diff --git a/tests/0-tcp.d b/tests/0-tcp.d
new file mode 100644
index 0000000..453f6e6
--- /dev/null
+++ b/tests/0-tcp.d
@@ -0,0 +1,190 @@
+/+ dub.sdl:
+	name "tests"
+	description "TCP semantics tests"
+	copyright "Copyright © 2015-2020, Sönke Ludwig"
+	dependency "vibe-core" path=".."
++/
+module tests;
+
+import vibe.core.core;
+import vibe.core.log;
+import vibe.core.net;
+import core.time;
+import std.datetime.stopwatch : StopWatch;
+
+enum Test {
+  receive,
+  receiveExisting,
+  timeout,
+  noTimeout,
+  close
+}
+
+void test1()
+{
+	Test test;
+	Task lt;
+
+	auto l = listenTCP(0, (conn) {
+		lt = Task.getThis();
+		try {
+			while (!conn.empty) {
+				assert(conn.readLine() == "next");
+				auto curtest = test;
+				conn.write("continue\n");
+				logInfo("Perform test %s", curtest);
+				StopWatch sw;
+				sw.start();
+				final switch (curtest) {
+					case Test.receive:
+						assert(conn.waitForData(2.seconds) == true);
+						assert(cast(Duration)sw.peek < 2.seconds); // should receive something instantly
+						assert(conn.readLine() == "receive");
+						break;
+					case Test.receiveExisting:
+						assert(conn.waitForData(2.seconds) == true);
+						// TODO: validate that waitForData didn't yield!
+						assert(cast(Duration)sw.peek < 2.seconds); // should receive something instantly
+						assert(conn.readLine() == "receiveExisting");
+						break;
+					case Test.timeout:
+						assert(conn.waitForData(2.seconds) == false);
+						assert(cast(Duration)sw.peek > 1900.msecs); // should wait for at least 2 seconds
+						assert(conn.connected);
+						break;
+					case Test.noTimeout:
+						assert(conn.waitForData(Duration.max) == true);
+						assert(cast(Duration)sw.peek > 2.seconds); // data only sent after 3 seconds
+						assert(conn.readLine() == "noTimeout");
+						break;
+					case Test.close:
+						assert(conn.waitForData(2.seconds) == false);
+						assert(cast(Duration)sw.peek < 2.seconds); // connection should be closed instantly
+						assert(conn.empty);
+						conn.close();
+						assert(!conn.connected);
+						return;
+				}
+				conn.write("ok\n");
+			}
+		} catch (Exception e) {
+			assert(false, e.msg);
+		}
+	}, "127.0.0.1");
+	scope (exit) l.stopListening;
+
+	auto conn = connectTCP(l.bindAddress);
+
+	test = Test.receive;
+	conn.write("next\n");
+	assert(conn.readLine() == "continue");
+	conn.write("receive\n");
+	assert(conn.readLine() == "ok");
+
+	test = Test.receiveExisting;
+	conn.write("next\nreceiveExisting\n");
+	assert(conn.readLine() == "continue");
+	assert(conn.readLine() == "ok");
+
+	test = Test.timeout;
+	conn.write("next\n");
+	assert(conn.readLine() == "continue");
+	sleep(3.seconds);
+	assert(conn.readLine() == "ok");
+
+	test = Test.noTimeout;
+	conn.write("next\n");
+	assert(conn.readLine() == "continue");
+	sleep(3.seconds);
+	conn.write("noTimeout\n");
+	assert(conn.readLine() == "ok");
+
+	test = Test.close;
+	conn.write("next\n");
+	assert(conn.readLine() == "continue");
+	conn.close();
+
+	lt.join();
+}
+
+void test2()
+{
+	Task lt;
+	logInfo("Perform test \"disconnect with pending data\"");
+	auto l = listenTCP(0, (conn) {
+		try {
+			lt = Task.getThis();
+			sleep(1.seconds);
+			StopWatch sw;
+			sw.start();
+			try {
+				assert(conn.waitForData() == true);
+				assert(cast(Duration)sw.peek < 500.msecs); // waitForData should return immediately
+				assert(conn.dataAvailableForRead);
+				assert(conn.readAll() == "test");
+				conn.close();
+			} catch (Exception e) {
+				assert(false, "Failed to read pending data: " ~ e.msg);
+			}
+		} catch (Exception e) {
+			assert(false, e.msg);
+		}
+	}, "127.0.0.1");
+	scope (exit) l.stopListening;
+
+	auto conn = connectTCP(l.bindAddress);
+	conn.write("test");
+	conn.close();
+
+	sleep(100.msecs);
+
+	assert(lt != Task.init);
+	lt.join();
+}
+
+void test()
+{
+	test1();
+	test2();
+	exitEventLoop();
+}
+
+void main()
+{
+	import std.functional : toDelegate;
+	runTask(toDelegate(&test));
+	runEventLoop();
+}
+
+string readLine(TCPConnection c)
+{
+	import std.string : indexOf;
+
+	string ret;
+	while (!c.empty) {
+		auto buf = cast(char[])c.peek();
+		auto idx = buf.indexOf('\n');
+		if (idx < 0) {
+			ret ~= buf;
+			c.skip(buf.length);
+		} else {
+			ret ~= buf[0 .. idx];
+			c.skip(idx+1);
+			break;
+		}
+	}
+	return ret;
+}
+
+string readAll(TCPConnection c)
+{
+	import std.algorithm.comparison : min;
+
+	ubyte[] ret;
+	while (!c.empty) {
+		auto len = min(c.leastSize, size_t.max);
+		ret.length += len;
+		c.read(ret[$-len .. $]);
+	}
+	return cast(string)ret;
+}
diff --git a/tests/0-tcpproxy.d b/tests/0-tcpproxy.d
new file mode 100644
index 0000000..38be778
--- /dev/null
+++ b/tests/0-tcpproxy.d
@@ -0,0 +1,134 @@
+/+ dub.sdl:
+	name "tests"
+	description "TCP proxy test"
+	copyright "Copyright © 2015-2020, Sönke Ludwig"
+	dependency "vibe-core" path=".."
++/
+module tests;
+
+import vibe.core.core;
+import vibe.core.log;
+import vibe.core.net;
+import vibe.core.stream;
+import std.exception;
+import std.string;
+import std.range.primitives : front;
+import core.time;
+
+
+void testProtocol(TCPConnection server, bool terminate)
+{
+	foreach (i; 0 .. 1) {
+		foreach (j; 0 .. 1) {
+			auto str = format("Hello, World #%s", i*100+j);
+			server.write(str);
+			server.write("\n");
+			auto reply = server.readLine();
+			assert(reply == format("Hash: %08X", typeid(string).getHash(&str)), "Unexpected reply");
+		}
+		sleep(10.msecs);
+	}
+
+	assert(!server.dataAvailableForRead, "Still data available.");
+
+	if (terminate) {
+		// forcefully close connection
+		server.close();
+	} else {
+		server.write("quit\n");
+		enforce(server.readLine() == "Bye bye!");
+		// should have closed within 500 ms
+		enforce(!server.waitForData(500.msecs));
+		assert(server.empty, "Server still connected.");
+	}
+}
+
+void runTest()
+{
+	import std.algorithm : find;
+	import std.socket : AddressFamily;
+
+	// server for a simple line based protocol
+	auto l1 = listenTCP(0, (client) {
+		while (!client.empty) {
+			auto ln = client.readLine();
+			if (ln == "quit") {
+				client.write("Bye bye!\n");
+				client.close();
+				break;
+			}
+
+			client.write(format("Hash: %08X\n", typeid(string).getHash(&ln)));
+		}
+	}, "127.0.0.1");
+	scope (exit) l1.stopListening;
+
+	// proxy server
+	auto l2 = listenTCP(0, (client) {
+		auto server = connectTCP(l1.bindAddress);
+
+		// pipe server to client as long as the server connection is alive
+		auto t = runTask!(TCPConnection, TCPConnection)((client, server) {
+			scope (exit) client.close();
+			pipe(server, client);
+			logInfo("Proxy 2 out");
+		}, client, server);
+
+		// pipe client to server as long as the client connection is alive
+		scope (exit) {
+			server.close();
+			t.join();
+		}
+		pipe(client, server);
+		logInfo("Proxy out");
+	}, "127.0.0.1");
+	scope (exit) l2.stopListening;
+
+	// test server
+	logInfo("Test protocol implementation on server");
+	testProtocol(connectTCP(l2.bindAddress), false);
+	logInfo("Test protocol implementation on server with forced disconnect");
+	testProtocol(connectTCP(l2.bindAddress), true);
+
+	// test proxy
+	logInfo("Test protocol implementation on proxy");
+	testProtocol(connectTCP(l2.bindAddress), false);
+	logInfo("Test protocol implementation on proxy with forced disconnect");
+	testProtocol(connectTCP(l2.bindAddress), true);
+}
+
+int main()
+{
+	int ret = 0;
+	runTask({
+		try runTest();
+		catch (Throwable th) {
+			logError("Test failed: %s", th.msg);
+			logDiagnostic("Full error: %s", th);
+			ret = 1;
+		} finally exitEventLoop(true);
+	});
+	runEventLoop();
+	return ret;
+}
+
+string readLine(TCPConnection c)
+{
+	import std.string : indexOf;
+
+	string ret;
+	while (!c.empty) {
+		auto buf = cast(char[])c.peek();
+		auto idx = buf.indexOf('\n');
+		if (idx < 0) {
+			ret ~= buf;
+			c.skip(buf.length);
+		} else {
+			ret ~= buf[0 .. idx];
+			c.skip(idx+1);
+			break;
+		}
+	}
+	return ret;
+}
+