[all] Change parsers to be es6 classes

- Reduces code a bit - Provides a better code example - clean up options passing into transform streams
serialport · Jul 29, 2017 · 8b07a48 · 8b07a48
1 parent ae89830
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diff --git a/README.md b/README.md
@@ -723,54 +723,64 @@ The default `Parsers` are [Transform streams](https://nodejs.org/api/stream.html
 
 **Example**  
 ```js
-var SerialPort = require('serialport');
-var Readline = SerialPort.parsers.Readline;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = new Readline();
+const SerialPort = require('serialport');
+const Readline = SerialPort.parsers.Readline;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = new Readline();
 port.pipe(parser);
 parser.on('data', console.log);
 port.write('ROBOT PLEASE RESPOND\n');
 
 // Creating the parser and piping can be shortened to
-var parser = port.pipe(new Readline());
+// const parser = port.pipe(new Readline());
 ```
 
 To use the `ByteLength` parser, provide the length of the number of bytes:
 ```js
-var SerialPort = require('serialport');
-var ByteLength = SerialPort.parsers.ByteLength
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(new ByteLength({length: 8}));
+const SerialPort = require('serialport');
+const ByteLength = SerialPort.parsers.ByteLength
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(new ByteLength({length: 8}));
 parser.on('data', console.log);
 ```
 
 To use the `Delimiter` parser, provide a delimiter as a string, buffer, or array of bytes:
 ```js
-var SerialPort = require('serialport');
-var Delimiter = SerialPort.parsers.Delimiter;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(new Delimiter({delimiter: Buffer.from('EOL')}));
+const SerialPort = require('serialport');
+const Delimiter = SerialPort.parsers.Delimiter;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(new Delimiter({ delimiter: Buffer.from('EOL') }));
 parser.on('data', console.log);
 ```
 
-To use the `Readline` parser, provide a delimiter (defaults to '\n')
+To use the `Readline` parser, provide a delimiter (defaults to '\n'). Data is emitted as string controllable by the `encoding` option (defaults to `utf8`).
 ```js
-var SerialPort = require('serialport');
-var Readline = SerialPort.parsers.Readline;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(Readline({delimiter: '\r\n'}));
+const SerialPort = require('serialport');
+const Readline = SerialPort.parsers.Readline;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(Readline({ delimiter: '\r\n' }));
 parser.on('data', console.log);
 ```
 
-To use the `Ready` parser provide a byte start sequence. After the bytes have been received data events will be passed through.
+To use the `Ready` parser provide a byte start sequence. After the bytes have been received data events are passed through.
 ```js
-var SerialPort = require('serialport');
-var Ready = SerialPort.parsers.Ready;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(Ready({data: 'READY'}));
+const SerialPort = require('serialport');
+const Ready = SerialPort.parsers.Ready;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(Ready({ data: 'READY' }));
+parser.on('ready', () => console.log('the ready byte sequence has been received'))
 parser.on('data', console.log); // all data after READY is received
 ```
 
+To use the `Regex` parser provide a regular expression to split the incoming text upon. Data is emitted as string controllable by the `encoding` option (defaults to `utf8`).
+```js
+const SerialPort = require('serialport');
+const Regex = SerialPort.parsers.Regex;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(Regex({ regex: /[\r\n]+/ }));
+parser.on('data', console.log);
+```
+
 * * *
 
 <a name="module_serialport--SerialPort.list"></a>

diff --git a/lib/parsers/byte-length.js b/lib/parsers/byte-length.js
@@ -1,45 +1,38 @@
 'use strict';
 const Buffer = require('safe-buffer').Buffer;
-const inherits = require('util').inherits;
 const Transform = require('stream').Transform;
 
-function ByteLengthParser(options) {
-  if (!(this instanceof ByteLengthParser)) {
-    return new ByteLengthParser(options);
-  }
-  Transform.call(this, options);
+module.exports = class ByteLengthParser extends Transform {
+  constructor(options) {
+    super(options);
+    options = options || {};
 
-  options = options || {};
+    if (typeof options.length !== 'number') {
+      throw new TypeError('"length" is not a number');
+    }
 
-  if (typeof options.length !== 'number') {
-    throw new TypeError('"length" is not a number');
-  }
+    if (options.length < 1) {
+      throw new TypeError('"length" is not greater than 0');
+    }
 
-  if (options.length < 1) {
-    throw new TypeError('"length" is not greater than 0');
+    this.length = options.length;
+    this.buffer = Buffer.alloc(0);
   }
 
-  this.length = options.length;
-  this.buffer = Buffer.alloc(0);
-}
-
-inherits(ByteLengthParser, Transform);
-
-ByteLengthParser.prototype._transform = function(chunk, encoding, cb) {
-  let data = Buffer.concat([this.buffer, chunk]);
-  while (data.length >= this.length) {
-    const out = data.slice(0, this.length);
-    this.push(out);
-    data = data.slice(this.length);
+  _transform(chunk, encoding, cb) {
+    let data = Buffer.concat([this.buffer, chunk]);
+    while (data.length >= this.length) {
+      const out = data.slice(0, this.length);
+      this.push(out);
+      data = data.slice(this.length);
+    }
+    this.buffer = data;
+    cb();
   }
-  this.buffer = data;
-  cb();
-};
 
-ByteLengthParser.prototype._flush = function(cb) {
-  this.push(this.buffer);
-  this.buffer = Buffer.alloc(0);
-  cb();
+  _flush(cb) {
+    this.push(this.buffer);
+    this.buffer = Buffer.alloc(0);
+    cb();
+  }
 };
-
-module.exports = ByteLengthParser;
diff --git a/lib/parsers/delimiter.js b/lib/parsers/delimiter.js
@@ -1,45 +1,38 @@
 'use strict';
 const Buffer = require('safe-buffer').Buffer;
-const inherits = require('util').inherits;
 const Transform = require('stream').Transform;
 
-function DelimiterParser(options) {
-  if (!(this instanceof DelimiterParser)) {
-    return new DelimiterParser(options);
-  }
-  Transform.call(this, options);
+module.exports = class DelimiterParser extends Transform {
+  constructor(options) {
+    options = options || {};
+    super(options);
 
-  options = options || {};
+    if (options.delimiter === undefined) {
+      throw new TypeError('"delimiter" is not a bufferable object');
+    }
 
-  if (options.delimiter === undefined) {
-    throw new TypeError('"delimiter" is not a bufferable object');
-  }
+    if (options.delimiter.length === 0) {
+      throw new TypeError('"delimiter" has a 0 or undefined length');
+    }
 
-  if (options.delimiter.length === 0) {
-    throw new TypeError('"delimiter" has a 0 or undefined length');
+    this.delimiter = Buffer.from(options.delimiter);
+    this.buffer = Buffer.alloc(0);
   }
 
-  this.delimiter = Buffer.from(options.delimiter);
-  this.buffer = Buffer.alloc(0);
-}
-
-inherits(DelimiterParser, Transform);
-
-DelimiterParser.prototype._transform = function(chunk, encoding, cb) {
-  let data = Buffer.concat([this.buffer, chunk]);
-  let position;
-  while ((position = data.indexOf(this.delimiter)) !== -1) {
-    this.push(data.slice(0, position));
-    data = data.slice(position + this.delimiter.length);
+  _transform(chunk, encoding, cb) {
+    let data = Buffer.concat([this.buffer, chunk]);
+    let position;
+    while ((position = data.indexOf(this.delimiter)) !== -1) {
+      this.push(data.slice(0, position));
+      data = data.slice(position + this.delimiter.length);
+    }
+    this.buffer = data;
+    cb();
   }
-  this.buffer = data;
-  cb();
-};
 
-DelimiterParser.prototype._flush = function(cb) {
-  this.push(this.buffer);
-  this.buffer = Buffer.alloc(0);
-  cb();
+  _flush(cb) {
+    this.push(this.buffer);
+    this.buffer = Buffer.alloc(0);
+    cb();
+  }
 };
-
-module.exports = DelimiterParser;
diff --git a/lib/parsers/index.js b/lib/parsers/index.js
@@ -12,59 +12,69 @@
  * @since 5.0.0
  * @example
 ```js
-var SerialPort = require('serialport');
-var Readline = SerialPort.parsers.Readline;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = new Readline();
+const SerialPort = require('serialport');
+const Readline = SerialPort.parsers.Readline;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = new Readline();
 port.pipe(parser);
 parser.on('data', console.log);
 port.write('ROBOT PLEASE RESPOND\n');
 
 // Creating the parser and piping can be shortened to
-var parser = port.pipe(new Readline());
+// const parser = port.pipe(new Readline());
 ```
 
 To use the `ByteLength` parser, provide the length of the number of bytes:
 ```js
-var SerialPort = require('serialport');
-var ByteLength = SerialPort.parsers.ByteLength
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(new ByteLength({length: 8}));
+const SerialPort = require('serialport');
+const ByteLength = SerialPort.parsers.ByteLength
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(new ByteLength({length: 8}));
 parser.on('data', console.log);
 ```
 
 To use the `Delimiter` parser, provide a delimiter as a string, buffer, or array of bytes:
 ```js
-var SerialPort = require('serialport');
-var Delimiter = SerialPort.parsers.Delimiter;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(new Delimiter({delimiter: Buffer.from('EOL')}));
+const SerialPort = require('serialport');
+const Delimiter = SerialPort.parsers.Delimiter;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(new Delimiter({ delimiter: Buffer.from('EOL') }));
 parser.on('data', console.log);
 ```
 
-To use the `Readline` parser, provide a delimiter (defaults to '\n')
+To use the `Readline` parser, provide a delimiter (defaults to '\n'). Data is emitted as string controllable by the `encoding` option (defaults to `utf8`).
 ```js
-var SerialPort = require('serialport');
-var Readline = SerialPort.parsers.Readline;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(Readline({delimiter: '\r\n'}));
+const SerialPort = require('serialport');
+const Readline = SerialPort.parsers.Readline;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(Readline({ delimiter: '\r\n' }));
 parser.on('data', console.log);
 ```
 
-To use the `Ready` parser provide a byte start sequence. After the bytes have been received data events will be passed through.
+To use the `Ready` parser provide a byte start sequence. After the bytes have been received data events are passed through.
 ```js
-var SerialPort = require('serialport');
-var Ready = SerialPort.parsers.Ready;
-var port = new SerialPort('/dev/tty-usbserial1');
-var parser = port.pipe(Ready({data: 'READY'}));
+const SerialPort = require('serialport');
+const Ready = SerialPort.parsers.Ready;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(Ready({ data: 'READY' }));
+parser.on('ready', () => console.log('the ready byte sequence has been received'))
 parser.on('data', console.log); // all data after READY is received
+```
+
+To use the `Regex` parser provide a regular expression to split the incoming text upon. Data is emitted as string controllable by the `encoding` option (defaults to `utf8`).
+```js
+const SerialPort = require('serialport');
+const Regex = SerialPort.parsers.Regex;
+const port = new SerialPort('/dev/tty-usbserial1');
+const parser = port.pipe(Regex({ regex: /[\r\n]+/ }));
+parser.on('data', console.log);
 ```
  */
 
 module.exports = {
-  Readline: require('./readline'),
-  Delimiter: require('./delimiter'),
   ByteLength: require('./byte-length'),
-  Regex: require('./regex'),
-  Ready: require('./ready')
+  Delimiter: require('./delimiter'),
+  Readline: require('./readline'),
+  Ready: require('./ready'),
+  Regex: require('./regex')
 };
diff --git a/lib/parsers/readline.js b/lib/parsers/readline.js
@@ -1,26 +1,18 @@
 'use strict';
-
-const inherits = require('util').inherits;
 const Buffer = require('safe-buffer').Buffer;
 const DelimiterParser = require('./delimiter');
 
-function ReadlineParser(options) {
-  if (!(this instanceof ReadlineParser)) {
-    return new ReadlineParser(options);
-  }
+module.exports = class ReadLineParser extends DelimiterParser {
+  constructor(options) {
+    const opts = Object.assign({
+      delimiter: Buffer.from('\n', 'utf8'),
+      encoding: 'utf8'
+    }, options);
 
-  options = options || {};
+    if (typeof opts.delimiter === 'string') {
+      opts.delimiter = Buffer.from(opts.delimiter, opts.encoding);
+    }
 
-  if (options.delimiter === undefined) {
-    options.delimiter = Buffer.from('\n', 'utf8');
+    super(opts);
   }
-
-  DelimiterParser.call(this, options);
-
-  const encoding = options.encoding || 'utf8';
-  this.delimiter = Buffer.from(options.delimiter, encoding);
-  this.setEncoding(encoding);
-}
-
-inherits(ReadlineParser, DelimiterParser);
-module.exports = ReadlineParser;
+};