Add exception hierarchy to the documentation.

docs/_static/style.css

@@ -322,6 +322,21 @@ div.helpful > p.admonition-title:after {
   content: unset;
 }
 
+/* exception hierarchy */
+
+.exception-hierarchy-content dd,
+.exception-hierarchy-content dl {
+  margin: 0px 2px;
+}
+
+.exception-hierarchy-content {
+  margin-left: 0.5em;
+}
+
+.exception-hierarchy-content ul {
+  list-style: '»' !important;
+}
+
 pre {
   background-color: #f5f5f5;
   border: 1px solid #C6C9CB;

docs/api.rst

@@ -2196,3 +2196,20 @@ The following exceptions are thrown by the library.
 .. autoexception:: discord.opus.OpusError
 
 .. autoexception:: discord.opus.OpusNotLoaded
+
+Exception Hierarchy
+~~~~~~~~~~~~~~~~~~~~~
+
+.. exception_hierarchy::
+
+    - :exc:`Exception`
+        - :exc:`DiscordException`
+            - :exc:`ClientException`
+            - :exc:`NoMoreItems`
+            - :exc:`GatewayNotFound`
+            - :exc:`HTTPException`
+                - :exc:`Forbidden`
+                - :exc:`NotFound`
+            - :exc:`InvalidArgument`
+            - :exc:`LoginFailure`
+            - :exc:`ConnectionClosed`

docs/conf.py

@@ -36,7 +36,8 @@ extensions = [
     'sphinx.ext.intersphinx',
     'sphinx.ext.napoleon',
     'sphinxcontrib.asyncio',
-    'details'
+    'details',
+    'exception_hierarchy'
 ]
 
 autodoc_member_order = 'bysource'

docs/ext/commands/api.rst

@@ -214,8 +214,8 @@ Converters
 
 .. _ext_commands_api_errors:
 
-Errors
+Exceptions
--------
+-----------
 
 .. autoexception:: discord.ext.commands.CommandError
     :members:
@@ -265,3 +265,25 @@ Errors
 .. autoexception:: discord.ext.commands.BotMissingPermissions
     :members:
 
+Exception Hierarchy
++++++++++++++++++++++
+
+.. exception_hierarchy::
+
+    - :exc:`~.DiscordException`
+        - :exc:`~.commands.CommandError`
+            - :exc:`~.commands.ConversionError`
+            - :exc:`~.commands.UserInputError`
+                - :exc:`~.commands.MissingRequiredArgument`
+                - :exc:`~.commands.TooManyArguments`
+                - :exc:`~.commands.BadArgument`
+                - :exc:`~.commands.BadUnionArgument`
+            - :exc:`~.commands.CommandNotFound`
+            - :exc:`~.commands.CheckFailure`
+                - :exc:`~.commands.NoPrivateMessage`
+                - :exc:`~.commands.NotOwner`
+                - :exc:`~.commands.MissingPermissions`
+                - :exc:`~.commands.BotMissingPermissions`
+            - :exc:`~.commands.DisabledCommand`
+            - :exc:`~.commands.CommandInvokeError`
+            - :exc:`~.commands.CommandOnCooldown`

docs/extensions/exception_hierarchy.py

@@ -0,0 +1,27 @@
+from docutils.parsers.rst import Directive
+from docutils.parsers.rst import states, directives
+from docutils.parsers.rst.roles import set_classes
+from docutils import nodes
+from sphinx.locale import _
+
+class exception_hierarchy(nodes.General, nodes.Element):
+    pass
+
+def visit_exception_hierarchy_node(self, node):
+    self.body.append(self.starttag(node, 'div', CLASS='exception-hierarchy-content'))
+
+def depart_exception_hierarchy_node(self, node):
+    self.body.append('</div>\n')
+
+class ExceptionHierarchyDirective(Directive):
+    has_content = True
+
+    def run(self):
+        self.assert_has_content()
+        node = exception_hierarchy('\n'.join(self.content))
+        self.state.nested_parse(self.content, self.content_offset, node)
+        return [node]
+
+def setup(app):
+    app.add_node(exception_hierarchy, html=(visit_exception_hierarchy_node, depart_exception_hierarchy_node))
+    app.add_directive('exception_hierarchy', ExceptionHierarchyDirective)