Contribution guidelines

Quality has highest priority

Write readable code

Developers spend about 25% writing code, but 75% reading it. Writing readable code saves a lot of time.

• Keep the coding style consistent
• Prefer longer, unambiguous names over short but ambiguous ones
• Prefer slower but easily readable code over short/fast but hard to read code (if it doesn't noticeable affect performance)
• Even small things matter; If a space character is superfluous, remove it, if it is missing, add it.

Chose quality over quantity

While quick and dirty implementations may save time in the short run, they will cost more in the long run.

• "Quick and dirty" is almost never an option, there is only "clean and solid"
• Always mark temporary or unfinished solutions using either TODO or FIXME with an explaining comment
  • Use FIXME for code that is wrong or missing
  • Use TODO for code that works, but needs to be improved

Adding features

1. Make sure there is an issue on github and assign it to yourself
2. Create a new branch the feature, based on latest master. Name it feature/#00-some-keywords where 00 is the issue ID. Example: feature/#23-auto-update
3. Always include the issue ID in a commit comment, e. g. #23 implemented update task

Definition of done (DOD)

To be considered as "done", a feature must:

• Have >80% test coverage (line & branch)
• Be reviewed by another contributor
• Be ready to be merged into master

Logging

• Always use SLF4J logger (copy from existing classes)
• Never use System.out
• Put interesting information in front, additional information at the end
• Put values either in single quotes or after colons. Example: User '{}' sent message: {}

Log level	When to use	When not to use	Example
TRACE	Information that is low level and only of interest during development.	Any other purpose	Network traffic, Received 512 bytes from FA, Creating directory xxx
DEBUG	Information that is important to understand problems. Use for repeating things.	Any other purpose	Received game info from server: GameInfo{uid=3876249, title='All welcome!!!', state=OPEN}
INFO	Events that are interesting ("milestones").	For repeating things	Connected to server at lobby.faforever.com:8167
WARN	Events that need attention but don't lead to malfunction	Any other purpose	Could not connect to lobby.faforever.com:8167
ERROR	If, and only if, something is unexpected, unrecoverable or leads to data loss or malfunction	Things that are recoverable	Cannot read client.prefs