1 files changed, 40 insertions, 1 deletions
diff --git a/packages/meshbay-hub/tests/test_downloads.py b/packages/meshbay-hub/tests/test_downloads.py
index 41d61bf..85bf488 100644
--- a/packages/meshbay-hub/tests/test_downloads.py
+++ b/packages/meshbay-hub/tests/test_downloads.py
@@ -161,6 +161,45 @@ def test_backpressure_is_real(tmp_path):
     src = DOWNLOADS.read_text()
     fn = src[src.index("export async function openStreamedDownload"):]
     assert "new TransformStream()" in fn
-    assert "[readable]" in fn, "the readable half must be transferred, not copied"
+    # The transfer list may carry more than the stream — a reply port rides
+    # along now — so this asserts that `readable` is transferred, not the exact
+    # shape of the list.
+    transfer = fn[fn.index("worker.postMessage("):]
+    transfer = transfer[transfer.index("["):transfer.index("]") + 1]
+    assert "readable" in transfer, "the readable half must be transferred, not copied"
     assert "writer.write(bytes)" in fn
     assert "return null" in fn, "a browser that cannot transfer streams must say so"
+
+
+def test_the_streamed_path_gives_up_rather_than_blocking_for_ever():
+    """Reported 2026-08-16: a download frozen at exactly one chunk.
+
+    The writable half applies real backpressure, which is the whole point — and
+    the trap. If nothing ever reads the readable half, `writer.write()` waits
+    for room that never comes, and the transfer stops dead after the stream's
+    internal queue fills. Two ways that happens on a phone: the page is not yet
+    *controlled* by the worker, so the iframe's request is never handed to its
+    fetch handler; or the browser refuses a download started from a hidden
+    iframe. Both are silent.
+
+    So the worker confirms that it actually answered, and this path reports
+    failure instead of returning a sink nobody drains.
+    """
+    src = DOWNLOADS.read_text()
+    fn = src[src.index("export async function openStreamedDownload"):]
+    assert "mbdl-serving" in fn, "the worker has to confirm it served the request"
+    assert "Promise.race" in fn, "the confirmation needs a deadline"
+    assert "writable.abort" in fn, "give up cleanly so the caller can fall back"
+
+    sw = (DOWNLOADS.parent / "sw.js").read_text()
+    assert "mbdl-serving" in sw, "and the worker has to send that confirmation"
+
+
+def test_an_uncontrolled_page_is_not_treated_as_ready():
+    """`registration.active` says a worker exists, not that it will see our fetch."""
+    src = DOWNLOADS.read_text()
+    fn = src[src.index("async function serviceWorker()"):]
+    fn = fn[:fn.index("\n}")]
+    assert "navigator.serviceWorker.controller" in fn
+    assert "controllerchange" in fn, (
+        "control can arrive a tick after registration; waiting beats refusing")