From a8bcafc1775c8a8655b365ae22a3d64f6361c74a Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Sun, 28 Jun 2020 13:45:17 -0700
Subject: [PATCH] Refactored out AsgiRouter, refs #870

---
 datasette/app.py        | 34 ++++++++++++++++++++++-----
 datasette/utils/asgi.py | 52 -----------------------------------------
 datasette/views/base.py |  1 -
 3 files changed, 28 insertions(+), 59 deletions(-)

diff --git a/datasette/app.py b/datasette/app.py
index 0437a75b..bff01bc1 100644
--- a/datasette/app.py
+++ b/datasette/app.py
@@ -25,7 +25,7 @@ from jinja2.environment import Template
 from jinja2.exceptions import TemplateNotFound
 import uvicorn
 
-from .views.base import DatasetteError, ureg, AsgiRouter
+from .views.base import DatasetteError, ureg
 from .views.database import DatabaseDownload, DatabaseView
 from .views.index import IndexView
 from .views.special import (
@@ -902,10 +902,23 @@ class Datasette:
         return asgi
 
 
-class DatasetteRouter(AsgiRouter):
+class DatasetteRouter:
     def __init__(self, datasette, routes):
         self.ds = datasette
-        super().__init__(routes)
+        routes = routes or []
+        self.routes = [
+            # Compile any strings to regular expressions
+            ((re.compile(pattern) if isinstance(pattern, str) else pattern), view)
+            for pattern, view in routes
+        ]
+
+    async def __call__(self, scope, receive, send):
+        # Because we care about "foo/bar" v.s. "foo%2Fbar" we decode raw_path ourselves
+        path = scope["path"]
+        raw_path = scope.get("raw_path")
+        if raw_path:
+            path = raw_path.decode("ascii")
+        return await self.route_path(scope, receive, send, path)
 
     async def route_path(self, scope, receive, send, path):
         # Strip off base_url if present before routing
@@ -933,9 +946,18 @@ class DatasetteRouter(AsgiRouter):
             if actor:
                 break
         scope_modifications["actor"] = actor or default_actor
-        return await super().route_path(
-            dict(scope, **scope_modifications), receive, send, path
-        )
+        scope = dict(scope, **scope_modifications)
+        for regex, view in self.routes:
+            match = regex.match(path)
+            if match is not None:
+                new_scope = dict(scope, url_route={"kwargs": match.groupdict()})
+                try:
+                    return await view(new_scope, receive, send)
+                except NotFound as exception:
+                    return await self.handle_404(scope, receive, send, exception)
+                except Exception as exception:
+                    return await self.handle_500(scope, receive, send, exception)
+        return await self.handle_404(scope, receive, send)
 
     async def handle_404(self, scope, receive, send, exception=None):
         # If URL has a trailing slash, redirect to URL without it
diff --git a/datasette/utils/asgi.py b/datasette/utils/asgi.py
index 5a152570..615bc0ab 100644
--- a/datasette/utils/asgi.py
+++ b/datasette/utils/asgi.py
@@ -118,58 +118,6 @@ class Request:
         return cls(scope, None)
 
 
-class AsgiRouter:
-    def __init__(self, routes=None):
-        routes = routes or []
-        self.routes = [
-            # Compile any strings to regular expressions
-            ((re.compile(pattern) if isinstance(pattern, str) else pattern), view)
-            for pattern, view in routes
-        ]
-
-    async def __call__(self, scope, receive, send):
-        # Because we care about "foo/bar" v.s. "foo%2Fbar" we decode raw_path ourselves
-        path = scope["path"]
-        raw_path = scope.get("raw_path")
-        if raw_path:
-            path = raw_path.decode("ascii")
-        return await self.route_path(scope, receive, send, path)
-
-    async def route_path(self, scope, receive, send, path):
-        for regex, view in self.routes:
-            match = regex.match(path)
-            if match is not None:
-                new_scope = dict(scope, url_route={"kwargs": match.groupdict()})
-                try:
-                    return await view(new_scope, receive, send)
-                except NotFound as exception:
-                    return await self.handle_404(scope, receive, send, exception)
-                except Exception as exception:
-                    return await self.handle_500(scope, receive, send, exception)
-        return await self.handle_404(scope, receive, send)
-
-    async def handle_404(self, scope, receive, send, exception=None):
-        await send(
-            {
-                "type": "http.response.start",
-                "status": 404,
-                "headers": [[b"content-type", b"text/html; charset=utf-8"]],
-            }
-        )
-        await send({"type": "http.response.body", "body": b"<h1>404</h1>"})
-
-    async def handle_500(self, scope, receive, send, exception):
-        await send(
-            {
-                "type": "http.response.start",
-                "status": 404,
-                "headers": [[b"content-type", b"text/html; charset=utf-8"]],
-            }
-        )
-        html = "<h1>500</h1><pre{}></pre>".format(escape(repr(exception)))
-        await send({"type": "http.response.body", "body": html.encode("utf-8")})
-
-
 class AsgiLifespan:
     def __init__(self, app, on_startup=None, on_shutdown=None):
         self.app = app
diff --git a/datasette/views/base.py b/datasette/views/base.py
index f14e6d3a..821a6f0e 100644
--- a/datasette/views/base.py
+++ b/datasette/views/base.py
@@ -27,7 +27,6 @@ from datasette.utils import (
 from datasette.utils.asgi import (
     AsgiStream,
     AsgiWriter,
-    AsgiRouter,
     AsgiView,
     Forbidden,
     NotFound,