[Bug]: GaugeChart — "numberFormatter" typing is wrong

[janhassel]

Relevant package(s)

• @carbon/charts
• @carbon/charts-svelte
• @carbon/charts-react
• @carbon/charts-angular
• @carbon/charts-vue
• Documentation website

Carbon Charts Version

1.22.15

Which bundler are you using?

Vite

What happened and what did you expect to happen?

The type definition for options.gauge.numberFormatter for the GaugeChart is ((value: number) => string) | undefined. Despite announcing that the incoming value will be of type number, it is actually a string. This means strict equality comparisons with numbers will fail and developers either have to use loose comparisons or compare against a string which will throw a TypeScript warning.

Chart data and options (automatically formatted so no need for backticks)

{
  data: [
    {
      group: 'value',
      value: 66.67,
    },
  ],
  options: {
    gauge: {
      numberFormatter: (val) => {
        console.log(val, typeof val);

        return val.toString();
      },
    },
  },
}

JavaScript console or build output (if relevant)

66.67  "string"

StackBlitz repro

No response

IBM Application/Team (if relevant)

No response

What priority level would this be in your opinion?

P3 (Low)