Tests/ --filter 'FullyQualifiedName~DefensePlannerTests'"

# Run a single test:
pwsh -Command "dotnet test test/unit/CounterDrone.Core.Tests/ --filter 'FullyQualifiedName~Scenario_AirBased'"

# Run full suite (only after targeted passes):
pwsh -Command "dotnet test test/unit/CounterDrone.Core.Tests/"

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These guidelines are working if: fewer unnecessary changes in diffs, fewer rewrites due to overcomplication, and clarifying questions come before implementation rather than after mistakes.