docs: Added polling_echo example.

zmq_test.odin

@@ -5,9 +5,80 @@ package zmq
 import "core:testing"
 
 @(test)
-test_error_type :: proc(t: ^testing.T) {
-	e: Error = .EFSM
+test_version :: proc(t: ^testing.T) {
+	ma, mi, pa := version()
 
-	testing.expect_value(t, size_of(e), 8)
+	testing.expect_value(t, ma, 4)
+	testing.expect_value(t, mi, 3)
+	testing.expect_value(t, pa, 5)
+}
+
+@(test)
+test_simple_const_echo :: proc(t: ^testing.T) {
+	ctx := ctx_new()
+	defer ctx_term(ctx)
+
+	srv, serr := socket(ctx, .REP)
+	testing.expect_value(t, serr, nil)
+	if serr != nil {
+		testing.fail_now(t, "Can't create server socket")
+	}
+	defer close(srv)
+
+	if err := bind(srv, "inproc://echo"); err != nil {
+		testing.expect_value(t, err, nil)
+		testing.fail_now(t, "Can't bind server socket")
+	}
+
+	cli, cerr := socket(ctx, .REQ)
+	testing.expect_value(t, cerr, nil)
+	if cerr != nil {
+		testing.fail_now(t, "Can't create client socket")
+	}
+	defer close(cli)
+	err := connect(cli, "inproc://echo")
+	testing.expect_value(t, err, nil)
+	if err != nil {
+		testing.fail_now(t, "Can't connect client to server")
+	}
+
+	msg :: "Hello, World"
+	buf: [len(msg)]u8
+
+	_, err = send_const(cli, msg)
+	testing.expect_value(t, err, nil)
+	if err != nil {
+		testing.fail_now(t, "Can't send message")
+	}
+
+	{
+		n := 0
+		n, err = recv(srv, buf[:])
+		testing.expect_value(t, n, len(msg))
+		testing.expect_value(t, err, nil)
+		if err != nil || n != len(msg) {
+			testing.fail_now(t, "Can't receive message")
+		}
+
+		testing.expect_value(t, string(buf[:n]), string(msg))
+
+		_, err := send(srv, buf[:n])
+		testing.expect_value(t, err, nil)
+		if err != nil {
+			testing.fail_now(t, "Can't send message")
+		}
+	}
+
+	{
+		m := 0
+		m, err = recv(cli, buf[:])
+		testing.expect_value(t, m, len(msg))
+		testing.expect_value(t, err, nil)
+		if err != nil || m != len(msg) {
+			testing.fail_now(t, "Can't receive message")
+		}
+
+		testing.expect_value(t, string(buf[:m]), string(msg))
+	}
 }