Fix api v3 users seeing gaps in CGM data (nightscout#7853)

* Change runtime cache to support item timestamp be defined in either mills or date field.

* Fix typo

* Return mills in v1 api when returning data from cache

* Also parse created_at in the cache

* Fix copy paste error

lib/api/entries/index.js

@@ -474,12 +474,19 @@ function configure (app, wares, ctx, env) {
       inMemoryCollection = ctx.cache.getData('entries');
 
       inMemoryCollection = _.sortBy(inMemoryCollection, function(item) {
-        return item.mills;
+        const age = item.mills | item.date;
+        return age;
       }).reverse();
     }
 
     if (inMemoryPossible && query.count <= inMemoryCollection.length) {
       res.entries = _.cloneDeep(_.take(inMemoryCollection,query.count));
+
+      for (let i = 0; i < res.entries.length; i++) {
+        let e = res.entries[i];
+        e.mills = e.mills || e.date;
+      }
+
       res.entries_err = null;
       return next();
     }

lib/server/cache.js

@@ -29,23 +29,31 @@ function cache (env, ctx) {
     , entries: constants.TWO_DAYS
   };
 
+  function getObjectAge(object) {
+    let age = object.mills || object.date;
+    if (isNaN(age) && object.created_at) age = Date.parse(object.created_at).valueOf();
+    return age;
+  }
+
   function mergeCacheArrays (oldData, newData, retentionPeriod) {
 
     const ageLimit = Date.now() - retentionPeriod;
 
-    var filteredOld =  filterForAge(oldData, ageLimit);
+    var filteredOld = filterForAge(oldData, ageLimit);
     var filteredNew = filterForAge(newData, ageLimit);
 
     const merged = ctx.ddata.idMergePreferNew(filteredOld, filteredNew);
 
     return _.sortBy(merged, function(item) {
-      return -item.mills;
+      const age = getObjectAge(item);
+      return -age;
     });
 
     function filterForAge(data, ageLimit) {
       return _.filter(data, function hasId(object) {
         const hasId = !_.isEmpty(object._id);
-        const isFresh = object.mills >= ageLimit;
+        const age = getObjectAge(object);
+        const isFresh = age >= ageLimit;
         return isFresh && hasId;
       });
     }