Map "unavailable" datapoints to null. Fixes #146 (#147)

Author: dbuezas

src/cache/fetch-states.ts

@@ -44,7 +44,7 @@ async function fetchStates(
     .map((entry) => ({
       ...entry,
       timestamp: +new Date(entry.last_updated || entry.last_changed),
-      value: "", // may be state or an attribute. Will be set when getting the history
+      value: null, // may be state or an attribute. Will be set when getting the history
     }))
     .filter(({ timestamp }) => timestamp);
 }

src/cache/fetch-statistics.ts

@@ -29,7 +29,7 @@ async function fetchStatistics(
     .map((entry) => ({
       ...entry,
       timestamp: +new Date(entry.start),
-      value: "", //depends on the statistic, will be set in getHistory
+      value: null, //depends on the statistic, will be set in getHistory
     }))
     .filter(({ timestamp }) => timestamp);
 }

src/plotly-graph-card.ts

@@ -610,7 +610,9 @@ export class PlotlyGraph extends HTMLElement {
       if (isEntityIdAttrConfig(trace)) name += ` (${trace.attribute}) `;
       if (isEntityIdStatisticsConfig(trace)) name += ` (${trace.statistic}) `;
       const xsIn = history.map(({ timestamp }) => new Date(timestamp));
-      const ysIn: Datum[] = history.map(({ value }) => value);
+      const ysIn: Datum[] = history.map(({ value }) =>
+        value === "unavailable" ? null : value
+      );
 
       let xs: Datum[] = xsIn;
       let ys = ysIn;