feat: 导入 NMEA-0183 GPS 协议解析库（node-nmea）

NMEA-0183 语句解析器，含 21 个语句类型 codec 与配套单元测试。

- codecs/：APB/BWC/DBT/GGA/GLL/GRMT/GSA/GSV/HDG/HDM/HDT/MWV/RDID/
  RMB/RMC/ROT/RSA/TXT/VTG/VWR/ZDA
- test/：各 codec 对应的 mocha 用例
- .github/workflows/：node与 npm-publish 流水线

许可证：MIT（原作者 James Penn）

nmea.js

@@ -0,0 +1,124 @@
+// A NMEA-0183 parser based on the format given here: http://www.tronico.fi/OH6NT/docs/NMEA0183.pdf
+
+var MWV = require('./codecs/MWV.js');
+var VTG = require('./codecs/VTG.js');
+var DBT = require('./codecs/DBT.js');
+var GLL = require('./codecs/GLL.js');
+var BWC = require('./codecs/BWC.js');
+var GSV = require('./codecs/GSV.js');
+var GSA = require('./codecs/GSA.js');
+var GGA = require('./codecs/GGA.js');
+var RMB = require('./codecs/RMB.js');
+var RMC = require('./codecs/RMC.js');
+var RSA = require('./codecs/RSA.js');
+var APB = require('./codecs/APB.js');
+var HDG = require('./codecs/HDG.js');
+var HDT = require('./codecs/HDT.js');
+var HDM = require('./codecs/HDM.js');
+var RDID = require('./codecs/RDID.js');
+var GRMT = require('./codecs/GRMT.js');
+var VWR = require('./codecs/VWR.js');
+var ROT = require('./codecs/ROT.js');
+var ZDA = require('./codecs/ZDA.js');
+var TXT = require('./codecs/TXT.js');
+
+// export helpers
+module.exports.Helpers= require('./helpers.js');
+
+var validLine = function (line) {
+  // check that the line passes checksum validation
+  // checksum is the XOR of all characters between $ and * in the message.
+  // checksum reference is provided as a hex value after the * in the message.
+  var checkVal = 0;
+  var parts = line.split('*');
+  for (var i = 1; i < parts[0].length; i++) {
+    checkVal = checkVal ^ parts[0].charCodeAt(i);
+  }
+  ;
+  return checkVal == parseInt(parts[1], 16);
+};
+
+exports.traditionalDecoders = {
+  GGA: GGA.decode,
+  RMB: RMB.decode,
+  RMC: RMC.decode,
+  RSA: RSA.decode,
+  APB: APB.decode,
+  GSA: GSA.decode,
+  GSV: GSV.decode,
+  BWC: BWC.decode,
+  DBT: DBT.decode,
+  MWV: MWV.decode,
+  VTG: VTG.decode,
+  GLL: GLL.decode,
+  HDG: HDG.decode,
+  HDT: HDT.decode,
+  HDM: HDM.decode,
+  RDID: RDID.decode,
+  GRMT: GRMT.decode,
+  VWR: VWR.decode,
+  ROT: ROT.decode,
+  ZDA: ZDA.decode,
+  TXT: TXT.decode,
+};
+
+exports.encoders = new Object();
+
+exports.encoders[MWV.TYPE] = MWV;
+exports.encoders[VTG.TYPE] = VTG;
+exports.encoders[DBT.TYPE] = DBT;
+exports.encoders[GLL.TYPE] = GLL;
+exports.encoders[HDT.TYPE] = HDT;
+exports.encoders[GGA.TYPE] = GGA;
+exports.encoders[HDM.TYPE] = HDM;
+exports.encoders[ROT.TYPE] = ROT;
+exports.encoders[ZDA.TYPE] = ZDA;
+exports.encoders[TXT.TYPE] = TXT;
+
+exports.parse = function (line) {
+  if (validLine(line)) {
+    var fields = line.split('*')[0].split(','),
+      talker_id,
+      msg_fmt;
+    if (fields[0].charAt(1) == 'P') {
+      talker_id = 'P'; // Proprietary
+      msg_fmt = fields[0].substr(2);
+    } else {
+      talker_id = fields[0].substr(1, 2);
+      msg_fmt = fields[0].substr(3);
+    }
+    var parser = exports.traditionalDecoders[msg_fmt];
+    if (parser) {
+      var val = parser(fields);
+      val.talker_id = talker_id;
+      return val;
+    } else {
+      throw Error("Error in parsing:" + line);
+    }
+  } else {
+    throw Error("Invalid line:" + line);
+  }
+};
+
+exports.encode = function (talker, msg) {
+  if (typeof msg === 'undefined') {
+    throw new Error("Can not encode undefined, did you forget msg parameter?");
+  }
+  encoder = exports.encoders[msg.type];
+  if (encoder) {
+    return encoder.encode(talker, msg);
+  } else {
+    throw Error("No encoder for type:" + msg.type);
+  }
+}
+
+exports.createDefaultTransformer = function (options) {
+  var stream = require('through')(function (data) {
+    try {
+      stream.queue(exports.parse(data));
+    } catch (e) {
+    }
+  });
+  return stream;
+};
+