update network test and fix coroutines errors handling

dev/tests/network.lua

@@ -1,19 +1,38 @@
-local data = "hello, world"
-local complete = false
+for i=1,3 do
+    local text = ""
+    local complete = false
 
-network.tcp_open(7645, function (client)
-    start_coroutine(function()
-        local received = client:recv(1024)
-        if received then
-            assert (data, utf8.tostring(received))
+    for j=1,100 do
+        text = text .. math.random(0, 9)
+    end
+
+    local server = network.tcp_open(7645, function (client)
+        start_coroutine(function()
+            local received_text = ""
+            while client:is_alive() do
+                local received = client:recv(512)
+                if received then
+                    received_text = received_text .. utf8.tostring(received)
+                end
+                coroutine.yield()
+            end
+            assert (received_text == text)
             complete = true
-        end
-        coroutine.yield()
-    end, "client-listener")
-end)
+        end, "client-listener")
+    end)
 
-network.tcp_connect("localhost", 7645, function (socket)
-    socket:send(data)
-end)
+    network.tcp_connect("localhost", 7645, function (socket)
+        start_coroutine(function()
+            local ptr = 1
+            while ptr < #text do
+                local n = math.random(1, 20)
+                socket:send(string.sub(text, ptr, ptr + n - 1))
+                ptr = ptr + n
+            end
+            socket:close()
+        end, "data-sender")
+    end)
 
-app.sleep_until(function () return complete end)
+    app.sleep_until(function () return complete end)
+    server:close()
+end