mirror of
https://github.com/element-hq/synapse
synced 2024-08-21 10:10:20 +00:00
170 lines
5.7 KiB
Markdown
170 lines
5.7 KiB
Markdown
# Code Style
|
|
|
|
## Formatting tools
|
|
|
|
The Synapse codebase uses a number of code formatting tools in order to
|
|
quickly and automatically check for formatting (and sometimes logical)
|
|
errors in code.
|
|
|
|
The necessary tools are detailed below.
|
|
|
|
- **black**
|
|
|
|
The Synapse codebase uses [black](https://pypi.org/project/black/)
|
|
as an opinionated code formatter, ensuring all comitted code is
|
|
properly formatted.
|
|
|
|
First install `black` with:
|
|
|
|
pip install --upgrade black
|
|
|
|
Have `black` auto-format your code (it shouldn't change any
|
|
functionality) with:
|
|
|
|
black . --exclude="\.tox|build|env"
|
|
|
|
- **flake8**
|
|
|
|
`flake8` is a code checking tool. We require code to pass `flake8`
|
|
before being merged into the codebase.
|
|
|
|
Install `flake8` with:
|
|
|
|
pip install --upgrade flake8 flake8-comprehensions
|
|
|
|
Check all application and test code with:
|
|
|
|
flake8 synapse tests
|
|
|
|
- **isort**
|
|
|
|
`isort` ensures imports are nicely formatted, and can suggest and
|
|
auto-fix issues such as double-importing.
|
|
|
|
Install `isort` with:
|
|
|
|
pip install --upgrade isort
|
|
|
|
Auto-fix imports with:
|
|
|
|
isort -rc synapse tests
|
|
|
|
`-rc` means to recursively search the given directories.
|
|
|
|
It's worth noting that modern IDEs and text editors can run these tools
|
|
automatically on save. It may be worth looking into whether this
|
|
functionality is supported in your editor for a more convenient
|
|
development workflow. It is not, however, recommended to run `flake8` on
|
|
save as it takes a while and is very resource intensive.
|
|
|
|
## General rules
|
|
|
|
- **Naming**:
|
|
- Use camel case for class and type names
|
|
- Use underscores for functions and variables.
|
|
- **Docstrings**: should follow the [google code
|
|
style](https://google.github.io/styleguide/pyguide.html#38-comments-and-docstrings).
|
|
This is so that we can generate documentation with
|
|
[sphinx](http://sphinxcontrib-napoleon.readthedocs.org/en/latest/).
|
|
See the
|
|
[examples](http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html)
|
|
in the sphinx documentation.
|
|
- **Imports**:
|
|
- Imports should be sorted by `isort` as described above.
|
|
- Prefer to import classes and functions rather than packages or
|
|
modules.
|
|
|
|
Example:
|
|
|
|
from synapse.types import UserID
|
|
...
|
|
user_id = UserID(local, server)
|
|
|
|
is preferred over:
|
|
|
|
from synapse import types
|
|
...
|
|
user_id = types.UserID(local, server)
|
|
|
|
(or any other variant).
|
|
|
|
This goes against the advice in the Google style guide, but it
|
|
means that errors in the name are caught early (at import time).
|
|
|
|
- Avoid wildcard imports (`from synapse.types import *`) and
|
|
relative imports (`from .types import UserID`).
|
|
|
|
## Configuration file format
|
|
|
|
The [sample configuration file](./sample_config.yaml) acts as a
|
|
reference to Synapse's configuration options for server administrators.
|
|
Remember that many readers will be unfamiliar with YAML and server
|
|
administration in general, so that it is important that the file be as
|
|
easy to understand as possible, which includes following a consistent
|
|
format.
|
|
|
|
Some guidelines follow:
|
|
|
|
- Sections should be separated with a heading consisting of a single
|
|
line prefixed and suffixed with `##`. There should be **two** blank
|
|
lines before the section header, and **one** after.
|
|
- Each option should be listed in the file with the following format:
|
|
- A comment describing the setting. Each line of this comment
|
|
should be prefixed with a hash (`#`) and a space.
|
|
|
|
The comment should describe the default behaviour (ie, what
|
|
happens if the setting is omitted), as well as what the effect
|
|
will be if the setting is changed.
|
|
|
|
Often, the comment end with something like "uncomment the
|
|
following to <do action>".
|
|
|
|
- A line consisting of only `#`.
|
|
- A commented-out example setting, prefixed with only `#`.
|
|
|
|
For boolean (on/off) options, convention is that this example
|
|
should be the *opposite* to the default (so the comment will end
|
|
with "Uncomment the following to enable [or disable]
|
|
<feature>." For other options, the example should give some
|
|
non-default value which is likely to be useful to the reader.
|
|
|
|
- There should be a blank line between each option.
|
|
- Where several settings are grouped into a single dict, *avoid* the
|
|
convention where the whole block is commented out, resulting in
|
|
comment lines starting `# #`, as this is hard to read and confusing
|
|
to edit. Instead, leave the top-level config option uncommented, and
|
|
follow the conventions above for sub-options. Ensure that your code
|
|
correctly handles the top-level option being set to `None` (as it
|
|
will be if no sub-options are enabled).
|
|
- Lines should be wrapped at 80 characters.
|
|
- Use two-space indents.
|
|
|
|
Example:
|
|
|
|
## Frobnication ##
|
|
|
|
# The frobnicator will ensure that all requests are fully frobnicated.
|
|
# To enable it, uncomment the following.
|
|
#
|
|
#frobnicator_enabled: true
|
|
|
|
# By default, the frobnicator will frobnicate with the default frobber.
|
|
# The following will make it use an alternative frobber.
|
|
#
|
|
#frobincator_frobber: special_frobber
|
|
|
|
# Settings for the frobber
|
|
#
|
|
frobber:
|
|
# frobbing speed. Defaults to 1.
|
|
#
|
|
#speed: 10
|
|
|
|
# frobbing distance. Defaults to 1000.
|
|
#
|
|
#distance: 100
|
|
|
|
Note that the sample configuration is generated from the synapse code
|
|
and is maintained by a script, `scripts-dev/generate_sample_config`.
|
|
Making sure that the output from this script matches the desired format
|
|
is left as an exercise for the reader!
|