feat: Add setTimeout() method (#56)

Author: Rapsssito

README.md

@@ -2,7 +2,7 @@
 ![](https://github.com/Rapsssito/react-native-tcp-socket/workflows/tests/badge.svg)
 
 
-React Native TCP socket API for Android & iOS with **client SSL/TLS support**. It allows you to create TCP clients and servers sockets, imitating some of node's [net](https://nodejs.org/api/net.html) API functionalities (check the available [API](#api) for more information).
+React Native TCP socket API for Android & iOS with **client SSL/TLS support**. It allows you to create TCP clients and servers sockets, imitating some of Node's [net](https://nodejs.org/api/net.html) API functionalities (check the available [API](#api) for more information).
 
 ## Table of Contents
 
@@ -11,8 +11,8 @@ React Native TCP socket API for Android & iOS with **client SSL/TLS support**. I
 - [Compatibility](#react-native-compatibility)
 - [Usage](#usage)
 - [API](#api)
-  - [Client](#client)
-  - [Server](#server)
+  - [TcpSocket](#tcpsocket)
+  - [TcpServer](#tcpserver)
 - [Maintainers](#maintainers)
 - [Acknowledgments](#acknowledgments)
 - [License](#license)
@@ -113,7 +113,7 @@ To use this library you need to ensure you are using the correct version of Reac
 Import the library:
 ```javascript
 import TcpSocket from 'react-native-tcp-socket';
-// var net = require('react-native-tcp-socket');
+// const net = require('react-native-tcp-socket');
 ```
 ### Client
 ```javascript
@@ -179,12 +179,15 @@ const client = TcpSocket.createConnection({
 _Note: In order to use self-signed certificates make sure to [update your metro.config.js configuration](#self-signed-ssl-only-available-for-react-native--060)._
 
 ## API
-### Client
+Here are listed all methods implemented in `react-native-tcp-socket`, their functionalities are equivalent to those provided by Node's [net](https://nodejs.org/api/net.html) (more info on [#41](https://github.com/Rapsssito/react-native-tcp-socket/issues/41)). However, the **methods whose interface differs from Node are shown in bold**.
+
+### TcpSocket
 * **Methods:**
-  * [`createConnection(options[, callback])`](#createconnection)
-  * [`write(data[, encoding][, callback])`](#write)
-  * [`destroy()`](#destroy)
+  * **[`TcpSocket.createConnection(options[, callback])`](#createconnection)**
+  * [`write(data[, encoding][, callback])`](https://nodejs.org/api/net.html#net_socket_write_data_encoding_callback)
+  * [`destroy([error])`](https://nodejs.org/api/net.html#net_socket_destroy_error)
   * [`setNoDelay([noDelay])`](https://nodejs.org/api/net.html#net_socket_setnodelay_nodelay)
+  * [`setTimeout(timeout[, callback])`](https://nodejs.org/api/net.html#net_socket_settimeout_timeout_callback)
 
 #### `createConnection()`
 `createConnection(options[, callback])` creates a TCP connection using the given [`options`](#createconnection-options).
@@ -195,6 +198,7 @@ _Note: In order to use self-signed certificates make sure to [update your metro.
 | --------------------- | ------ | :--: | :-----: |-------------------------------------------------------------------------------------------------- |
 | **`port`** | `<number>` | ✅  |   ✅   | **Required**. Port the socket should connect to. |
 | `host` | `<string>` | ✅  |   ✅  | Host the socket should connect to. IP address in IPv4 format or `'localhost'`. **Default**: `'localhost'`. |
+| `timeout` | `<number>` | ✅  |   ✅  | If set, will be used to call [`setTimeout(timeout)`](https://nodejs.org/api/net.html#net_socket_settimeout_timeout_callback) after the socket is created, but before it starts the connection. |
 | `localAddress` | `<string>` | ✅  |   ✅  | Local address the socket should connect from. If not specified, the OS will decide. It is **highly recommended** to specify a `localAddress` to prevent overload errors and improve performance. |
 | `localPort` | `<number>` | ✅  |   ✅  | Local port the socket should connect from. If not specified, the OS will decide. |
 | `interface`| `<string>` | ❌  |   ✅  | Interface the socket should connect from. If not specified, it will use the current active connection. The options are: `'wifi', 'ethernet', 'cellular'`. |
@@ -205,18 +209,11 @@ _Note: In order to use self-signed certificates make sure to [update your metro.
 
 **Note**: The platforms marked as ❌ use the default value.
 
-#### `write()`
-* `data`: `<string> | <Buffer> | <Uint8Array>`
-* `encoding`: `<string>`. Only used when `data` is `string`. Default: `utf8`.
-* `callback `: `<Function>`
-
-`write(data[, encoding][, callback])` sends data on the socket. The second parameter specifies the encoding in the case of a string — it defaults to UTF8 encoding.
-
-### Server
+### TcpServer
 * **Methods:**
-  * [`createServer(callback)`](#createserver)
-  * [`listen(options[, callback])`](#listen)
-  * [`close()`](#close)
+  * [`TcpSocket.createServer(connectionListener)`](https://nodejs.org/api/net.html#net_net_createserver_options_connectionlistener)
+  * **[`listen(options[, callback])`](#listen)**
+  * [`close([callback])`](https://nodejs.org/api/net.html#net_server_close_callback)
 
 #### `listen()`
 `listen(options[, callback])` creates a TCP server socket using the given [`options`](#listen-options).

src/TcpSocket.js

@@ -15,7 +15,7 @@ const STATE = {
  * @typedef {{
  * port: number;
  * host?: string;
- * timeout?: number;
+ * timeout?: number,
  * localAddress?: string,
  * localPort?: number,
  * interface?: 'wifi' | 'cellular' | 'ethernet',
@@ -38,6 +38,9 @@ export default class TcpSocket extends EventEmitter {
         this._id = id;
         this._eventEmitter = eventEmitter;
         /** @type {number} */
+        this._timeoutMsecs = 0;
+        this._timeout = undefined;
+        /** @type {number} */
         this._state = STATE.DISCONNECTED;
         this._registerEvents();
         if (address != undefined) this._setConnected(address);
@@ -94,7 +97,7 @@ export default class TcpSocket extends EventEmitter {
         });
         // Timeout
         if (customOptions.timeout) this.setTimeout(customOptions.timeout);
-        else if (this._timeout) this._activeTimer(this._timeout.msecs);
+        else if (this._timeout) this._activateTimer();
         // TLS Cert
         if (customOptions.tlsCert) {
             customOptions.tlsCert = Image.resolveAssetSource(customOptions.tlsCert).uri;
@@ -107,53 +110,49 @@ export default class TcpSocket extends EventEmitter {
     }
 
     /**
-     * @private
-     * @param {number} msecs
-     * @param {() => void} [wrapper]
+     * Sets the socket to timeout after `timeout` milliseconds of inactivity on the socket. By default `TcpSocket` do not have a timeout.
+     *
+     * When an idle timeout is triggered the socket will receive a `'timeout'` event but the connection will not be severed.
+     * The user must manually call `socket.end()` or `socket.destroy()` to end the connection.
+     *
+     * If `timeout` is 0, then the existing idle timeout is disabled.
+     *
+     * The optional `callback` parameter will be added as a one-time listener for the `'timeout'` event.
+     *
+     * @param {number} timeout
+     * @param {() => void} [callback]
      */
-    _activeTimer(msecs, wrapper) {
-        if (this._timeout && this._timeout.handle) clearTimeout(this._timeout.handle);
-
-        if (!wrapper) {
-            const self = this;
-            wrapper = function() {
-                self._timeout = null;
-                self._eventEmitter.emit('timeout');
-            };
+    setTimeout(timeout, callback) {
+        if (timeout === 0) {
+            this._clearTimeout();
+        } else {
+            this._activateTimer(timeout);
         }
-
-        this._timeout = {
-            handle: setTimeout(wrapper, msecs),
-            wrapper: wrapper,
-            msecs: msecs,
-        };
+        if (callback) this.once('timeout', callback);
+        return this;
     }
 
     /**
      * @private
+     * @param {number} [timeout]
      */
-    _clearTimeout() {
-        if (this._timeout) {
-            clearTimeout(this._timeout.handle);
-            this._timeout = null;
-        }
+    _activateTimer(timeout) {
+        if (timeout !== undefined) this._timeoutMsecs = timeout;
+        this._clearTimeout();
+        this._timeout = setTimeout(() => {
+            this._clearTimeout();
+            this.emit('timeout');
+        }, this._timeoutMsecs);
     }
 
     /**
-     * @deprecated
-     * @param {number} msecs
-     * @param {(...args: any[]) => void } [callback]
+     * @private
      */
-    setTimeout(msecs, callback) {
-        if (msecs === 0) {
-            this._clearTimeout();
-            if (callback) this._eventEmitter.removeListener('timeout', callback);
-        } else {
-            if (callback) this._eventEmitter.once('timeout', callback, this);
-
-            this._activeTimer(msecs);
+    _clearTimeout() {
+        if (this._timeout !== undefined) {
+            clearTimeout(this._timeout);
+            this._timeout = undefined;
         }
-        return this;
     }
 
     /**
@@ -186,6 +185,7 @@ export default class TcpSocket extends EventEmitter {
             });
         } else {
             this._destroyed = true;
+            this._clearTimeout();
             Sockets.end(this._id);
         }
     }
@@ -242,7 +242,7 @@ export default class TcpSocket extends EventEmitter {
              * @param {string} err
              */
             function(err) {
-                if (self._timeout) self._activeTimer(self._timeout.msecs);
+                if (self._timeout) self._activateTimer();
                 if (callback) {
                     if (err) return callback(err);
                     callback(null);