---
description: "Enforces concise, comment-free, environment-aware coding standards with strict scope discipline and test verification"
alwaysApply: true
---
# Coding preferences
- Always prefer simple solution
- Generate concise code
- Do not put comments in the code, except in tests: every test must use the Arrange / Act / Assert pattern with language-appropriate comment syntax (`# Arrange` for Python, `// Arrange` for C#/Rust/JS/TS). Omit any section that is not needed (e.g. if there is no setup, skip Arrange; if act and assert are the same line, keep only Assert)
- Do not put logs unless it is an exception, or was asked specifically
- Do not put code annotations unless it was asked specifically 
- Write code that takes into account the different environments: development, production
- You are careful to make changes that are requested or you are confident the changes are well understood and related to the change being requested
- Mocking data is needed only for tests, never mock data for dev or prod env
- Make test environment (files, db and so on) as close as possible to the production environment
- When you add new libraries or dependencies make sure you are using the same version of it as other parts of the code
- When writing code that calls a library API, verify the API actually exists in the pinned version. Check the library's changelog or migration guide for breaking changes between major versions. Never assume an API works at a given version — test the actual call path before committing.
- When a test fails due to a missing dependency, install it — do not fake or stub the module system. For normal packages, add them to the project's dependency file (requirements-test.txt, package.json devDependencies, test csproj, etc.) and install. Only consider stubbing if the dependency is heavy (e.g. hardware-specific SDK, large native toolchain) — and even then, ask the user first before choosing to stub.
- Do not solve environment or infrastructure problems (dependency resolution, import paths, service discovery, connection config) by hardcoding workarounds in source code. Fix them at the environment/configuration level.
- Before writing new infrastructure or workaround code, check how the existing codebase already handles the same concern. Follow established project patterns.
- If a file, class, or function has no remaining usages — delete it. Do not keep dead code "just in case"; git history preserves everything. Dead code rots: its dependencies drift, it misleads readers, and it breaks when the code it depends on evolves.

- Focus on the areas of code relevant to the task
- Do not touch code that is unrelated to the task
- Always think about what other methods and areas of code might be affected by the code changes
- When you think you are done with changes, run the full test suite. Every failure — including pre-existing ones, collection errors, and import errors — is a **blocking gate**. Never silently ignore, skip, or proceed past a failing test. On any failure, stop and ask the user to choose one of:
  - **Investigate and fix** the failing test or source code
  - **Remove the test** if it is obsolete or no longer relevant
- Do not rename any databases or tables or table columns without confirmation. Avoid such renaming if possible.

- Make sure we don't commit binaries, create and keep .gitignore up to date and delete binaries after you are done with the task
- Never force-push to main or dev branches
- Place all source code under the `src/` directory; keep project-level config, tests, and tooling at the repo root
