Revert "Replace AsgiLifespan with AsgiRunOnFirstRequest, refs #1955"

This reverts commit dc18f62.

datasette/app.py

@@ -69,17 +69,20 @@
     row_sql_params_pks,
 )
 from .utils.asgi import (
+    AsgiLifespan,
+    Base400,
     Forbidden,
     NotFound,
     DatabaseNotFound,
     TableNotFound,
     RowNotFound,
     Request,
     Response,
-    AsgiRunOnFirstRequest,
     asgi_static,
     asgi_send,
     asgi_send_file,
+    asgi_send_html,
+    asgi_send_json,
     asgi_send_redirect,
 )
 from .utils.internal_db import init_internal_db, populate_schema_tables
@@ -1417,7 +1420,7 @@ def app(self):
 
         async def setup_db():
             # First time server starts up, calculate table counts for immutable databases
-            for database in self.databases.values():
+            for dbname, database in self.databases.items():
                 if not database.is_mutable:
                     await database.table_counts(limit=60 * 60 * 1000)
 
@@ -1431,7 +1434,10 @@ async def setup_db():
         )
         if self.setting("trace_debug"):
             asgi = AsgiTracer(asgi)
-        asgi = AsgiRunOnFirstRequest(asgi, on_startup=[setup_db, self.invoke_startup])
+        asgi = AsgiLifespan(
+            asgi,
+            on_startup=setup_db,
+        )
         for wrapper in pm.hook.asgi_wrapper(datasette=self):
             asgi = wrapper(asgi)
         return asgi
@@ -1720,34 +1726,42 @@ def _fix(self, path, avoid_path_rewrites=False):
         return path
 
     async def get(self, path, **kwargs):
+        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.get(self._fix(path), **kwargs)
 
     async def options(self, path, **kwargs):
+        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.options(self._fix(path), **kwargs)
 
     async def head(self, path, **kwargs):
+        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.head(self._fix(path), **kwargs)
 
     async def post(self, path, **kwargs):
+        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.post(self._fix(path), **kwargs)
 
     async def put(self, path, **kwargs):
+        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.put(self._fix(path), **kwargs)
 
     async def patch(self, path, **kwargs):
+        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.patch(self._fix(path), **kwargs)
 
     async def delete(self, path, **kwargs):
+        await self.ds.invoke_startup()
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.delete(self._fix(path), **kwargs)
 
     async def request(self, method, path, **kwargs):
+        await self.ds.invoke_startup()
         avoid_path_rewrites = kwargs.pop("avoid_path_rewrites", None)
         async with httpx.AsyncClient(app=self.app) as client:
             return await client.request(

datasette/utils/asgi.py

@@ -156,6 +156,35 @@ def fake(cls, path_with_query_string, method="GET", scheme="http", url_vars=None
         return cls(scope, None)
 
 
+class AsgiLifespan:
+    def __init__(self, app, on_startup=None, on_shutdown=None):
+        self.app = app
+        on_startup = on_startup or []
+        on_shutdown = on_shutdown or []
+        if not isinstance(on_startup or [], list):
+            on_startup = [on_startup]
+        if not isinstance(on_shutdown or [], list):
+            on_shutdown = [on_shutdown]
+        self.on_startup = on_startup
+        self.on_shutdown = on_shutdown
+
+    async def __call__(self, scope, receive, send):
+        if scope["type"] == "lifespan":
+            while True:
+                message = await receive()
+                if message["type"] == "lifespan.startup":
+                    for fn in self.on_startup:
+                        await fn()
+                    await send({"type": "lifespan.startup.complete"})
+                elif message["type"] == "lifespan.shutdown":
+                    for fn in self.on_shutdown:
+                        await fn()
+                    await send({"type": "lifespan.shutdown.complete"})
+                    return
+        else:
+            await self.app(scope, receive, send)
+
+
 class AsgiStream:
     def __init__(self, stream_fn, status=200, headers=None, content_type="text/plain"):
         self.stream_fn = stream_fn
@@ -420,18 +449,3 @@ async def asgi_send(self, send):
             content_type=self.content_type,
             headers=self.headers,
         )
-
-
-class AsgiRunOnFirstRequest:
-    def __init__(self, asgi, on_startup):
-        assert isinstance(on_startup, list)
-        self.asgi = asgi
-        self.on_startup = on_startup
-        self._started = False
-
-    async def __call__(self, scope, receive, send):
-        if not self._started:
-            self._started = True
-            for hook in self.on_startup:
-                await hook()
-        return await self.asgi(scope, receive, send)

docs/plugin_hooks.rst

@@ -902,14 +902,13 @@ Potential use-cases:
 
 .. note::
 
-   If you are writing :ref:`unit tests <testing_plugins>` for a plugin that uses this hook and doesn't exercise Datasette by sending
-   any simulated requests through it you will need to explicitly call ``await ds.invoke_startup()`` in your tests. An example:
+   If you are writing :ref:`unit tests <testing_plugins>` for a plugin that uses this hook you will need to explicitly call ``await ds.invoke_startup()`` in your tests. An example:
 
    .. code-block:: python
 
         @pytest.mark.asyncio
         async def test_my_plugin():
-            ds = Datasette()
+            ds = Datasette([], metadata={})
             await ds.invoke_startup()
             # Rest of test goes here
 

docs/testing_plugins.rst

@@ -80,7 +80,7 @@ Creating a ``Datasette()`` instance like this as useful shortcut in tests, but t
 
 This method registers any :ref:`plugin_hook_startup` or :ref:`plugin_hook_prepare_jinja2_environment` plugins that might themselves need to make async calls.
 
-If you are using ``await datasette.client.get()`` and similar methods then you don't need to worry about this - Datasette automatically calls ``invoke_startup()`` the first time it handles a request.
+If you are using ``await datasette.client.get()`` and similar methods then you don't need to worry about this - those method calls ensure that ``.invoke_startup()`` has been called for you.
 
 .. _testing_plugins_pdb:
 

tests/test_internals_datasette_client.py

@@ -6,6 +6,7 @@
 
 @pytest_asyncio.fixture
 async def datasette(app_client):
+    await app_client.ds.invoke_startup()
     return app_client.ds