synapse-old/v1.51/code_style.html

433 lines
27 KiB
HTML
Raw Normal View History

<!DOCTYPE HTML>
<html lang="en" class="sidebar-visible no-js light">
<head>
<!-- Book generated using mdBook -->
<meta charset="UTF-8">
<title>Code Style - Synapse</title>
<!-- Custom HTML head -->
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<meta name="description" content="">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="theme-color" content="#ffffff" />
<link rel="icon" href="favicon.svg">
<link rel="shortcut icon" href="favicon.png">
<link rel="stylesheet" href="css/variables.css">
<link rel="stylesheet" href="css/general.css">
<link rel="stylesheet" href="css/chrome.css">
<link rel="stylesheet" href="css/print.css" media="print">
<!-- Fonts -->
<link rel="stylesheet" href="FontAwesome/css/font-awesome.css">
<link rel="stylesheet" href="fonts/fonts.css">
<!-- Highlight.js Stylesheets -->
<link rel="stylesheet" href="highlight.css">
<link rel="stylesheet" href="tomorrow-night.css">
<link rel="stylesheet" href="ayu-highlight.css">
<!-- Custom theme stylesheets -->
<link rel="stylesheet" href="docs/website_files/table-of-contents.css">
<link rel="stylesheet" href="docs/website_files/remove-nav-buttons.css">
<link rel="stylesheet" href="docs/website_files/indent-section-headers.css">
</head>
<body>
<!-- Provide site root to javascript -->
<script type="text/javascript">
var path_to_root = "";
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
</script>
<!-- Work around some values being stored in localStorage wrapped in quotes -->
<script type="text/javascript">
try {
var theme = localStorage.getItem('mdbook-theme');
var sidebar = localStorage.getItem('mdbook-sidebar');
if (theme.startsWith('"') && theme.endsWith('"')) {
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
}
if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
}
} catch (e) { }
</script>
<!-- Set the theme before any content is loaded, prevents flash -->
<script type="text/javascript">
var theme;
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
if (theme === null || theme === undefined) { theme = default_theme; }
var html = document.querySelector('html');
html.classList.remove('no-js')
html.classList.remove('light')
html.classList.add(theme);
html.classList.add('js');
</script>
<!-- Hide / unhide sidebar before it is displayed -->
<script type="text/javascript">
var html = document.querySelector('html');
var sidebar = 'hidden';
if (document.body.clientWidth >= 1080) {
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
sidebar = sidebar || 'visible';
}
html.classList.remove('sidebar-visible');
html.classList.add("sidebar-" + sidebar);
</script>
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
<div class="sidebar-scrollbox">
<ol class="chapter"><li class="chapter-item expanded affix "><li class="part-title">Introduction</li><li class="chapter-item expanded "><a href="welcome_and_overview.html">Welcome and Overview</a></li><li class="chapter-item expanded affix "><li class="part-title">Setup</li><li class="chapter-item expanded "><a href="setup/installation.html">Installation</a></li><li class="chapter-item expanded "><a href="postgres.html">Using Postgres</a></li><li class="chapter-item expanded "><a href="reverse_proxy.html">Configuring a Reverse Proxy</a></li><li class="chapter-item expanded "><a href="setup/forward_proxy.html">Configuring a Forward/Outbound Proxy</a></li><li class="chapter-item expanded "><a href="turn-howto.html">Configuring a Turn Server</a></li><li class="chapter-item expanded "><a href="delegate.html">Delegation</a></li><li class="chapter-item expanded affix "><li class="part-title">Upgrading</li><li class="chapter-item expanded "><a href="upgrade.html">Upgrading between Synapse Versions</a></li><li class="chapter-item expanded "><a href="MSC1711_certificates_FAQ.html">Upgrading from pre-Synapse 1.0</a></li><li class="chapter-item expanded affix "><li class="part-title">Usage</li><li class="chapter-item expanded "><a href="federate.html">Federation</a></li><li class="chapter-item expanded "><a href="usage/configuration/index.html">Configuration</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="usage/configuration/homeserver_sample_config.html">Homeserver Sample Config File</a></li><li class="chapter-item expanded "><a href="usage/configuration/logging_sample_config.html">Logging Sample Config File</a></li><li class="chapter-item expanded "><a href="structured_logging.html">Structured Logging</a></li><li class="chapter-item expanded "><a href="templates.html">Templates</a></li><li class="chapter-item expanded "><a href="usage/configuration/user_authentication/index.html">User Authentication</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="usage/configuration/user_authentication/single_sign_on/index.html">Single-Sign On</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="openid.html">OpenID Connect</a></li><li class="chapter-item expanded "><a href="usage/configuration/user_authentication/single_sign_on/saml.html">SAML</a></li><li class="chapter-item expanded "><a href="usage/configuration/user_authentication/single_sign_on/cas.html">CAS</a></li><li class="chapter-item expanded "><a href="sso_mapping_providers.html">SSO Mapping Providers</a></li></ol></li><li class="chapter-item expanded "><a href="password_auth_providers.html">Password Auth Providers</a></li><li class="chapter-item expanded "><a href="jwt.html">JSON Web Tokens</a></li><li class="chapter-item expanded "><a href="usage/configuration/user_authentication/refresh_tokens.html">Refresh Tokens</a></li></ol></li><li class="chapter-item expanded "><a href="CAPTCHA_SETUP.html">Registration Captcha</a></li><li class="chapter-item expanded "><a href="application_services.html">Application Services</a></li><li class="chapter-item expanded "><a href="server_notices.html">Server Notices</a></li><li class="chapter-item expanded "><a href="consent_tracking.html">Consent Tracking</a></li><li class="chapter-item expanded "><a href="development/url_previews.html">URL Previews</a></li><li class="chapter-item expanded "><a href="user_directory.html">User Directory</a></li><li class="chapter-item expanded "><a href="message_retention_policies.html">Message Retention Policies</a></li><li class="chapter-item expanded "><a href="modules/index.html">Pluggable Modules</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="modules/writing_a_module.html">Writing a module</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="modules/spam_checker_callbacks.html">Spam checker callbacks</a></li><li class="chapter-item expanded "><a href="modules/third_party_rules_callbacks.html">Third-party rules callbacks</a></li><li class="chapter-item expanded "><a
</div>
<div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
</nav>
<div id="page-wrapper" class="page-wrapper">
<div class="page">
<div id="menu-bar-hover-placeholder"></div>
<div id="menu-bar" class="menu-bar sticky bordered">
<div class="left-buttons">
<button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
<i class="fa fa-bars"></i>
</button>
<button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
<i class="fa fa-paint-brush"></i>
</button>
<ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
<li role="none"><button role="menuitem" class="theme" id="light">Light (default)</button></li>
<li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
<li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
<li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
<li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
</ul>
<button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
<i class="fa fa-search"></i>
</button>
</div>
<h1 class="menu-title">Synapse</h1>
<div class="right-buttons">
<a href="print.html" title="Print this book" aria-label="Print this book">
<i id="print-button" class="fa fa-print"></i>
</a>
<a href="https://github.com/matrix-org/synapse" title="Git repository" aria-label="Git repository">
<i id="git-repository-button" class="fa fa-github"></i>
</a>
<a href="https://github.com/matrix-org/synapse/edit/develop/docs/code_style.md" title="Suggest an edit" aria-label="Suggest an edit">
<i id="git-edit-button" class="fa fa-edit"></i>
</a>
</div>
</div>
<div id="search-wrapper" class="hidden">
<form id="searchbar-outer" class="searchbar-outer">
<input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
</form>
<div id="searchresults-outer" class="searchresults-outer hidden">
<div id="searchresults-header" class="searchresults-header"></div>
<ul id="searchresults">
</ul>
</div>
</div>
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
<script type="text/javascript">
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
});
</script>
<div id="content" class="content">
<main>
<!-- Page table of contents -->
<div class="sidetoc">
<nav class="pagetoc"></nav>
</div>
<h1 id="code-style"><a class="header" href="#code-style">Code Style</a></h1>
<h2 id="formatting-tools"><a class="header" href="#formatting-tools">Formatting tools</a></h2>
<p>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.</p>
<p>The necessary tools are detailed below.</p>
<p>First install them with:</p>
<pre><code class="language-sh">pip install -e &quot;.[lint,mypy]&quot;
</code></pre>
<ul>
<li>
<p><strong>black</strong></p>
<p>The Synapse codebase uses <a href="https://pypi.org/project/black/">black</a>
as an opinionated code formatter, ensuring all comitted code is
properly formatted.</p>
<p>Have <code>black</code> auto-format your code (it shouldn't change any
functionality) with:</p>
<pre><code class="language-sh">black . --exclude=&quot;\.tox|build|env&quot;
</code></pre>
</li>
<li>
<p><strong>flake8</strong></p>
<p><code>flake8</code> is a code checking tool. We require code to pass <code>flake8</code>
before being merged into the codebase.</p>
<p>Check all application and test code with:</p>
<pre><code class="language-sh">flake8 synapse tests
</code></pre>
</li>
<li>
<p><strong>isort</strong></p>
<p><code>isort</code> ensures imports are nicely formatted, and can suggest and
auto-fix issues such as double-importing.</p>
<p>Auto-fix imports with:</p>
<pre><code class="language-sh">isort -rc synapse tests
</code></pre>
<p><code>-rc</code> means to recursively search the given directories.</p>
</li>
</ul>
<p>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 <code>flake8</code> on
save as it takes a while and is very resource intensive.</p>
<h2 id="general-rules"><a class="header" href="#general-rules">General rules</a></h2>
<ul>
<li><strong>Naming</strong>:
<ul>
<li>Use camel case for class and type names</li>
<li>Use underscores for functions and variables.</li>
</ul>
</li>
<li><strong>Docstrings</strong>: should follow the <a href="https://google.github.io/styleguide/pyguide.html#38-comments-and-docstrings">google code
style</a>.
See the
<a href="http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html">examples</a>
in the sphinx documentation.</li>
<li><strong>Imports</strong>:
<ul>
<li>
<p>Imports should be sorted by <code>isort</code> as described above.</p>
</li>
<li>
<p>Prefer to import classes and functions rather than packages or
modules.</p>
<p>Example:</p>
<pre><code class="language-python">from synapse.types import UserID
...
user_id = UserID(local, server)
</code></pre>
<p>is preferred over:</p>
<pre><code class="language-python">from synapse import types
...
user_id = types.UserID(local, server)
</code></pre>
<p>(or any other variant).</p>
<p>This goes against the advice in the Google style guide, but it
means that errors in the name are caught early (at import time).</p>
</li>
<li>
<p>Avoid wildcard imports (<code>from synapse.types import *</code>) and
relative imports (<code>from .types import UserID</code>).</p>
</li>
</ul>
</li>
</ul>
<h2 id="configuration-file-format"><a class="header" href="#configuration-file-format">Configuration file format</a></h2>
<p>The <a href="./sample_config.yaml">sample configuration file</a> 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.</p>
<p>Some guidelines follow:</p>
<ul>
<li>
<p>Sections should be separated with a heading consisting of a single
line prefixed and suffixed with <code>##</code>. There should be <strong>two</strong> blank
lines before the section header, and <strong>one</strong> after.</p>
</li>
<li>
<p>Each option should be listed in the file with the following format:</p>
<ul>
<li>
<p>A comment describing the setting. Each line of this comment
should be prefixed with a hash (<code>#</code>) and a space.</p>
<p>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.</p>
<p>Often, the comment end with something like &quot;uncomment the
following to <do action>&quot;.</p>
</li>
<li>
<p>A line consisting of only <code>#</code>.</p>
</li>
<li>
<p>A commented-out example setting, prefixed with only <code>#</code>.</p>
<p>For boolean (on/off) options, convention is that this example
should be the <em>opposite</em> to the default (so the comment will end
with &quot;Uncomment the following to enable [or disable]
<feature>.&quot; For other options, the example should give some
non-default value which is likely to be useful to the reader.</p>
</li>
</ul>
</li>
<li>
<p>There should be a blank line between each option.</p>
</li>
<li>
<p>Where several settings are grouped into a single dict, <em>avoid</em> the
convention where the whole block is commented out, resulting in
comment lines starting <code># #</code>, 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 <code>None</code> (as it
will be if no sub-options are enabled).</p>
</li>
<li>
<p>Lines should be wrapped at 80 characters.</p>
</li>
<li>
<p>Use two-space indents.</p>
</li>
<li>
<p><code>true</code> and <code>false</code> are spelt thus (as opposed to <code>True</code>, etc.)</p>
</li>
<li>
<p>Use single quotes (<code>'</code>) rather than double-quotes (<code>&quot;</code>) or backticks
(<code>`</code>) to refer to configuration options.</p>
</li>
</ul>
<p>Example:</p>
<pre><code class="language-yaml">## 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
</code></pre>
<p>Note that the sample configuration is generated from the synapse code
and is maintained by a script, <code>scripts-dev/generate_sample_config</code>.
Making sure that the output from this script matches the desired format
is left as an exercise for the reader!</p>
</main>
<nav class="nav-wrapper" aria-label="Page navigation">
<!-- Mobile navigation buttons -->
<a rel="prev" href="development/contributing_guide.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a rel="next" href="development/git.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
<div style="clear: both"></div>
</nav>
</div>
</div>
<nav class="nav-wide-wrapper" aria-label="Page navigation">
<a rel="prev" href="development/contributing_guide.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
<i class="fa fa-angle-left"></i>
</a>
<a rel="next" href="development/git.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
<i class="fa fa-angle-right"></i>
</a>
</nav>
</div>
<script type="text/javascript">
window.playground_copyable = true;
</script>
<script src="elasticlunr.min.js" type="text/javascript" charset="utf-8"></script>
<script src="mark.min.js" type="text/javascript" charset="utf-8"></script>
<script src="searcher.js" type="text/javascript" charset="utf-8"></script>
<script src="clipboard.min.js" type="text/javascript" charset="utf-8"></script>
<script src="highlight.js" type="text/javascript" charset="utf-8"></script>
<script src="book.js" type="text/javascript" charset="utf-8"></script>
<!-- Custom JS scripts -->
<script type="text/javascript" src="docs/website_files/table-of-contents.js"></script>
</body>
</html>