add datastar SSE rendering

tests/test_web.py

@@ -1,13 +1,21 @@
 from __future__ import annotations
 
 import asyncio
+from typing import Any, cast
 
-from repub.web import create_app
+from repub.datastar import RefreshBroker, render_sse_event, render_stream
+from repub.web import (
+    create_app,
+    get_active_jobs,
+    get_refresh_broker,
+    render_dashboard,
+    set_active_jobs,
+)
 
 
 def test_root_get_serves_datastar_shim() -> None:
     async def run() -> None:
-        client = create_app().test_client()
+        client = create_app(enable_demo_refresh=False).test_client()
 
         response = await client.get("/")
         body = await response.get_data(as_text=True)
@@ -30,7 +38,7 @@ def test_root_get_serves_datastar_shim() -> None:
 
 def test_root_get_honors_if_none_match() -> None:
     async def run() -> None:
-        client = create_app().test_client()
+        client = create_app(enable_demo_refresh=False).test_client()
 
         initial = await client.get("/")
         etag = initial.headers["ETag"]
@@ -45,15 +53,86 @@ def test_root_get_honors_if_none_match() -> None:
 
 def test_root_post_serves_morph_component() -> None:
     async def run() -> None:
-        client = create_app().test_client()
+        client = create_app(enable_demo_refresh=False).test_client()
+        async with client.request("/?u=shim", method="POST") as connection:
+            await connection.send_complete()
+            chunk = await asyncio.wait_for(connection.receive(), timeout=1)
+            raw_connection = cast(Any, connection)
 
-        response = await client.post("/?u=shim")
-        body = await response.get_data(as_text=True)
-
-        assert response.status_code == 200
-        assert response.content_type == "text/html; charset=utf-8"
-        assert body.startswith('<main id="morph"')
-        assert "Admin UI" in body
-        assert "All on one page for the v1 spike" not in body
+            assert raw_connection.status_code == 200
+            assert raw_connection.headers["Content-Type"] == "text/event-stream"
+            assert b"event: datastar-patch-elements" in chunk
+            assert b"id: " in chunk
+            assert b'<main id="morph"' in chunk
+            await connection.disconnect()
+
+    asyncio.run(run())
+
+
+def test_render_sse_event_skips_unchanged_view() -> None:
+    async def run() -> None:
+        async def render() -> str:
+            return '<main id="morph">same</main>'
+
+        event_id, event = await render_sse_event(render)
+        repeated_id, repeated_event = await render_sse_event(
+            render, last_event_id=event_id
+        )
+
+        assert repeated_id == event_id
+        assert event is not None
+        assert repeated_event is None
+
+    asyncio.run(run())
+
+
+def test_app_refresh_broker_publishes_events() -> None:
+    async def run() -> None:
+        app = create_app(enable_demo_refresh=False)
+        broker = get_refresh_broker(app)
+        queue = broker.subscribe()
+
+        broker.publish()
+        event = await asyncio.wait_for(queue.get(), timeout=1)
+
+        assert event == "refresh-event"
+        broker.unsubscribe(queue)
+
+    asyncio.run(run())
+
+
+def test_render_stream_yields_on_connect_and_refresh() -> None:
+    async def run() -> None:
+        queue = RefreshBroker().subscribe()
+        renders = 0
+
+        async def render() -> str:
+            nonlocal renders
+            renders += 1
+            return f'<main id="morph">{renders}</main>'
+
+        stream = render_stream(queue, render)
+        first = await anext(stream)
+        await queue.put("refresh-event")
+        second = await anext(stream)
+        await stream.aclose()
+
+        assert "1</main>" in first
+        assert "2</main>" in second
+
+    asyncio.run(run())
+
+
+def test_render_dashboard_uses_active_jobs_from_app_state() -> None:
+    async def run() -> None:
+        app = create_app(enable_demo_refresh=False)
+        assert get_active_jobs(app) == 12
+        set_active_jobs(app, 27)
+
+        async with app.app_context():
+            body = str(await render_dashboard(app))
+
+        assert "27" in body
+        assert "Temporary live demo counter for Datastar refresh testing" in body
 
     asyncio.run(run())