fix(tests): add comprehensive unit and async tests across Rust crates and TypeScript runtime

rust/crates/remoteingress-bin/src/main.rs

@@ -369,3 +369,58 @@ async fn handle_request(
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_ipc_request_deserialize() {
+        let json = r#"{"id": "1", "method": "ping", "params": {}}"#;
+        let req: IpcRequest = serde_json::from_str(json).unwrap();
+        assert_eq!(req.id, "1");
+        assert_eq!(req.method, "ping");
+        assert!(req.params.is_object());
+    }
+
+    #[test]
+    fn test_ipc_response_skip_error_when_none() {
+        let resp = IpcResponse {
+            id: "1".to_string(),
+            success: true,
+            result: Some(serde_json::json!({"pong": true})),
+            error: None,
+        };
+        let json = serde_json::to_value(&resp).unwrap();
+        assert_eq!(json["id"], "1");
+        assert_eq!(json["success"], true);
+        assert_eq!(json["result"]["pong"], true);
+        assert!(json.get("error").is_none());
+    }
+
+    #[test]
+    fn test_ipc_response_skip_result_when_none() {
+        let resp = IpcResponse {
+            id: "2".to_string(),
+            success: false,
+            result: None,
+            error: Some("something failed".to_string()),
+        };
+        let json = serde_json::to_value(&resp).unwrap();
+        assert_eq!(json["id"], "2");
+        assert_eq!(json["success"], false);
+        assert_eq!(json["error"], "something failed");
+        assert!(json.get("result").is_none());
+    }
+
+    #[test]
+    fn test_ipc_event_serialize() {
+        let evt = IpcEvent {
+            event: "ready".to_string(),
+            data: serde_json::json!({"version": "2.0.0"}),
+        };
+        let json = serde_json::to_value(&evt).unwrap();
+        assert_eq!(json["event"], "ready");
+        assert_eq!(json["data"]["version"], "2.0.0");
+    }
+}

rust/crates/remoteingress-core/src/edge.rs

@@ -544,6 +544,186 @@ async fn handle_client_connection(
     let _ = edge_id; // used for logging context
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // --- Serde tests ---
+
+    #[test]
+    fn test_edge_config_deserialize_camel_case() {
+        let json = r#"{
+            "hubHost": "hub.example.com",
+            "hubPort": 8443,
+            "edgeId": "edge-1",
+            "secret": "my-secret"
+        }"#;
+        let config: EdgeConfig = serde_json::from_str(json).unwrap();
+        assert_eq!(config.hub_host, "hub.example.com");
+        assert_eq!(config.hub_port, 8443);
+        assert_eq!(config.edge_id, "edge-1");
+        assert_eq!(config.secret, "my-secret");
+    }
+
+    #[test]
+    fn test_edge_config_serialize_roundtrip() {
+        let config = EdgeConfig {
+            hub_host: "host.test".to_string(),
+            hub_port: 9999,
+            edge_id: "e1".to_string(),
+            secret: "sec".to_string(),
+        };
+        let json = serde_json::to_string(&config).unwrap();
+        let back: EdgeConfig = serde_json::from_str(&json).unwrap();
+        assert_eq!(back.hub_host, config.hub_host);
+        assert_eq!(back.hub_port, config.hub_port);
+        assert_eq!(back.edge_id, config.edge_id);
+        assert_eq!(back.secret, config.secret);
+    }
+
+    #[test]
+    fn test_handshake_config_deserialize_all_fields() {
+        let json = r#"{"listenPorts": [80, 443], "stunIntervalSecs": 120}"#;
+        let hc: HandshakeConfig = serde_json::from_str(json).unwrap();
+        assert_eq!(hc.listen_ports, vec![80, 443]);
+        assert_eq!(hc.stun_interval_secs, 120);
+    }
+
+    #[test]
+    fn test_handshake_config_default_stun_interval() {
+        let json = r#"{"listenPorts": [443]}"#;
+        let hc: HandshakeConfig = serde_json::from_str(json).unwrap();
+        assert_eq!(hc.listen_ports, vec![443]);
+        assert_eq!(hc.stun_interval_secs, 300);
+    }
+
+    #[test]
+    fn test_config_update_deserialize() {
+        let json = r#"{"listenPorts": [8080, 9090]}"#;
+        let update: ConfigUpdate = serde_json::from_str(json).unwrap();
+        assert_eq!(update.listen_ports, vec![8080, 9090]);
+    }
+
+    #[test]
+    fn test_edge_status_serialize() {
+        let status = EdgeStatus {
+            running: true,
+            connected: true,
+            public_ip: Some("1.2.3.4".to_string()),
+            active_streams: 5,
+            listen_ports: vec![443],
+        };
+        let json = serde_json::to_value(&status).unwrap();
+        assert_eq!(json["running"], true);
+        assert_eq!(json["connected"], true);
+        assert_eq!(json["publicIp"], "1.2.3.4");
+        assert_eq!(json["activeStreams"], 5);
+        assert_eq!(json["listenPorts"], serde_json::json!([443]));
+    }
+
+    #[test]
+    fn test_edge_status_serialize_none_ip() {
+        let status = EdgeStatus {
+            running: false,
+            connected: false,
+            public_ip: None,
+            active_streams: 0,
+            listen_ports: vec![],
+        };
+        let json = serde_json::to_value(&status).unwrap();
+        assert!(json["publicIp"].is_null());
+    }
+
+    #[test]
+    fn test_edge_event_tunnel_connected() {
+        let event = EdgeEvent::TunnelConnected;
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "tunnelConnected");
+    }
+
+    #[test]
+    fn test_edge_event_tunnel_disconnected() {
+        let event = EdgeEvent::TunnelDisconnected;
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "tunnelDisconnected");
+    }
+
+    #[test]
+    fn test_edge_event_public_ip_discovered() {
+        let event = EdgeEvent::PublicIpDiscovered {
+            ip: "203.0.113.1".to_string(),
+        };
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "publicIpDiscovered");
+        assert_eq!(json["ip"], "203.0.113.1");
+    }
+
+    #[test]
+    fn test_edge_event_ports_assigned() {
+        let event = EdgeEvent::PortsAssigned {
+            listen_ports: vec![443, 8080],
+        };
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "portsAssigned");
+        assert_eq!(json["listenPorts"], serde_json::json!([443, 8080]));
+    }
+
+    #[test]
+    fn test_edge_event_ports_updated() {
+        let event = EdgeEvent::PortsUpdated {
+            listen_ports: vec![9090],
+        };
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "portsUpdated");
+        assert_eq!(json["listenPorts"], serde_json::json!([9090]));
+    }
+
+    // --- Async tests ---
+
+    #[tokio::test]
+    async fn test_tunnel_edge_new_get_status() {
+        let edge = TunnelEdge::new(EdgeConfig {
+            hub_host: "localhost".to_string(),
+            hub_port: 8443,
+            edge_id: "test-edge".to_string(),
+            secret: "test-secret".to_string(),
+        });
+        let status = edge.get_status().await;
+        assert!(!status.running);
+        assert!(!status.connected);
+        assert!(status.public_ip.is_none());
+        assert_eq!(status.active_streams, 0);
+        assert!(status.listen_ports.is_empty());
+    }
+
+    #[tokio::test]
+    async fn test_tunnel_edge_take_event_rx() {
+        let edge = TunnelEdge::new(EdgeConfig {
+            hub_host: "localhost".to_string(),
+            hub_port: 8443,
+            edge_id: "e".to_string(),
+            secret: "s".to_string(),
+        });
+        let rx1 = edge.take_event_rx().await;
+        assert!(rx1.is_some());
+        let rx2 = edge.take_event_rx().await;
+        assert!(rx2.is_none());
+    }
+
+    #[tokio::test]
+    async fn test_tunnel_edge_stop_without_start() {
+        let edge = TunnelEdge::new(EdgeConfig {
+            hub_host: "localhost".to_string(),
+            hub_port: 8443,
+            edge_id: "e".to_string(),
+            secret: "s".to_string(),
+        });
+        edge.stop().await; // should not panic
+        let status = edge.get_status().await;
+        assert!(!status.running);
+    }
+}
+
 /// TLS certificate verifier that accepts any certificate (auth is via shared secret).
 #[derive(Debug)]
 struct NoCertVerifier;

rust/crates/remoteingress-core/src/hub.rs

@@ -549,3 +549,210 @@ fn constant_time_eq(a: &[u8], b: &[u8]) -> bool {
     }
     diff == 0
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    // --- constant_time_eq tests ---
+
+    #[test]
+    fn test_constant_time_eq_equal() {
+        assert!(constant_time_eq(b"hello", b"hello"));
+    }
+
+    #[test]
+    fn test_constant_time_eq_different_content() {
+        assert!(!constant_time_eq(b"hello", b"world"));
+    }
+
+    #[test]
+    fn test_constant_time_eq_different_lengths() {
+        assert!(!constant_time_eq(b"short", b"longer"));
+    }
+
+    #[test]
+    fn test_constant_time_eq_both_empty() {
+        assert!(constant_time_eq(b"", b""));
+    }
+
+    #[test]
+    fn test_constant_time_eq_one_empty() {
+        assert!(!constant_time_eq(b"", b"notempty"));
+    }
+
+    #[test]
+    fn test_constant_time_eq_single_bit_difference() {
+        // 'A' = 0x41, 'a' = 0x61 — differ by one bit
+        assert!(!constant_time_eq(b"A", b"a"));
+    }
+
+    // --- parse_dest_port_from_proxy tests ---
+
+    #[test]
+    fn test_parse_dest_port_443() {
+        let header = "PROXY TCP4 1.2.3.4 5.6.7.8 12345 443\r\n";
+        assert_eq!(parse_dest_port_from_proxy(header), Some(443));
+    }
+
+    #[test]
+    fn test_parse_dest_port_80() {
+        let header = "PROXY TCP4 10.0.0.1 10.0.0.2 54321 80\r\n";
+        assert_eq!(parse_dest_port_from_proxy(header), Some(80));
+    }
+
+    #[test]
+    fn test_parse_dest_port_65535() {
+        let header = "PROXY TCP4 10.0.0.1 10.0.0.2 1 65535\r\n";
+        assert_eq!(parse_dest_port_from_proxy(header), Some(65535));
+    }
+
+    #[test]
+    fn test_parse_dest_port_too_few_fields() {
+        let header = "PROXY TCP4 1.2.3.4";
+        assert_eq!(parse_dest_port_from_proxy(header), None);
+    }
+
+    #[test]
+    fn test_parse_dest_port_empty_string() {
+        assert_eq!(parse_dest_port_from_proxy(""), None);
+    }
+
+    #[test]
+    fn test_parse_dest_port_non_numeric() {
+        let header = "PROXY TCP4 1.2.3.4 5.6.7.8 12345 abc\r\n";
+        assert_eq!(parse_dest_port_from_proxy(header), None);
+    }
+
+    // --- Serde tests ---
+
+    #[test]
+    fn test_allowed_edge_deserialize_all_fields() {
+        let json = r#"{
+            "id": "edge-1",
+            "secret": "s3cret",
+            "listenPorts": [443, 8080],
+            "stunIntervalSecs": 120
+        }"#;
+        let edge: AllowedEdge = serde_json::from_str(json).unwrap();
+        assert_eq!(edge.id, "edge-1");
+        assert_eq!(edge.secret, "s3cret");
+        assert_eq!(edge.listen_ports, vec![443, 8080]);
+        assert_eq!(edge.stun_interval_secs, Some(120));
+    }
+
+    #[test]
+    fn test_allowed_edge_deserialize_with_defaults() {
+        let json = r#"{"id": "edge-2", "secret": "key"}"#;
+        let edge: AllowedEdge = serde_json::from_str(json).unwrap();
+        assert_eq!(edge.id, "edge-2");
+        assert_eq!(edge.secret, "key");
+        assert!(edge.listen_ports.is_empty());
+        assert_eq!(edge.stun_interval_secs, None);
+    }
+
+    #[test]
+    fn test_handshake_response_serializes_camel_case() {
+        let resp = HandshakeResponse {
+            listen_ports: vec![443, 8080],
+            stun_interval_secs: 300,
+        };
+        let json = serde_json::to_value(&resp).unwrap();
+        assert_eq!(json["listenPorts"], serde_json::json!([443, 8080]));
+        assert_eq!(json["stunIntervalSecs"], 300);
+        // Ensure snake_case keys are NOT present
+        assert!(json.get("listen_ports").is_none());
+        assert!(json.get("stun_interval_secs").is_none());
+    }
+
+    #[test]
+    fn test_edge_config_update_serializes_camel_case() {
+        let update = EdgeConfigUpdate {
+            listen_ports: vec![80, 443],
+        };
+        let json = serde_json::to_value(&update).unwrap();
+        assert_eq!(json["listenPorts"], serde_json::json!([80, 443]));
+        assert!(json.get("listen_ports").is_none());
+    }
+
+    #[test]
+    fn test_hub_config_default() {
+        let config = HubConfig::default();
+        assert_eq!(config.tunnel_port, 8443);
+        assert_eq!(config.target_host, Some("127.0.0.1".to_string()));
+        assert!(config.tls_cert_pem.is_none());
+        assert!(config.tls_key_pem.is_none());
+    }
+
+    #[test]
+    fn test_hub_event_edge_connected_serialize() {
+        let event = HubEvent::EdgeConnected {
+            edge_id: "edge-1".to_string(),
+        };
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "edgeConnected");
+        assert_eq!(json["edgeId"], "edge-1");
+    }
+
+    #[test]
+    fn test_hub_event_edge_disconnected_serialize() {
+        let event = HubEvent::EdgeDisconnected {
+            edge_id: "edge-2".to_string(),
+        };
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "edgeDisconnected");
+        assert_eq!(json["edgeId"], "edge-2");
+    }
+
+    #[test]
+    fn test_hub_event_stream_opened_serialize() {
+        let event = HubEvent::StreamOpened {
+            edge_id: "e".to_string(),
+            stream_id: 42,
+        };
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "streamOpened");
+        assert_eq!(json["edgeId"], "e");
+        assert_eq!(json["streamId"], 42);
+    }
+
+    #[test]
+    fn test_hub_event_stream_closed_serialize() {
+        let event = HubEvent::StreamClosed {
+            edge_id: "e".to_string(),
+            stream_id: 7,
+        };
+        let json = serde_json::to_value(&event).unwrap();
+        assert_eq!(json["type"], "streamClosed");
+        assert_eq!(json["edgeId"], "e");
+        assert_eq!(json["streamId"], 7);
+    }
+
+    // --- Async tests ---
+
+    #[tokio::test]
+    async fn test_tunnel_hub_new_get_status() {
+        let hub = TunnelHub::new(HubConfig::default());
+        let status = hub.get_status().await;
+        assert!(!status.running);
+        assert!(status.connected_edges.is_empty());
+        assert_eq!(status.tunnel_port, 8443);
+    }
+
+    #[tokio::test]
+    async fn test_tunnel_hub_take_event_rx() {
+        let hub = TunnelHub::new(HubConfig::default());
+        let rx1 = hub.take_event_rx().await;
+        assert!(rx1.is_some());
+        let rx2 = hub.take_event_rx().await;
+        assert!(rx2.is_none());
+    }
+
+    #[tokio::test]
+    async fn test_tunnel_hub_stop_without_start() {
+        let hub = TunnelHub::new(HubConfig::default());
+        hub.stop().await; // should not panic
+        let status = hub.get_status().await;
+        assert!(!status.running);
+    }
+}

rust/crates/remoteingress-core/src/stun.rs

@@ -121,6 +121,133 @@ fn parse_stun_response(data: &[u8], _txn_id: &[u8; 12]) -> Option<String> {
     None
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Build a synthetic STUN Binding Response with given attributes.
+    fn build_stun_response(attrs: &[(u16, &[u8])]) -> Vec<u8> {
+        let mut attrs_bytes = Vec::new();
+        for &(attr_type, attr_data) in attrs {
+            attrs_bytes.extend_from_slice(&attr_type.to_be_bytes());
+            attrs_bytes.extend_from_slice(&(attr_data.len() as u16).to_be_bytes());
+            attrs_bytes.extend_from_slice(attr_data);
+            // Pad to 4-byte boundary
+            let pad = (4 - (attr_data.len() % 4)) % 4;
+            attrs_bytes.extend(std::iter::repeat(0u8).take(pad));
+        }
+
+        let mut response = Vec::new();
+        // msg_type = 0x0101 (Binding Response)
+        response.extend_from_slice(&0x0101u16.to_be_bytes());
+        // message length
+        response.extend_from_slice(&(attrs_bytes.len() as u16).to_be_bytes());
+        // magic cookie
+        response.extend_from_slice(&STUN_MAGIC_COOKIE.to_be_bytes());
+        // transaction ID (12 bytes)
+        response.extend_from_slice(&[0u8; 12]);
+        // attributes
+        response.extend_from_slice(&attrs_bytes);
+        response
+    }
+
+    #[test]
+    fn test_xor_mapped_address_ipv4() {
+        // IP 203.0.113.1 = 0xCB007101, XOR'd with magic 0x2112A442 = 0xEA12D543
+        let attr_data: [u8; 8] = [
+            0x00, 0x01, // reserved + family (IPv4)
+            0x11, 0x2B, // port XOR'd with 0x2112 (port 0x3039 = 12345)
+            0xEA, 0x12, 0xD5, 0x43, // IP XOR'd
+        ];
+        let data = build_stun_response(&[(ATTR_XOR_MAPPED_ADDRESS, &attr_data)]);
+        let txn_id = [0u8; 12];
+        let result = parse_stun_response(&data, &txn_id);
+        assert_eq!(result, Some("203.0.113.1".to_string()));
+    }
+
+    #[test]
+    fn test_mapped_address_fallback_ipv4() {
+        // IP 192.168.1.1 = 0xC0A80101 (no XOR)
+        let attr_data: [u8; 8] = [
+            0x00, 0x01, // reserved + family (IPv4)
+            0x00, 0x50, // port 80
+            0xC0, 0xA8, 0x01, 0x01, // IP
+        ];
+        let data = build_stun_response(&[(ATTR_MAPPED_ADDRESS, &attr_data)]);
+        let txn_id = [0u8; 12];
+        let result = parse_stun_response(&data, &txn_id);
+        assert_eq!(result, Some("192.168.1.1".to_string()));
+    }
+
+    #[test]
+    fn test_response_too_short() {
+        let data = vec![0u8; 19]; // < 20 bytes
+        let txn_id = [0u8; 12];
+        assert_eq!(parse_stun_response(&data, &txn_id), None);
+    }
+
+    #[test]
+    fn test_wrong_msg_type() {
+        // Build with correct helper then overwrite msg_type to 0x0001 (Binding Request)
+        let mut data = build_stun_response(&[]);
+        data[0] = 0x00;
+        data[1] = 0x01;
+        let txn_id = [0u8; 12];
+        assert_eq!(parse_stun_response(&data, &txn_id), None);
+    }
+
+    #[test]
+    fn test_no_mapped_address_attributes() {
+        // Valid response with no attributes
+        let data = build_stun_response(&[]);
+        let txn_id = [0u8; 12];
+        assert_eq!(parse_stun_response(&data, &txn_id), None);
+    }
+
+    #[test]
+    fn test_xor_preferred_over_mapped() {
+        // XOR gives 203.0.113.1, MAPPED gives 192.168.1.1
+        let xor_data: [u8; 8] = [
+            0x00, 0x01,
+            0x11, 0x2B,
+            0xEA, 0x12, 0xD5, 0x43,
+        ];
+        let mapped_data: [u8; 8] = [
+            0x00, 0x01,
+            0x00, 0x50,
+            0xC0, 0xA8, 0x01, 0x01,
+        ];
+        // XOR listed first — should be preferred
+        let data = build_stun_response(&[
+            (ATTR_XOR_MAPPED_ADDRESS, &xor_data),
+            (ATTR_MAPPED_ADDRESS, &mapped_data),
+        ]);
+        let txn_id = [0u8; 12];
+        let result = parse_stun_response(&data, &txn_id);
+        assert_eq!(result, Some("203.0.113.1".to_string()));
+    }
+
+    #[test]
+    fn test_truncated_attribute_data() {
+        // Attribute claims 8 bytes but only 4 are present
+        let mut data = build_stun_response(&[]);
+        // Manually append a truncated XOR_MAPPED_ADDRESS attribute
+        let attr_type = ATTR_XOR_MAPPED_ADDRESS.to_be_bytes();
+        let attr_len = 8u16.to_be_bytes(); // claims 8 bytes
+        let truncated = [0x00, 0x01, 0x11, 0x2B]; // only 4 bytes
+        // Update message length
+        let new_msg_len = (attr_type.len() + attr_len.len() + truncated.len()) as u16;
+        data[2..4].copy_from_slice(&new_msg_len.to_be_bytes());
+        data.extend_from_slice(&attr_type);
+        data.extend_from_slice(&attr_len);
+        data.extend_from_slice(&truncated);
+
+        let txn_id = [0u8; 12];
+        // Should return None, not panic
+        assert_eq!(parse_stun_response(&data, &txn_id), None);
+    }
+}
+
 /// Generate 12 random bytes for transaction ID.
 fn rand_bytes() -> [u8; 12] {
     let mut bytes = [0u8; 12];

rust/crates/remoteingress-protocol/src/lib.rs

@@ -170,4 +170,127 @@ mod tests {
         // EOF
         assert!(reader.next_frame().await.unwrap().is_none());
     }
+
+    #[test]
+    fn test_encode_frame_config_type() {
+        let payload = b"{\"listenPorts\":[443]}";
+        let encoded = encode_frame(0, FRAME_CONFIG, payload);
+        assert_eq!(encoded[4], FRAME_CONFIG);
+        assert_eq!(&encoded[0..4], &0u32.to_be_bytes());
+        assert_eq!(&encoded[9..], payload.as_slice());
+    }
+
+    #[test]
+    fn test_encode_frame_data_back_type() {
+        let payload = b"response data";
+        let encoded = encode_frame(7, FRAME_DATA_BACK, payload);
+        assert_eq!(encoded[4], FRAME_DATA_BACK);
+        assert_eq!(&encoded[0..4], &7u32.to_be_bytes());
+        assert_eq!(&encoded[5..9], &(payload.len() as u32).to_be_bytes());
+        assert_eq!(&encoded[9..], payload.as_slice());
+    }
+
+    #[test]
+    fn test_encode_frame_close_back_type() {
+        let encoded = encode_frame(99, FRAME_CLOSE_BACK, &[]);
+        assert_eq!(encoded[4], FRAME_CLOSE_BACK);
+        assert_eq!(&encoded[0..4], &99u32.to_be_bytes());
+        assert_eq!(&encoded[5..9], &0u32.to_be_bytes());
+        assert_eq!(encoded.len(), FRAME_HEADER_SIZE);
+    }
+
+    #[test]
+    fn test_encode_frame_large_stream_id() {
+        let encoded = encode_frame(u32::MAX, FRAME_DATA, b"x");
+        assert_eq!(&encoded[0..4], &u32::MAX.to_be_bytes());
+        assert_eq!(encoded[4], FRAME_DATA);
+        assert_eq!(&encoded[5..9], &1u32.to_be_bytes());
+        assert_eq!(encoded[9], b'x');
+    }
+
+    #[tokio::test]
+    async fn test_frame_reader_max_payload_rejection() {
+        let mut data = Vec::new();
+        data.extend_from_slice(&1u32.to_be_bytes());
+        data.push(FRAME_DATA);
+        data.extend_from_slice(&(MAX_PAYLOAD_SIZE + 1).to_be_bytes());
+
+        let cursor = std::io::Cursor::new(data);
+        let mut reader = FrameReader::new(cursor);
+
+        let result = reader.next_frame().await;
+        assert!(result.is_err());
+        let err = result.unwrap_err();
+        assert_eq!(err.kind(), std::io::ErrorKind::InvalidData);
+    }
+
+    #[tokio::test]
+    async fn test_frame_reader_eof_mid_header() {
+        // Only 5 bytes — not enough for a 9-byte header
+        let data = vec![0u8; 5];
+        let cursor = std::io::Cursor::new(data);
+        let mut reader = FrameReader::new(cursor);
+
+        // Should return Ok(None) on partial header EOF
+        let result = reader.next_frame().await;
+        assert!(result.unwrap().is_none());
+    }
+
+    #[tokio::test]
+    async fn test_frame_reader_eof_mid_payload() {
+        // Full header claiming 100 bytes of payload, but only 10 bytes present
+        let mut data = Vec::new();
+        data.extend_from_slice(&1u32.to_be_bytes());
+        data.push(FRAME_DATA);
+        data.extend_from_slice(&100u32.to_be_bytes());
+        data.extend_from_slice(&[0xAB; 10]);
+
+        let cursor = std::io::Cursor::new(data);
+        let mut reader = FrameReader::new(cursor);
+
+        let result = reader.next_frame().await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn test_frame_reader_all_frame_types() {
+        let types = [
+            FRAME_OPEN,
+            FRAME_DATA,
+            FRAME_CLOSE,
+            FRAME_DATA_BACK,
+            FRAME_CLOSE_BACK,
+            FRAME_CONFIG,
+        ];
+
+        let mut data = Vec::new();
+        for (i, &ft) in types.iter().enumerate() {
+            let payload = format!("payload_{}", i);
+            data.extend_from_slice(&encode_frame(i as u32, ft, payload.as_bytes()));
+        }
+
+        let cursor = std::io::Cursor::new(data);
+        let mut reader = FrameReader::new(cursor);
+
+        for (i, &ft) in types.iter().enumerate() {
+            let frame = reader.next_frame().await.unwrap().unwrap();
+            assert_eq!(frame.stream_id, i as u32);
+            assert_eq!(frame.frame_type, ft);
+            assert_eq!(frame.payload, format!("payload_{}", i).as_bytes());
+        }
+
+        assert!(reader.next_frame().await.unwrap().is_none());
+    }
+
+    #[tokio::test]
+    async fn test_frame_reader_zero_length_payload() {
+        let data = encode_frame(42, FRAME_CLOSE, &[]);
+        let cursor = std::io::Cursor::new(data);
+        let mut reader = FrameReader::new(cursor);
+
+        let frame = reader.next_frame().await.unwrap().unwrap();
+        assert_eq!(frame.stream_id, 42);
+        assert_eq!(frame.frame_type, FRAME_CLOSE);
+        assert!(frame.payload.is_empty());
+    }
 }