feat: add JS variant of LoraMessage

example/.eslintrc

@@ -0,0 +1,17 @@
+{
+  "extends": "../.eslintrc.js",
+  "rules": {
+    "no-unused-vars": 0
+  },
+  "globals": {
+    "encode": false,
+    "decode": false,
+    "LoraMessage": false,
+    "unixtime": false,
+    "latLng": false,
+    "uint16": false,
+    "uint8": false,
+    "temperature": false,
+    "humidity": false,
+  }
+}

example/main_encoder_LoraMessage.ino

@@ -0,0 +1,13 @@
+#include <LoraMessage.h>
+
+void setup() {
+    LoraMessage message;
+    message.addUnixtime(1468075322);
+    message.addLatLng(-33.905024, 151.26648);
+
+    do_send(message.getLength(), message.getBytes());
+}
+
+void loop(void) {
+    os_runloop_once();
+}

example/ttn_decoder.js

@@ -1,4 +1,4 @@
-function(bytes) {
+function ttn_decoder(bytes) {
   // bytes is of type Buffer
 
   // IMPORTANT: paste code from src/decoder.js here

example/ttn_encoder.js

@@ -0,0 +1,8 @@
+function ttn_encoder() {
+  // IMPORTANT: paste code from src/encoder.js here
+
+  return encode(
+    [ Date.now() / 1000,    [-33.905052, 151.26641]   ],
+    [ unixtime,             latLng                    ]
+  );
+}

example/ttn_encoder_LoraMessage.js

@@ -0,0 +1,8 @@
+function ttn_encoder() {
+  // IMPORTANT: paste code from src/encoder.js here
+  // IMPORTANT: paste code from src/LoraMessage.js here
+
+  return new LoraMessage()
+    .addUnixtime(Date.now() / 1000)
+    .addLatLng(-33.905052, 151.26641);
+}

package.json

@@ -12,6 +12,7 @@
   },
   "scripts": {
     "lint": "eslint .",
+    "tdd": "mocha --watch",
     "test": "mocha"
   },
   "keywords": [

src/LoraMessage.js

@@ -0,0 +1,65 @@
+(function(root) {
+  function LoraMessage(encoder) {
+    this.dataTuples = [];
+    this.encoder = encoder || root;
+  }
+
+  LoraMessage.prototype.addTuple = function(data, fnName) {
+    this.dataTuples.push({
+      data: data,
+      fn: this.encoder[fnName]
+    });
+  };
+
+
+  LoraMessage.prototype.addUnixtime = function(unixtime) {
+    this.addTuple([unixtime], 'unixtime');
+    return this;
+  };
+
+  LoraMessage.prototype.addLatLng = function(latitude, longitude) {
+    this.addTuple([latitude, longitude], 'latLng');
+    return this;
+  };
+
+  LoraMessage.prototype.addUint16 = function(uint16) {
+    this.addTuple([uint16], 'uint16');
+    return this;
+  };
+
+  LoraMessage.prototype.addTemperature = function(temperature) {
+    this.addTuple([temperature], 'temperature');
+    return this;
+  };
+
+  LoraMessage.prototype.addUint8 = function(uint8) {
+    this.addTuple([uint8], 'uint8');
+    return this;
+  };
+
+  LoraMessage.prototype.addHumidity = function(humidity) {
+    this.addTuple([humidity], 'humidity');
+    return this;
+  };
+
+  LoraMessage.prototype.getBytes = function() {
+    var buffer = new Buffer(this.getLength());
+    var offset = 0;
+    this.dataTuples.forEach(function(tuple) {
+      var current = tuple.fn.apply(null, tuple.data);
+      current.copy(buffer, offset);
+      offset += tuple.fn.BYTES;
+    });
+    return buffer;
+  };
+
+  LoraMessage.prototype.getLength = function() {
+    return this.dataTuples.reduce(function(previous, tuple) {
+      return previous + tuple.fn.BYTES;
+    }, 0);
+  };
+
+  if (typeof module === 'object' && typeof module.exports !== 'undefined') {
+    module.exports = LoraMessage;
+  }
+})(this);

test/spec.LoraMessage.js

@@ -0,0 +1,38 @@
+const path = require('path');
+const chai = require('chai');
+const encoder = require(path.join(__dirname, '..', 'src', 'encoder.js'));
+const base = require('./base.js');
+const LoraMessage = require(path.join(__dirname, '..', 'src', 'LoraMessage.js'));
+
+chai.should();
+
+describe('LoraMessage', () => {
+
+  it('should be possible to construct a simple message', () => {
+    const m = new LoraMessage(encoder);
+    m.addUnixtime(base.unixtime);
+    m.getLength().should.equal(4);
+    m.getBytes().should.deep.equal(base.unixtimeBytes);
+  });
+
+  it('should be possible to chain message parts', () => {
+    new LoraMessage(encoder)
+      .addLatLng(base.latLng[0], base.latLng[1])
+      .addUnixtime(base.unixtime)
+      .addUint16(base.uint16)
+      .addTemperature(base.temp)
+      .addUint8(base.uint8)
+      .addHumidity(base.humidity)
+      .getBytes()
+      .should.be.deep.equal(
+        Buffer.concat([
+          base.latLngBytes,
+          base.unixtimeBytes,
+          base.uint16Bytes,
+          base.tempBytes,
+          base.uint8Bytes,
+          base.humidityBytes
+        ])
+    );
+  });
+});