vanatteveldt/starsengine

Stars! Engine

Engine for an open source stars! clone

This is an attempt at an open source stars! clone. I realize that there have been a number of attempts in the past, so hopefully this can succeed by openness and modularity.

Development Status: Extremely early

This repository will only hold the engine code, i.e. the code that transforms a turn plus orders into the next turn. The webserver and client(s) will get their own repository.

Design

1. The "engine" is responsible to turning universe+orders into a new universe.
2. Some other program (e.g. the current starserver stub) is responsible to handling the external interface, validating and merging files, keeping track of state, etc etc.
3. The engine consists of approximately* one module for each item in the order of events
4. Each module takes universe+orders as input and outputs the new universe (optionally plus the orders)

python-pseudocode for the engine (taking http://www.starsfaq.com/order_events.htm as reference)

def process_turn(universe, orders):
   universe = scrapping_fleets(universe, orders)
   universe = manual_load(universe, orders)
   universe = wp0_unload(universe, orders)
   ....
   universe = remote_terraform(universe, orders) 
   return universe

Testing

Unit testing is important for any good program, but especially for 'backend' code test-driven development is a great way to write good code. The basic idea of test driven development is that you write unit tests before writing the actual code, and add specific tests for any corner case you can think of. During development, you don't run the normal code or separate main code to test, but use the unit tests for this.

Setting up the testing environment

We currently use nose tests. On linux systems and presumably on Mac, it is important to tell nosetests to run python3 instead of the python2 that is often still installed by default. The best way to do this is in a virtual environment:

sudo apt-get install python-virtualenv python3
virtualenv -p /usr/bin/python3 env
source env/bin/activate
pip install nose

(the first line is debian/ubuntu specific, but it should be easy to install virtualenv and python3 on other systems as well)

Running tests

which can be used simply by typing nosetests from the console in the repository folder (or in your favourite IDE). You can also specify a specific test to run, e.g. nosetests tests/test_pop_growth.py.

If you use a virtual environment such as described above, be sure to run source env/bin/activate before running any tests.

(master) ~/starsengine$ nosetests
..
----------------------------------------------------------------------
Ran 2 tests in 0.006s

OK
 (master) ~/starsengine$ nosetests tests/test_pop_growth.py
.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

Every push is also automatically unit tested by travis, and a developer that 'breaks' a build will get an automatic email about it.