Extract code about value formats from grafana repo and did some slight changes.

$ npm install @baurine/grafana-value-formats
// or
$ yarn add @baurine/grafana-value-formats

(I publish this package to npm registry and GitHub Packages both.)

The main function is function getValueFormat(unitFormat: string): string {...}, it will return a function whose signature is below:

export type ValueFormatter = (
  value: number,
  decimals?: DecimalCount,
  scaledDecimals?: DecimalCount,
  isUtc?: boolean
) => string

Samples: (copy from valueForamts.test.ts)

// if scaledDecimals is null, use decimals
const str = getValueFormat('ms')(10000086.123, 0, null)
expect(str).toBe('3 hour')

const str = getValueFormat('ms')(10000086.123, 1, null)
expect(str).toBe('2.8 hour')

const str = getValueFormat('kbytes')(10000000, 3, null)
expect(str).toBe('9.537 GiB')

const str = getValueFormat('deckbytes')(10000000, 3, null)
expect(str).toBe('10.000 GB')

// if scaledDecimals is not null, use scaledDecimals, ignore decimals
const str = getValueFormat('ms')(1200, 0, 0)
expect(str).toBe('1.200 s')

You can find all unitFormat we can use in the categories.ts, or exported getValueFormats() function.

• Add IEC units for Data rate
• Update id of Data rate in SI units

• Use dayjs to replace momentjs

• Nothing changes, just bump version

• Add "qps" unit (#4)

1. Change a part implementation of scaledUnits() method in src/valueFormats/valueFormats.ts line 126:

   if (steps > 0 && scaledDecimals !== null && scaledDecimals !== undefined) {
     // old logic
     // decimals = scaledDecimals + 3 * steps; // 为什么是乘以 3，大概是以 factor = 1000 为准，1000 表示 3 个小数点
   
     // current logic
     // related issue: https://github.com/grafana/grafana/issues/23561
     decimals = scaledDecimals
   }

   So at before

   expect(scaler(98765, 0, 2)).toBe('98.76500K')
   // because the decimals = 1*3 + 2

   and now

   expect(scaler(98765, 0, 2)).toBe('98.77K')
   // because the decimals = 2