Include trend data on most recent sgv entry

package.json

@@ -26,6 +26,7 @@
   },
   "devDependencies": {
     "expect.js": "0.3.x",
+    "lodash": "3.10.x",
     "mocha": "2.3.x"
   },
   "keywords": [

test/fixtures.js

@@ -1,4 +1,4 @@
-var extend = require('extend');
+var _ = require('lodash');
 
 var makeSG = module.exports.makeSG = function(sg, time) {
   time = time || "Oct 20, 2015 11:09:00";
@@ -22,7 +22,9 @@ var makeSGs = module.exports.makeSGs = function(count) {
 var data = module.exports.data = function(overrides) {
   overrides = overrides || {};
   var sgs = makeSGs(288);
-  return extend(true, {
+  return _.defaults(
+    overrides,
+    {
       "sgs" : sgs,
       "lastSG" : sgs[sgs.length - 1],
       "conduitSerialNumber" : "0",
@@ -83,5 +85,6 @@ var data = module.exports.data = function(overrides) {
       "medicalDeviceTimeAsString" : "Oct 17, 2015 09:09:14",
       "lastSGTrend" : "UP_DOUBLE",
       "lastSensorTime" : 0
-  }, overrides);
+    }
+  );
 };

test/transform.js

@@ -49,29 +49,64 @@ describe('transform()', function() {
     ).to.be(0);
   });
 
-  it('should include active insulin as "iob"', function() {
-    var pumpStatus = transform(
-      f.data({'activeInsulin': {
-        'datetime' : 'Oct 17, 2015 09:09:14',
-        'version' : 1,
-        'amount' : 1.275,
-        'kind' : 'Insulin'
-      }})
-    ).filter(function(e) { return e['type'] === 'pump_status'; })[0];
-
-    expect(pumpStatus['iob']).to.be(1.275);
+  describe('active insulin', function() {
+    it('should include active insulin as "iob"', function() {
+      var pumpStatus = transform(
+        f.data({'activeInsulin': {
+          'datetime' : 'Oct 17, 2015 09:09:14',
+          'version' : 1,
+          'amount' : 1.275,
+          'kind' : 'Insulin'
+        }})
+      ).filter(function(e) { return e['type'] === 'pump_status'; })[0];
+
+      expect(pumpStatus['iob']).to.be(1.275);
+    });
+
+    it('should ignore activeInsulin values of -1', function() {
+      var pumpStatus = transform(
+        f.data({'activeInsulin': {
+          'datetime' : 'Oct 17, 2015 09:09:14',
+          'version' : 1,
+          'amount' : -1,
+          'kind' : 'Insulin'
+        }})
+      ).filter(function(e) { return e['type'] === 'pump_status'; })[0];
+
+      expect(pumpStatus['iob']).to.be(undefined);
+    });
   });
 
-  it('should ignore activeInsulin values of -1', function() {
-    var pumpStatus = transform(
-      f.data({'activeInsulin': {
-        'datetime' : 'Oct 17, 2015 09:09:14',
-        'version' : 1,
-        'amount' : -1,
-        'kind' : 'Insulin'
-      }})
-    ).filter(function(e) { return e['type'] === 'pump_status'; })[0];
-
-    expect(pumpStatus['iob']).to.be(undefined);
+  describe('trend', function() {
+    var sgs = [
+      [95, 'Oct 20, 2015 08:05:00'],
+      [105, 'Oct 20, 2015 08:10:00'],
+      [108, 'Oct 20, 2015 08:15:00']
+    ];
+
+    function transformedSGs(valDatePairs) {
+      return transform(
+        f.data({
+          'lastSGTrend': 'UP_DOUBLE',
+          'sgs': valDatePairs.map(Function.prototype.apply.bind(f.makeSG, null))
+        })
+      ).filter(function(e) { return e['type'] === 'sgv'; });
+    }
+
+    it('should add the trend to the last sgv', function() {
+      var sgvs = transformedSGs(sgs);
+      expect(sgvs.length).to.be(3);
+      expect(sgvs[sgvs.length - 1]['sgv']).to.be(108);
+      expect(sgvs[sgvs.length - 1]['direction']).to.be('DoubleUp');
+      expect(sgvs[sgvs.length - 1]['trend']).to.be(1);
+    });
+
+    it('should not add a trend if the most recent sgv is absent', function() {
+      var sgvs = transformedSGs(sgs.concat([[0, 'Oct 20, 2015 08:20:00']]));
+      expect(sgvs.length).to.be(3);
+      expect(sgvs[sgvs.length - 1]['sgv']).to.be(108);
+      expect(sgvs[sgvs.length - 1]['direction']).to.be(undefined);
+      expect(sgvs[sgvs.length - 1]['trend']).to.be(undefined);
+    });
   });
 });

transform.js

@@ -1,11 +1,20 @@
 /* jshint node: true */
 "use strict";
 
+var extend = require('extend');
+
 var logger = require('./logger');
 
 var STALE_DATA_THRESHOLD_MINUTES = 20;
 var PUMP_STATUS_ENTRY_TYPE = 'pump_status';
 var SENSOR_GLUCOSE_ENTRY_TYPE = 'sgv';
+var CARELINK_TREND_TO_NIGHTSCOUT_TREND = {
+  'NONE': {'trend': 0, 'direction': 'NONE'},
+  'UP_DOUBLE': {'trend': 1, 'direction': 'DoubleUp'},
+  'UP': {'trend': 2, 'direction': 'SingleUp'},
+  'DOWN': {'trend': 6, 'direction': 'SingleDown'},
+  'DOWN_DOUBLE': {'trend': 7, 'direction': 'DoubleDown'}
+};
 
 function parsePumpTime(pumpTimeString, offset) {
   return Date.parse(pumpTimeString + ' ' + offset);
@@ -74,21 +83,31 @@ function pumpStatusEntry(data) {
 function sgvEntries(data) {
   var offset = guessPumpOffset(data);
 
-  if(data['sgs'] && data['sgs'].length) {
-    return data['sgs'].filter(function(entry) {
-      return entry['kind'] === 'SG' && entry['sg'] !== 0;
-    }).map(function(sgv) {
-      return addTimeToEntry(
-        parsePumpTime(sgv['datetime'], offset),
-        {
-          'type': SENSOR_GLUCOSE_ENTRY_TYPE,
-          'sgv': sgv['sg'],
-        }
-      );
-    });
-  } else {
+  if (!data['sgs'] || !data['sgs'].length) {
     return [];
   }
+
+  var sgvs = data['sgs'].filter(function(entry) {
+    return entry['kind'] === 'SG' && entry['sg'] !== 0;
+  }).map(function(sgv) {
+    return addTimeToEntry(
+      parsePumpTime(sgv['datetime'], offset),
+      {
+        'type': SENSOR_GLUCOSE_ENTRY_TYPE,
+        'sgv': sgv['sg'],
+      }
+    );
+  });
+
+  if(data['sgs'][data['sgs'].length - 1]['sg'] !== 0) {
+    sgvs[sgvs.length - 1] = extend(
+      true,
+      sgvs[sgvs.length - 1],
+      CARELINK_TREND_TO_NIGHTSCOUT_TREND[data['lastSGTrend']]
+    );
+  }
+
+  return sgvs;
 }
 
 var transform = module.exports = function(data, sgvLimit) {