E2E Test: data channel send/receive test.

Author: cloudwebrtc

.github/workflows/tests.yml

@@ -128,14 +128,14 @@ jobs:
           LIVEKIT_API_SECRET: ${{ secrets.LIVEKIT_API_SECRET }}
         run: |
           source .test-venv/bin/activate
-          pytest tests/
+          pytest tests/ livekit-rtc/tests/
 
       - name: Run tests (Windows)
         if: runner.os == 'Windows'
         env:
           LIVEKIT_URL: ${{ secrets.LIVEKIT_URL }}
           LIVEKIT_API_KEY: ${{ secrets.LIVEKIT_API_KEY }}
           LIVEKIT_API_SECRET: ${{ secrets.LIVEKIT_API_SECRET }}
-        run: .test-venv\Scripts\python.exe -m pytest tests/
+        run: .test-venv\Scripts\python.exe -m pytest tests/ livekit-rtc/tests/
         shell: pwsh
 

livekit-rtc/tests/test_dc.py

@@ -0,0 +1,373 @@
+"""End-to-end Test for data-channel scenarios.
+
+Covers one-to-one delivery, broadcasting to all, topic filtering, and targeted
+delivery via `destination_identities`.
+
+Requires the following environment variables to run:
+    LIVEKIT_URL
+    LIVEKIT_API_KEY
+    LIVEKIT_API_SECRET
+"""
+
+from __future__ import annotations
+
+import asyncio
+import os
+import uuid
+from typing import Callable, Optional
+
+import pytest
+
+from livekit import api, rtc
+from livekit.rtc.room import EventTypes
+
+
+WAIT_TIMEOUT = 20.0
+WAIT_INTERVAL = 0.1
+
+
+def skip_if_no_credentials():
+    required_vars = ["LIVEKIT_URL", "LIVEKIT_API_KEY", "LIVEKIT_API_SECRET"]
+    missing = [var for var in required_vars if not os.getenv(var)]
+    return pytest.mark.skipif(
+        bool(missing), reason=f"Missing environment variables: {', '.join(missing)}"
+    )
+
+
+def create_token(identity: str, room_name: str) -> str:
+    return (
+        api.AccessToken()
+        .with_identity(identity)
+        .with_name(identity)
+        .with_grants(
+            api.VideoGrants(
+                room_join=True,
+                room=room_name,
+            )
+        )
+        .to_jwt()
+    )
+
+
+def unique_room_name(base: str) -> str:
+    return f"{base}-{uuid.uuid4().hex[:8]}"
+
+
+async def _wait_until(
+    predicate: Callable[[], bool],
+    *,
+    timeout: float = WAIT_TIMEOUT,
+    interval: float = WAIT_INTERVAL,
+    message: str = "condition not met",
+) -> None:
+    loop = asyncio.get_event_loop()
+    deadline = loop.time() + timeout
+    while loop.time() < deadline:
+        if predicate():
+            return
+        await asyncio.sleep(interval)
+    raise AssertionError(f"timeout waiting: {message}")
+
+
+async def _connect(room: rtc.Room, identity: str, room_name: str) -> str:
+    token = create_token(identity, room_name)
+    url = os.environ["LIVEKIT_URL"]
+    await room.connect(url, token)
+    return token
+
+
+async def _ensure_all_connected(rooms: list[rtc.Room]) -> None:
+    await _wait_until(
+        lambda: all(r.connection_state == rtc.ConnectionState.CONN_CONNECTED for r in rooms),
+        message="not all rooms reached CONN_CONNECTED",
+    )
+
+
+async def _ensure_visible(observer: rtc.Room, identities: list[str]) -> None:
+    """Wait until `observer` sees every identity in `identities` as a remote participant.
+
+    Targeted publishes resolve identities at publish time, so we must let the
+    sender's room state catch up before sending."""
+
+    def _all_visible() -> bool:
+        seen = {p.identity for p in observer.remote_participants.values()}
+        return all(ident in seen for ident in identities)
+
+    await _wait_until(
+        _all_visible,
+        message=f"not all identities visible to {observer.local_participant.identity}: {identities}",
+    )
+
+
+def _expect_event(
+    room: rtc.Room,
+    event: EventTypes,
+    predicate: Optional[Callable[..., bool]] = None,
+) -> asyncio.Future:
+    loop = asyncio.get_event_loop()
+    fut: asyncio.Future = loop.create_future()
+
+    def _on_event(*args, **kwargs) -> None:
+        if fut.done():
+            return
+        if predicate is None or predicate(*args, **kwargs):
+            fut.set_result(args)
+
+    room.on(event, _on_event)
+    return fut
+
+
+async def _await_event(fut: asyncio.Future, timeout: float = WAIT_TIMEOUT) -> None:
+    try:
+        await asyncio.wait_for(fut, timeout=timeout)
+    except asyncio.TimeoutError as e:
+        raise AssertionError("timed out waiting for event") from e
+
+
+class _DataCollector:
+    """Collects `data_received` packets matching `sender_identity` (when set)."""
+
+    def __init__(self, room: rtc.Room, sender_identity: Optional[str] = None) -> None:
+        self.packets: list[rtc.DataPacket] = []
+        self._sender_identity = sender_identity
+
+        def _on_data(packet: rtc.DataPacket) -> None:
+            if self._sender_identity is not None and (
+                packet.participant is None or packet.participant.identity != self._sender_identity
+            ):
+                return
+            self.packets.append(packet)
+
+        room.on("data_received", _on_data)
+
+    def payloads(self) -> list[bytes]:
+        return [p.data for p in self.packets]
+
+    def topics(self) -> list[str | None]:
+        return [p.topic for p in self.packets]
+
+
+async def _assert_no_data(
+    room: rtc.Room, collector: _DataCollector, *, settle: float = 1.0
+) -> None:
+    """Give the server time to deliver, then assert nothing arrived."""
+    await asyncio.sleep(settle)
+    assert collector.packets == [], (
+        f"{room.local_participant.identity} unexpectedly received "
+        f"{len(collector.packets)} packet(s): {collector.payloads()}"
+    )
+
+
+@skip_if_no_credentials()
+@pytest.mark.asyncio
+async def test_data_one_to_one() -> None:
+    """sender targets a single identity; only that identity receives."""
+    room_name = unique_room_name("py-dc-1to1")
+
+    sender = rtc.Room()
+    receiver = rtc.Room()
+    bystander = rtc.Room()
+
+    await _connect(sender, "sender", room_name)
+    await _connect(receiver, "receiver", room_name)
+    await _connect(bystander, "bystander", room_name)
+    await _ensure_all_connected([sender, receiver, bystander])
+    await _ensure_visible(sender, ["receiver", "bystander"])
+
+    receiver_collector = _DataCollector(receiver, sender_identity="sender")
+    bystander_collector = _DataCollector(bystander, sender_identity="sender")
+
+    receiver_got = _expect_event(
+        receiver,
+        "data_received",
+        predicate=lambda packet: (
+            packet.participant is not None and packet.participant.identity == "sender"
+        ),
+    )
+
+    payload = b"hello receiver"
+    await sender.local_participant.publish_data(payload, destination_identities=["receiver"])
+
+    await _await_event(receiver_got)
+    assert receiver_collector.payloads() == [payload]
+    await _assert_no_data(bystander, bystander_collector)
+
+    await asyncio.gather(sender.disconnect(), receiver.disconnect(), bystander.disconnect())
+
+
+@skip_if_no_credentials()
+@pytest.mark.asyncio
+async def test_data_one_to_many_targeted() -> None:
+    """sender targets a subset of identities; only that subset receives."""
+    room_name = unique_room_name("py-dc-1tomany")
+
+    sender = rtc.Room()
+    r1 = rtc.Room()
+    r2 = rtc.Room()
+    excluded = rtc.Room()
+
+    await _connect(sender, "sender", room_name)
+    await _connect(r1, "r1", room_name)
+    await _connect(r2, "r2", room_name)
+    await _connect(excluded, "excluded", room_name)
+    await _ensure_all_connected([sender, r1, r2, excluded])
+    await _ensure_visible(sender, ["r1", "r2", "excluded"])
+
+    r1_collector = _DataCollector(r1, sender_identity="sender")
+    r2_collector = _DataCollector(r2, sender_identity="sender")
+    excluded_collector = _DataCollector(excluded, sender_identity="sender")
+
+    r1_got = _expect_event(
+        r1,
+        "data_received",
+        predicate=lambda packet: (
+            packet.participant is not None and packet.participant.identity == "sender"
+        ),
+    )
+    r2_got = _expect_event(
+        r2,
+        "data_received",
+        predicate=lambda packet: (
+            packet.participant is not None and packet.participant.identity == "sender"
+        ),
+    )
+
+    payload = b"hello selected"
+    await sender.local_participant.publish_data(payload, destination_identities=["r1", "r2"])
+
+    await asyncio.gather(_await_event(r1_got), _await_event(r2_got))
+    assert r1_collector.payloads() == [payload]
+    assert r2_collector.payloads() == [payload]
+    await _assert_no_data(excluded, excluded_collector)
+
+    await asyncio.gather(
+        sender.disconnect(), r1.disconnect(), r2.disconnect(), excluded.disconnect()
+    )
+
+
+@skip_if_no_credentials()
+@pytest.mark.asyncio
+async def test_data_broadcast() -> None:
+    """Empty `destination_identities` broadcasts to every other participant."""
+    room_name = unique_room_name("py-dc-broadcast")
+
+    sender = rtc.Room()
+    receivers = [rtc.Room() for _ in range(3)]
+    receiver_idents = [f"r{i}" for i in range(len(receivers))]
+
+    await _connect(sender, "sender", room_name)
+    for room, ident in zip(receivers, receiver_idents):
+        await _connect(room, ident, room_name)
+    await _ensure_all_connected([sender, *receivers])
+    await _ensure_visible(sender, receiver_idents)
+
+    collectors = [_DataCollector(room, sender_identity="sender") for room in receivers]
+    received_futures = [
+        _expect_event(
+            room,
+            "data_received",
+            predicate=lambda packet: (
+                packet.participant is not None and packet.participant.identity == "sender"
+            ),
+        )
+        for room in receivers
+    ]
+
+    payload = b"hello everyone"
+    await sender.local_participant.publish_data(payload)
+
+    await asyncio.gather(*(_await_event(f) for f in received_futures))
+    for ident, collector in zip(receiver_idents, collectors):
+        assert collector.payloads() == [payload], f"{ident} payloads mismatch"
+
+    await asyncio.gather(sender.disconnect(), *(r.disconnect() for r in receivers))
+
+
+@skip_if_no_credentials()
+@pytest.mark.asyncio
+async def test_data_topic_passthrough() -> None:
+    """Topic field is preserved end-to-end and observable by every receiver."""
+    room_name = unique_room_name("py-dc-topic")
+
+    sender = rtc.Room()
+    r1 = rtc.Room()
+    r2 = rtc.Room()
+
+    await _connect(sender, "sender", room_name)
+    await _connect(r1, "r1", room_name)
+    await _connect(r2, "r2", room_name)
+    await _ensure_all_connected([sender, r1, r2])
+    await _ensure_visible(sender, ["r1", "r2"])
+
+    r1_collector = _DataCollector(r1, sender_identity="sender")
+    r2_collector = _DataCollector(r2, sender_identity="sender")
+
+    # Send three messages: two on "chat", one on "telemetry".
+    messages = [
+        (b"chat-1", "chat"),
+        (b"telemetry-1", "telemetry"),
+        (b"chat-2", "chat"),
+    ]
+
+    def _all_received(collector: _DataCollector) -> bool:
+        return len(collector.packets) >= len(messages)
+
+    for payload, topic in messages:
+        await sender.local_participant.publish_data(payload, topic=topic)
+
+    await _wait_until(
+        lambda: _all_received(r1_collector) and _all_received(r2_collector),
+        message="receivers did not get all topic messages",
+    )
+
+    expected_pairs = [(payload, topic) for payload, topic in messages]
+    for collector, ident in [(r1_collector, "r1"), (r2_collector, "r2")]:
+        got = list(zip(collector.payloads(), collector.topics()))
+        assert got == expected_pairs, f"{ident} mismatch: expected {expected_pairs}, got {got}"
+
+    # Also verify `chat`-only filtering at the consumer side works as expected.
+    chat_only_r1 = [p for p in r1_collector.packets if p.topic == "chat"]
+    assert [p.data for p in chat_only_r1] == [b"chat-1", b"chat-2"]
+
+    await asyncio.gather(sender.disconnect(), r1.disconnect(), r2.disconnect())
+
+
+@skip_if_no_credentials()
+@pytest.mark.asyncio
+async def test_data_targeted_with_topic() -> None:
+    """Targeted send carries the topic; non-targets receive nothing."""
+    room_name = unique_room_name("py-dc-targeted-topic")
+
+    sender = rtc.Room()
+    target = rtc.Room()
+    other = rtc.Room()
+
+    await _connect(sender, "sender", room_name)
+    await _connect(target, "target", room_name)
+    await _connect(other, "other", room_name)
+    await _ensure_all_connected([sender, target, other])
+    await _ensure_visible(sender, ["target", "other"])
+
+    target_collector = _DataCollector(target, sender_identity="sender")
+    other_collector = _DataCollector(other, sender_identity="sender")
+
+    target_got = _expect_event(
+        target,
+        "data_received",
+        predicate=lambda packet: (
+            packet.participant is not None and packet.participant.identity == "sender"
+        ),
+    )
+
+    payload = b"private ping"
+    topic = "private"
+    await sender.local_participant.publish_data(
+        payload, destination_identities=["target"], topic=topic
+    )
+
+    await _await_event(target_got)
+    assert target_collector.payloads() == [payload]
+    assert target_collector.topics() == [topic]
+    await _assert_no_data(other, other_collector)
+
+    await asyncio.gather(sender.disconnect(), target.disconnect(), other.disconnect())