Fix examples

tests/examples/test_examples.py

@@ -0,0 +1,101 @@
+import pytest
+import trio
+
+from libp2p.host.exceptions import StreamFailure
+from libp2p.peer.peerinfo import info_from_p2p_addr
+from libp2p.tools.factories import HostFactory
+from libp2p.tools.utils import MAX_READ_LEN
+
+PROTOCOL_ID = "/chat/1.0.0"
+
+
+async def hello_world(host_a, host_b):
+    hello_world_from_host_a = b"hello world from host a"
+    hello_world_from_host_b = b"hello world from host b"
+
+    async def stream_handler(stream):
+        read = await stream.read(len(hello_world_from_host_b))
+        assert read == hello_world_from_host_b
+        await stream.write(hello_world_from_host_a)
+        await stream.close()
+
+    host_a.set_stream_handler(PROTOCOL_ID, stream_handler)
+
+    # Start a stream with the destination.
+    # Multiaddress of the destination peer is fetched from the peerstore using 'peerId'.
+    stream = await host_b.new_stream(host_a.get_id(), [PROTOCOL_ID])
+    await stream.write(hello_world_from_host_b)
+    read = await stream.read(MAX_READ_LEN)
+    assert read == hello_world_from_host_a
+    await stream.close()
+
+
+async def connect_write(host_a, host_b):
+    messages = ["data %d" % i for i in range(5)]
+    received = []
+
+    async def stream_handler(stream):
+        for message in messages:
+            received.append((await stream.read(len(message))).decode())
+
+    host_a.set_stream_handler(PROTOCOL_ID, stream_handler)
+
+    # Start a stream with the destination.
+    # Multiaddress of the destination peer is fetched from the peerstore using 'peerId'.
+    stream = await host_b.new_stream(host_a.get_id(), [PROTOCOL_ID])
+    for message in messages:
+        await stream.write(message.encode())
+
+    # Reader needs time due to async reads
+    await trio.sleep(2)
+
+    await stream.close()
+    assert received == messages
+
+
+async def connect_read(host_a, host_b):
+    messages = [b"data %d" % i for i in range(5)]
+
+    async def stream_handler(stream):
+        for message in messages:
+            await stream.write(message)
+        await stream.close()
+
+    host_a.set_stream_handler(PROTOCOL_ID, stream_handler)
+
+    # Start a stream with the destination.
+    # Multiaddress of the destination peer is fetched from the peerstore using 'peerId'.
+    stream = await host_b.new_stream(host_a.get_id(), [PROTOCOL_ID])
+    received = []
+    for message in messages:
+        received.append(await stream.read(len(message)))
+    await stream.close()
+    assert received == messages
+
+
+async def no_common_protocol(host_a, host_b):
+    messages = [b"data %d" % i for i in range(5)]
+
+    async def stream_handler(stream):
+        for message in messages:
+            await stream.write(message)
+        await stream.close()
+
+    host_a.set_stream_handler(PROTOCOL_ID, stream_handler)
+
+    # try to creates a new new with a procotol not known by the other host
+    with pytest.raises(StreamFailure):
+        await host_b.new_stream(host_a.get_id(), ["/fakeproto/0.0.1"])
+
+
+@pytest.mark.parametrize(
+    "test", [(hello_world), (connect_write), (connect_read), (no_common_protocol)]
+)
+@pytest.mark.trio
+async def test_chat(test, is_host_secure):
+    async with HostFactory.create_batch_and_listen(is_host_secure, 2) as hosts:
+        addr = hosts[0].get_addrs()[0]
+        info = info_from_p2p_addr(addr)
+        await hosts[1].connect(info)
+
+        await test(hosts[0], hosts[1])