Integration tests: one copy of each helper

The test files had grown their own copies of the same helpers: prefix()
twelve times, established() seven, an UPDATE builder six, a seventeen
field PeerConfig literal in fifteen places, a timeout constant in twenty
one. Each is in crates/integration-tests/src once now: peer_config() and
TestServer::with_peer for a configured peer, Announcement for building
UPDATEs, established(), the waits (wait_until, wait_for, wait_for_routes,
wait_for_sessions), get_json, and TIMEOUT. A new field on PeerConfig is
one line to add, not fifteen.

TestPeer::recv has a deadline, so a test that gets nothing fails instead
of hanging; is_closed, which read one byte and took a KEEPALIVE for an
open connection, is closed_within and closed_unanswered.

Net 788 lines fewer; every test checks what it did.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

crates/integration-tests/tests/http_api.rs

@@ -3,46 +3,22 @@
 use std::net::Ipv4Addr;
 use std::time::Duration;
 
+use bgp_integration_tests::announcement::announcement;
 use bgp_integration_tests::test_peer::TestPeer;
 use bgp_integration_tests::test_server::TestServer;
-use bgp_packet::message::{
-    AsPathAttribute, CommunitiesPathAttribute, LargeCommunity, Message, NextHopPathAttribute,
-    OriginPathAttribute, PathAttribute, UpdateMessage,
-};
-use bgp_primitives::ip_prefix::IpPrefix;
+use bgp_integration_tests::{TIMEOUT, get_json, prefix};
+use bgp_packet::message::LargeCommunity;
 use bgp_rib::{LocalRoute, LocalRouteAttrs};
 use eyre::Result;
 use serde_json::{Value, json};
 
 const LOCAL_ASN: u32 = 65000;
 const PEER_ASN: u32 = 65001;
-const TIMEOUT: Duration = Duration::from_secs(5);
-
-fn prefix(s: &str) -> IpPrefix {
-    IpPrefix::try_from(s).unwrap()
-}
 
 async fn established_peer(server: &TestServer) -> Result<TestPeer> {
-    let mut peer = TestPeer::connect(server.addr).await?;
-    peer.handshake(PEER_ASN, Ipv4Addr::new(10, 0, 0, 1), 90)
-        .await?;
-    tokio::time::timeout(TIMEOUT, async {
-        while server.registry.list().is_empty() {
-            tokio::time::sleep(Duration::from_millis(10)).await;
-        }
-    })
-    .await?;
-    Ok(peer)
-}
-
-async fn get_json(client: &reqwest::Client, url: &str) -> Result<Value> {
-    Ok(client
-        .get(url)
-        .send()
-        .await?
-        .error_for_status()?
-        .json()
-        .await?)
+    server
+        .established(PEER_ASN, Ipv4Addr::new(10, 0, 0, 1))
+        .await
 }
 
 #[tokio::test]
@@ -155,16 +131,11 @@ async fn test_received_routes_summary() -> Result<()> {
     let client = reqwest::Client::new();
     let mut peer = established_peer(&server).await?;
 
-    peer.send(&Message::Update(UpdateMessage {
-        withdrawn_routes: vec![],
-        path_attributes: vec![
-            PathAttribute::Origin(OriginPathAttribute::IGP),
-            AsPathAttribute::from_asns(vec![PEER_ASN, 65002]),
-            PathAttribute::NextHop(NextHopPathAttribute(Ipv4Addr::new(10, 0, 0, 1))),
-            PathAttribute::Communities(CommunitiesPathAttribute(vec![(65001, 7)])),
-        ],
-        announced_routes: vec![prefix("203.0.113.0/24").into()],
-    }))
+    peer.announce(
+        announcement(&["203.0.113.0/24"], &[PEER_ASN, 65002])
+            .with_next_hop(Ipv4Addr::new(10, 0, 0, 1))
+            .with_communities(&[(65001, 7)]),
+    )
     .await?;
 
     let received = tokio::time::timeout(TIMEOUT, async {