Added asgi_wrapper plugin hook, closes #520

datasette/app.py

@@ -651,9 +651,12 @@ class Datasette:
                 if not database.is_mutable:
                     await database.table_counts(limit=60 * 60 * 1000)
 
-        return AsgiLifespan(
+        asgi = AsgiLifespan(
             AsgiTracer(DatasetteRouter(self, routes)), on_startup=setup_db
         )
+        for wrapper in pm.hook.asgi_wrapper(datasette=self):
+            asgi = wrapper(asgi)
+        return asgi
 
 
 class DatasetteRouter(AsgiRouter):

datasette/hookspecs.py

@@ -5,6 +5,11 @@ hookspec = HookspecMarker("datasette")
 hookimpl = HookimplMarker("datasette")
 
 
+@hookspec
+def asgi_wrapper(datasette):
+    "Returns an ASGI middleware callable to wrap our ASGI application with"
+
+
 @hookspec
 def prepare_connection(conn):
     "Modify SQLite connection in some way e.g. register custom SQL functions"