feat(parsers): Add cctalk parsers (#1342)

* Added Working CCTalk Parser
* add basic tests
* compiled docs for cctalk parser

Author: frank-dspeed

README.md

@@ -788,6 +788,15 @@ const parser = port.pipe(new Regex({ regex: /[\r\n]+/ }));
 parser.on('data', console.log);
 ```
 
+To use the `CCTalk` parser you need to provide nothing. CCTalk Messages get emitted as buffer.
+```js
+const SerialPort = require('serialport');
+const CCTalk = SerialPort.parsers.CCTalk;
+const port = new SerialPort('/dev/ttyUSB0');
+const parser = port.pipe(new CCtalk());
+parser.on('data', console.log);
+```
+
 * * *
 
 <a name="module_serialport--SerialPort.list"></a>

lib/parsers/cctalk.js

@@ -0,0 +1,31 @@
+'use strict';
+const Transform = require('stream').Transform;
+const Buffer = require('safe-buffer').Buffer;
+
+module.exports = class CCTalkParser extends Transform {
+  constructor() {
+    super();
+    this.array = [];
+    this.cursor = 0;
+  }
+  _transform(buffer, _, cb) {
+    this.cursor += buffer.length;
+    // TODO: Better Faster es7 no supported by node 4
+    // ES7 allows directly push [...buffer]
+    // this.array = this.array.concat(Array.from(buffer)); //Slower ?!?
+    Array.from(buffer)
+      .map((byte) => this.array.push(byte));
+    while (this.cursor > 1 && this.cursor >= this.array[1] + 5) {
+      // full frame accumulated
+      // copy command from the array
+      const FullMsgLength = this.array[1] + 5;
+
+      const frame = Buffer.from(this.array.slice(0, FullMsgLength));
+      // Preserve Extra Data
+      this.array = this.array.slice(frame.length, this.array.length);
+      this.cursor -= FullMsgLength;
+      this.push(frame);
+    }
+    cb();
+  }
+};

lib/parsers/index.js

@@ -71,11 +71,21 @@ const Regex = SerialPort.parsers.Regex;
 const port = new SerialPort('/dev/tty-usbserial1');
 const parser = port.pipe(new Regex({ regex: /[\r\n]+/ }));
 parser.on('data', console.log);
+```
+
+To use the `CCTalk` parser you need to provide nothing. CCTalk Messages get emitted as buffer.
+```js
+const SerialPort = require('serialport');
+const CCTalk = SerialPort.parsers.CCTalk;
+const port = new SerialPort('/dev/ttyUSB0');
+const parser = port.pipe(new CCtalk());
+parser.on('data', console.log);
 ```
  */
 
 module.exports = {
   ByteLength: require('./byte-length'),
+  CCTalk: require('./cctalk'),
   Delimiter: require('./delimiter'),
   Readline: require('./readline'),
   Ready: require('./ready'),

test/parser-cctalk.js

@@ -0,0 +1,41 @@
+'use strict';
+/* eslint-disable no-new */
+
+const Buffer = require('safe-buffer').Buffer;
+const sinon = require('sinon');
+const CCTalkParser = require('../lib/parsers/cctalk');
+
+describe('CCTalkParser', () => {
+  it('emits data for a default length message', () => {
+    const data = Buffer.from([2, 0, 1, 254, 217]);
+    const spy = sinon.spy();
+    const parser = new CCTalkParser();
+    parser.on('data', spy);
+    parser.write(data);
+    assert.equal(spy.callCount, 1);
+    assert.deepEqual(spy.getCall(0).args[0], Buffer.from([2, 0, 1, 254, 217]));
+  });
+
+  it('emits data for a 7 byte length message', () => {
+    const parser = new CCTalkParser();
+    const spy = sinon.spy();
+    parser.on('data', spy);
+    parser.write(Buffer.from([2, 2, 1, 254, 1, 1, 217]));
+    assert.equal(spy.callCount, 1);
+    assert.deepEqual(spy.getCall(0).args[0], Buffer.from([2, 2, 1, 254, 1, 1, 217]));
+  });
+
+  it('emits 2 times data first length 7 secund length 5', () => {
+    const parser = new CCTalkParser();
+    const spy = sinon.spy();
+    parser.on('data', spy);
+    parser.write(Buffer.from([2, 2, 1]));
+    parser.write(Buffer.from([254, 1, 1]));
+    parser.write(Buffer.from([217, 2]));
+    parser.write(Buffer.from([0, 1, 254, 217]));
+    assert.equal(spy.callCount, 2);
+    assert.deepEqual(spy.getCall(0).args[0], Buffer.from([2, 2, 1, 254, 1, 1, 217]));
+    assert.deepEqual(spy.getCall(1).args[0], Buffer.from([2, 0, 1, 254, 217]));
+  });
+});
+// TODO: parser.write(Buffer.from([2, 2, 1, 254, 1, 1, 217, 2, 0, 1, 254, 217, 2, 2, 1, 251, 1, 1, 217, 2, 2, 1, 252, 1, 1, 217, 2, 0, 1, 253, 217]));