CI deploy ad5ff8be

server/main.py

@@ -232,9 +232,16 @@ def _error_stream(message: str) -> StreamingResponse:
 if STATIC.is_dir():
     app.mount("/assets", StaticFiles(directory=STATIC / "assets"), name="assets")
 
+    # The bundle's filename carries a content hash, so `index.html` is the only
+    # thing that has to be re-fetched for a deploy to be visible. Cached, it
+    # keeps pointing at the previous bundle for as long as the browser feels
+    # like it -- which reads as "the deploy did nothing", and cost an afternoon
+    # of testing against a build that was no longer there.
+    NO_CACHE = {"Cache-Control": "no-cache, must-revalidate"}
+
     @app.get("/")
     async def index():
-        return FileResponse(STATIC / "index.html")
+        return FileResponse(STATIC / "index.html", headers=NO_CACHE)
 
     @app.get("/{path:path}")
     async def spa(path: str):
@@ -248,4 +255,4 @@ if STATIC.is_dir():
         target = STATIC / path
         if target.is_file():
             return FileResponse(target)
-        return FileResponse(STATIC / "index.html")
+        return FileResponse(STATIC / "index.html", headers=NO_CACHE)

static/index.html

@@ -18,7 +18,7 @@
         font: 12px ui-monospace, SFMono-Regular, Menlo, monospace; color: #c9a227;
       }
     </style>
-    <script type="module" crossorigin src="./assets/index-CPXmKFX8.js"></script>
+    <script type="module" crossorigin src="./assets/index-BZ_QKopz.js"></script>
   </head>
   <body>
     <div id="app"></div>

tests/test_api.py

@@ -110,3 +110,17 @@ def test_a_non_api_path_still_falls_through_to_the_app(client):
     # bare checkout, since CI builds it before the deploy either way.
     r = client.get("/some/client/route")
     assert r.status_code in (200, 404)
+
+
+def test_the_page_is_not_cached(client):
+    """A cached index.html keeps pointing at the previous bundle.
+
+    The assets are content-hashed and may cache forever; the page that names
+    them may not, or a deploy is invisible until the browser feels like
+    re-fetching — which reads as "the deploy did nothing".
+    """
+    for path in ("/", "/anything"):
+        r = client.get(path)
+        if r.status_code != 200:
+            continue
+        assert "no-cache" in r.headers.get("cache-control", "")