dcsplan: a tactical planner

dcsplan is a web app helping plan missions for combat flight simulators such as DCS. Its main advantage is to generate detailed kneeboards allowing mission following and navigation, even in aircrafts with limited onboard systems (such as 60s era jets).

An online server is accessible at https://dcsplan.bonnefon.org/

Main features

• Online edition of flight plans
• Maps from DCS itself for accuracy of landmarks in the sim
• Generate kneeboards, one page per leg
• Draw accurate turns based on ground speed and bank angle

Project Structure

This is a monorepo using pnpm workspaces.

• packages/frontend: Vite/React/TypeScript front-end application.
• packages/backend: FastAPI/Python back-end application.

Getting Started

Prerequisites

• Node.js 24 and pnpm (the version is pinned by packageManager in package.json; corepack enable picks it up)
• uv (brew install uv). It installs the Python version the backend needs (3.13, from packages/backend/.python-version) if you don't have it.

Installation

1. Install front-end dependencies: From the root of the project, run:

   pnpm install

   This will install dependencies for the root workspace and the front-end package (once it's created).

2. Set up and install back-end dependencies: This runs uv sync, which creates packages/backend/.venv and installs the locked dependencies from packages/backend/uv.lock (runtime and dev).

   pnpm run install:backend

   If you have an old packages/backend/venv from before the move to uv, delete it.

   Dependencies are declared in packages/backend/pyproject.toml. To add or upgrade one, use uv from packages/backend (uv add <pkg>, uv add --dev <pkg>, uv lock --upgrade-package <pkg>) and commit uv.lock. To run any other backend command in the environment, prefix it with uv run (for example uv run python -m some_module).

Running the Development Servers

To run both the front-end and back-end servers concurrently, use the following command from the root directory:

pnpm dev

• The front-end (Vite) will be available at http://localhost:5173 (or the next available port).
• The back-end (FastAPI) will be available at http://localhost:8000.

Running the Tests

To run all tests (back-end and front-end):

pnpm test

To run back-end tests only:

pnpm test:backend

To run front-end tests only:

pnpm test:frontend

Golden Files

Some tests compare computed values with golden files stored in packages/shared/. Each file is written by one test file when it is run with UPDATE_GOLDEN=1 (any value works):

Golden file	Written by	Regenerate when
map-georeference/projected-control-points.json	packages/backend/test_map_georeference.py	A map is added, or its crs or control points change
theatre-golden/backend-expected.json	packages/backend/test_theatre_golden.py	A change in the back-end's computed leg values is intended
theatre-golden/frontend-expected.json	packages/frontend/src/utils/theatreGolden.test.ts	A change in the front-end's computed leg values is intended

cd packages/backend
UPDATE_GOLDEN=1 .venv/bin/python -m pytest test_map_georeference.py
UPDATE_GOLDEN=1 .venv/bin/python -m pytest test_theatre_golden.py

cd packages/frontend
UPDATE_GOLDEN=1 pnpm vitest run src/utils/theatreGolden.test.ts

• The file is written as soon as the test file is loaded, so always name the test file: running a whole suite with UPDATE_GOLDEN=1 rewrites every golden file it contains.
• The theatre golden files exist to catch unintended changes in headings, distances, times and fuel. Regenerate them only when such a change is intended.
• The control point fixture holds each control point projected with pyproj (back-end). The front-end test src/utils/mapGeoreferenceParity.test.ts reads it and checks that proj4js projects the same points within 0.01 m. Regenerate it from the back-end first, then run that front-end test.
• Run the tests again without UPDATE_GOLDEN and review the JSON diff before committing.