test(host): close Row 9 fanout partition

src/host/fanout.rs

@@ -1038,8 +1038,15 @@ mod tests {
         ));
     }
 
-    #[test]
-    fn eligible_late_arrival_is_positively_captured() {
+    #[derive(Clone, Copy)]
+    enum Row9Scenario {
+        MusicOnly,
+        DifferentDeviceMicrophone,
+        SameDeviceMicrophone,
+        TaintedMonitor,
+    }
+
+    fn assert_row_9_late_arrival(scenario: Row9Scenario, expected_reason: Option<&str>) {
         let mut graph = Graph::new();
         let sink = graph.native_virtual_node("pixelpass_capture_test", MediaRole::Sink, 43);
         graph.port_on_channel(sink, PortDirection::In, false, Some("FL"));
@@ -1049,17 +1056,95 @@ mod tests {
         drive(&mut controller, &graph, &mut links);
         assert!(links.held.is_empty());
 
-        let late = graph.app_node("late", MediaRole::StreamOutput, 44);
-        graph.port_on_channel(late, PortDirection::Out, false, Some("FL"));
-        graph.port_on_channel(late, PortDirection::Out, false, Some("FR"));
+        let firefox_pid = 11_114;
+        let firefox = match scenario {
+            Row9Scenario::MusicOnly => {
+                graph.app_node("firefox-music", MediaRole::StreamOutput, firefox_pid)
+            }
+            Row9Scenario::DifferentDeviceMicrophone => {
+                let speakers = graph.device_node_on("speakers", MediaRole::Sink, GlobalId(700));
+                let microphone =
+                    graph.device_node_on("usb-microphone", MediaRole::Source, GlobalId(701));
+                let call = graph.peerspeak_node("call", 7);
+                let firefox_in =
+                    graph.app_node("firefox-microphone", MediaRole::StreamInput, firefox_pid);
+                graph.link(call, speakers);
+                graph.link(microphone, firefox_in);
+                graph.app_node("firefox-audio", MediaRole::StreamOutput, firefox_pid)
+            }
+            Row9Scenario::SameDeviceMicrophone => {
+                let device = GlobalId(700);
+                let speakers = graph.device_node_on("headset-output", MediaRole::Sink, device);
+                let microphone =
+                    graph.device_node_on("headset-microphone", MediaRole::Source, device);
+                let call = graph.peerspeak_node("call", 7);
+                let firefox_in =
+                    graph.app_node("firefox-microphone", MediaRole::StreamInput, firefox_pid);
+                graph.link(call, speakers);
+                graph.link(microphone, firefox_in);
+                graph.app_node("firefox-audio", MediaRole::StreamOutput, firefox_pid)
+            }
+            Row9Scenario::TaintedMonitor => {
+                let speakers = graph.device_node("speakers", MediaRole::Sink);
+                let call = graph.peerspeak_node("call", 7);
+                let firefox_in =
+                    graph.app_node("firefox-monitor", MediaRole::StreamInput, firefox_pid);
+                graph.link(call, speakers);
+                graph.link(speakers, firefox_in);
+                graph.app_node("firefox-audio", MediaRole::StreamOutput, firefox_pid)
+            }
+        };
+        graph.port_on_channel(firefox, PortDirection::Out, false, Some("FL"));
+        graph.port_on_channel(firefox, PortDirection::Out, false, Some("FR"));
         drive(&mut controller, &graph, &mut links);
-        assert_eq!(links.creates, 2);
-        assert_eq!(
-            controller.states()[&late.serial],
-            StreamCaptureState::Captured
+
+        match expected_reason {
+            None => {
+                assert_eq!(links.creates, 2, "both stereo links must be created");
+                assert_eq!(links.held.len(), 2);
+                assert_eq!(
+                    controller.states()[&firefox.serial],
+                    StreamCaptureState::Captured
+                );
+            }
+            Some(expected_reason) => {
+                assert_eq!(links.creates, 0, "an excluded stream must never be linked");
+                assert!(links.held.is_empty());
+                let StreamCaptureState::Excluded { reason } = controller.states()[&firefox.serial]
+                else {
+                    panic!("the late Firefox stream must be excluded");
+                };
+                assert_eq!(reason.code(), expected_reason);
+            }
+        }
+
+        drive(&mut controller, &graph, &mut links);
+        assert_eq!(links.creates, if expected_reason.is_none() { 2 } else { 0 });
+    }
+
+    #[test]
+    fn row_9a_music_only_late_arrival_is_positively_captured() {
+        assert_row_9_late_arrival(Row9Scenario::MusicOnly, None);
+    }
+
+    #[test]
+    fn row_9b_different_device_microphone_late_arrival_is_positively_captured() {
+        assert_row_9_late_arrival(Row9Scenario::DifferentDeviceMicrophone, None);
+    }
+
+    #[test]
+    fn row_9c_same_device_microphone_late_arrival_is_never_linked() {
+        assert_row_9_late_arrival(
+            Row9Scenario::SameDeviceMicrophone,
+            Some("tainted-owner-bridge"),
         );
     }
 
+    #[test]
+    fn row_9d_tainted_monitor_late_arrival_is_never_linked() {
+        assert_row_9_late_arrival(Row9Scenario::TaintedMonitor, Some("tainted-owner-bridge"));
+    }
+
     #[test]
     fn configured_but_unvalidated_aec_gates_every_mutation() {
         let (graph, app, sink, _) = stereo_graph();