Fatal exception when performing math on empty series

[Codelica]

When performing math on empty series data, the following exception is thrown:

TypeError: Cannot read property '0' of undefined
    at /var/node/apps/influxdb-timeshift-proxy/handlers.js:185:57
    at Array.forEach (native)
    at /var/node/apps/influxdb-timeshift-proxy/handlers.js:182:35
    at Array.forEach (native)
    at intercept (/var/node/apps/influxdb-timeshift-proxy/handlers.js:167:40)
    at IncomingMessage.<anonymous> (/var/node/apps/influxdb-timeshift-proxy/node_modules/express-http-proxy/index.js:123:11)
    at emitNone (events.js:91:20)
    at IncomingMessage.emit (events.js:188:7)
    at endReadableNT (_stream_readable.js:975:12)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)

Came across this with some panels that don't have historical data for the desired time shift yet (or just no data that meets other conditions). For example the json variable in intercept() may look like:

{ results:
   [ { statement_id: 0 },
     { statement_id: 1 },
     { statement_id: null, series: [Object] } ] }

Adding a conditional like the following to line 185 worked for me:

if (Array.isArray(json.results[idx].series)) json.results[idx].series[0].values = [];

Thanks!

[maxsivanov]

I'm just curious why series: [Object] -- contains Object?. Can you paste here something like JSON.stringify(json, null, 2)

[Codelica]

Sure... sorry, was just lazy and console.log'd it which doesn't expand. Here is an example from a (probably worst case) query set where neither first queries return any data. "Difference" is my MATH operation on them:

{
  "results": [
    {
      "statement_id": 0
    },
    {
      "statement_id": 1
    },
    {
      "statement_id": null,
      "series": [
        {
          "name": "Difference",
          "columns": [
            "time",
            "value"
          ],
          "values": []
        }
      ]
    }
  ]
}

Thanks for the singlestat addition, going to try that out here! 👍

[shivambhandari99]

I'm getting a similar error.
The response I get is: Cannot read property 'toLocaleString' of null