When you call
```
<span>const singleValue = convertToSingleValueData</span><span>(</span>{<br> indexRange: [0, 0],<br> mappings: { x: { type: 'undefined', types: undefined } },<br>}<span>, </span><span>0</span><span>,{ x: undefined }</span> <span>"x"</span><span>, </span><span>true</span><span>);<br><br>if (single.value === undefined) // ESLint: Unnecessary conditional, the types have no overlap.(@typescript-eslint/no-unnecessary-condition)</span>
Result of `convertToSingleValueData` looks like:
<span>export interface </span><span>SingleValueData </span><span>{<br></span> <span>/** The dimension identifier */<br></span> dimension<span>: string</span><span>;<br></span> <span>/** The value for the dimension */<br></span> value<span>: string | number</span><span>;<br></span> <span>/** The timeseries for the sparkline */<br></span> timeseries<span>?: </span><span>TimeseriesWithDimensions</span><span>[];<br></span><span>}<br></span>
value is typed as a string or number, however is not true, and it might be undefined as well.