BigNumber Utils

The bignumber-utils package empowers developers to effortlessly perform accurate and reliable decimal and non-decimal arithmetic in JavaScript, leveraging the robust foundation of the bignumber.js library.

This package provides a streamlined interface for working with arbitrary-precision numbers, eliminating the limitations and potential inaccuracies associated with standard JavaScript number representation. With bignumber-utils, you can confidently handle complex calculations, financial transactions, scientific computations, and more, ensuring precise results every time.

Getting Started

Install the package:

npm install -S bignumber-utils

Examples

Handle and format large numeric values with ease:

import { getBigNumber, prettifyValue } from 'bignumber-utils';

let value = getBigNumber('1456550199.54631546987123654159');

value = processValue(value, { 
  decimalPlaces: 18, 
  roundingMode: 'ROUND_HALF_UP',
  type: 'string'
});
// '1456550199.546315469871236542'

prettifyValue(value, { format: { prefix: '$' } });
// '$1,456,550,199.55'

prettifyValue(value, { 
  processing: {
    decimalPlaces: 8,
    roundingMode: 'ROUND_HALF_DOWN'
  },
  format: { 
    groupSeparator: '.', 
    decimalSeparator: ',',
    suffix: ' BTC'
  } 
});
// '1.456.550.199,54631547 BTC'

Leverage the utility functions provided by this package:

import { getBigNumber, calculateSum, adjustByPercentage } from 'bignumber-utils';

calculateSum(
  [1, 86, '55', 46.33, '47.55', getBigNumber(8041.663321), 485, '99.11', getBigNumber(-800.654)]
);
// 8061

adjustByPercentage(56936.63, -35); // 37008.81

Access the full bignumber.js API directly using the getBigNumber function when needed for advanced operations:

import { getBigNumber, processValue } from 'bignumber-utils';

const result = getBigNumber(14513.622145123884031).dividedBy(655.1232);
processValue(result,  { decimalPlaces: 18, type: 'bignumber' });
// BigNumber(22.154034760368558158)

API Reference

Value Processors

Instantiates BigNumber from a valid numeric value.

import { BigNumber } from 'bignumber.js';
import { getBigNumber } from 'bignumber-utils';

getBigNumber(355).dividedBy(113).toString();
getBigNumber('355').dividedBy(113).toString();
getBigNumber(BigNumber(355)).dividedBy(113).toString();
// '3.14159292035398230088'

Processes and outputs a value to match the requirements specified in the configuration (if any).

import { processValue } from 'bignumber-utils';

processValue(100.585) // 100.59
processValue(110.55, { type: 'number' }) // 110.55
processValue(110.55, { type: 'string', decimalPlaces: 1 }) // '110.6'
processValue(110.55, { type: 'bignumber' }) // BigNumber(100.55)
processValue(512.155, { roundingMode: 'ROUND_CEIL' }) // 513

Generates the string representation of a value after being processed and formatted to match the requirements specified in the configuration (if any).

import { prettifyValue } from 'bignumber-utils';

prettifyValue(
  15426525.846545124, 
  { 
    processing: { 
      decimalPlaces: 8 
    }, 
    format: { 
      prefix: 'BTC ' 
    } 
  }
); 
// 'BTC 15,426,525.84654512'

Helpers

Verifies if the value is a BigNumber Instance.

import { isBigNumber, getBigNumber } from 'bignumber-utils';

isBigNumber(getBigNumber(123)); // true
isBigNumber(123); // false
isBigNumber('123'); // false

Verifies if the value is a number in any of the supported types (IBigNumberValue).

import { isNumber, getBigNumber } from 'bignumber-utils';

isNumber(NaN); // false
isNumber(getBigNumber(123)); // true
isNumber(123); // true
isNumber('123'); // true

Verifies if the value is an integer in any of the supported types (IBigNumberValue).

import { isInteger, getBigNumber } from 'bignumber-utils';

isInteger(getBigNumber(123)); // true
isInteger(getBigNumber(123.551)); // false
isInteger(54122); // true
isInteger('241.44332'); // false

Verifies if the value is a float in any of the supported types (IBigNumberValue).

import { isInteger, getBigNumber } from 'bignumber-utils';

isFloat(getBigNumber(123)); // false
isFloat(getBigNumber(123.551)); // true
isFloat(54122); // false
isFloat('241.44332'); // true

Essential Calculations

Calculates the sum for an array of values. It returns 0 if the array is empty.

import { calculateSum, getBigNumber } from 'bignumber-utils';

calculateSum([1, 86, '55', 46.33, '47.55', getBigNumber(8041.663321), 485, '99.11', getBigNumber(-800.654)]); 
// 8061

Identifies the smallest value in an array. It returns 0 if the array is empty.

import { calculateMin, getBigNumber } from 'bignumber-utils';

calculateMin([1, 86, '55', 46.33, '47.55', getBigNumber(8041.663321), 485, '99.11', getBigNumber(-800.654)]); 
// -800.65

Identifies the largest value in an array. It returns 0 if the array is empty.

import { calculateMax, getBigNumber } from 'bignumber-utils';

calculateMax([1, 86, '55', 46.33, '47.55', getBigNumber(8041.663321), 485, '99.11', getBigNumber(-800.654)]); 
// 8041.66

Calculates the mean for an array of values. It returns 0 if the array is empty.

import { calculateMean, getBigNumber } from 'bignumber-utils';

calculateMean([1, 86, '55', 46.33, '47.55', getBigNumber(8041.663321), 485, '99.11', getBigNumber(-800.654)]); 
// 895.67

Calculates the median for an array of values. It returns 0 if the array is empty.

import { calculateMedian, getBigNumber } from 'bignumber-utils';

calculateMedian([1093.55, '711.41', getBigNumber(987.13), 342, '654.99', getBigNumber(84.32), '-55.99', 25132.33,]); 
// 683.2

Percentage Calculations

Calculates the percentage change experienced by a value. Note that if the value increased, the change will be positive. Otherwise, it will be negative. If there was no change, it returns 0. Moreover, the largest decrease supported by this library is -100%. If newValue is less than or equal to 0, -100 will be returned.

import { calculatePercentageChange } from 'bignumber-utils';

calculatePercentageChange(100, 150); // 50
calculatePercentageChange(1555.6544122, 554366.123124); // 35535.56
calculatePercentageChange(745.655, 1225.446, { decimalPlaces: 4 }); // 64.3449
calculatePercentageChange(
  '5412151.54561245487451',
  '78998154125.6632113',
  { decimalPlaces: 10, type: 'string' },
); 
// '1459544.1629522691'

Changes a value by a percentage. If the % is positive, it increases the value. Otherwise, it decreases it.

import { adjustByPercentage, getBigNumber } from 'bignumber-utils';

adjustByPercentage(100, 50); // 150
adjustByPercentage(100, -50); // 50
adjustByPercentage(57700, 1); // 58277
adjustByPercentage('12.536', getBigNumber(-0.00797703), { decimalPlaces: 3 }); // 12.535

Changes a value by a percentage. If the % is positive, it increases the value. Otherwise, it decreases it.

import { calculatePercentageRepresentation } from 'bignumber-utils';

calculatePercentageRepresentation(50, 100); // 50
calculatePercentageRepresentation(100, 1000); // 10
calculatePercentageRepresentation(50, 75, { decimalPlaces: 3 }) // 66.667

Financial Calculations

Calculates the asset amount that will be received once the exchange executes.

• Example: calculateExchange(value = 100 USDT, rate = 65000 USDT/BTC) => 0.00154 BTC

import { calculateExchange } from 'bignumber-utils';

calculateExchange(100, 65000, { decimalPlaces: 5 }); // 0.00154
calculateExchange(158794.2755, 64813.99); // 2.45
calculateExchange(0.08970286, 0.05409, { decimalPlaces: 4 }); // 1.6584

Calculates the fee amount that will be charged when executing a currency exchange based on a percentage.

import { calculateExchangeFee } from 'bignumber-utils';

calculateExchangeFee(1000, 1); // 10
calculateExchangeFee(25.2774561, 0.075, { decimalPlaces: 8 }); // 0.01895809

Calculates the weighted average trade price when a position can have several entries at different prices for different amounts. If the array is empty, it returns 0.

Important: the trades' tuples must follow: [price, amount].

import { calculateWeightedEntry } from 'bignumber-utils';

calculateWeightedEntry([
  [15699.65, 0.13562],
  [15500.32, 0.24210],
  [16665.88, 0.16644],
  [19555.11, 0.2886],
  [24655.44, 0.16665],
  [22113.65, 0.2001],
  [28966.11, 0.13661],
  [33154.24, 0.1774],
  [36764.81, 0.266],
  [32145.46, 0.18546],
]);
// 24637.82

BigNumber API

Since this library is built on top of bignumber.js, whenever you invoke getBigNumber(value) or buildNumber(value, { buildType: 'bignumber' }) you can make use of any method within the BigNumber Instance.

The list of methods can be found here.

Types

BigNumber

The instance of a BigNumber. It can be generated via the constructor new BigNumber(value) or by simply invoking it as a function BigNumber(value). When using this library, it can be generated via the getBigNumber(value) function.

import { BigNumber } from 'bignumber.js';

type IBigNumber = BigNumber;

The type of rounding that will be used when processing a value. The supported modes are:

• ROUND_UP(0): rounds away from zero
• ROUND_DOWN(1): rounds towards zero
• ROUND_CEIL(2): rounds towards Infinity
• ROUND_FLOOR(3): rounds towards -Infinity
• ROUND_HALF_UP(4)*: rounds towards nearest neighbour. If equidistant, rounds away from zero (Default)
• ROUND_HALF_DOWN(5): rounds towards nearest neighbour. If equidistant, rounds towards zero
• ROUND_HALF_EVEN(6): rounds towards nearest neighbour. If equidistant, rounds towards even neighbour
• ROUND_HALF_CEIL(7): rounds towards nearest neighbour. If equidistant, rounds towards Infinity
• ROUND_HALF_FLOOR(8): rounds towards nearest neighbour. If equidistant, rounds towards -Infinity

type IBigNumberRoundingModeName = 'ROUND_UP' | 'ROUND_DOWN' | 'ROUND_CEIL' | 'ROUND_FLOOR' | 'ROUND_HALF_UP' | 'ROUND_HALF_DOWN' | 'ROUND_HALF_EVEN' | 'ROUND_HALF_CEIL' | 'ROUND_HALF_FLOOR';

type IBigNumberRoundingMode = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8;

More information:

• https://mikemcl.github.io/bignumber.js/#rounding-mode
• https://mikemcl.github.io/bignumber.js/#constructor-properties

The types that can be used to instantiate BigNumber. Moreover, any of these types can be obtained when processing a value by setting it in the configuration object (type prop).

type IBigNumberValue = string | number | BigNumber;

The configuration object that is applied to the toFormat method which is used to prettify values. Available settings are:

• prefix: string to prepend. Default: ''
• decimalSeparator: decimal separator. Default: '.'
• groupSeparator: grouping separator of the integer part. Default: ','
• groupSize: primary grouping size of the integer part. Default: 3
• secondaryGroupSize: secondary grouping size of the integer part. Default: 0
• fractionGroupSeparator: grouping separator of the fraction part. Default: ' '
• fractionGroupSize: grouping size of the fraction part. Default: 0
• suffix: string to append

type IBigNumberFormat = {
  prefix?: string;
  decimalSeparator?: string;
  groupSeparator?: string;
  groupSize?: number;
  secondaryGroupSize?: number;
  fractionGroupSeparator?: string;
  fractionGroupSize?: number;
  suffix?: string;
};

More information:

• https://mikemcl.github.io/bignumber.js/#toFor

General

When a value is processed, it can output an IBigNumberValue type in order to meet the project's requirements and overcome JavaScript's numeric limitations.

type IType = 'string' | 'number' | 'bignumber';

The configuration that will be used to process a value.

type IConfig = {
  // the maximum number of decimals that will be present in the output
  decimalPlaces: number; // Default: 2

  // determines how the value will be rounded (in case it has decimals)
  roundingMode: IBigNumberRoundingModeName; // Default: 'ROUND_HALF_UP'

  // the output's type
  type: IType; // Default: 'number'
};

A generic type that sets the return type for the function that processes value based on the provided configuration (type prop).

type IOutput<T> =
  T extends { type: 'string' } ? string
    : T extends { type: 'number' } ? number
      : T extends { type: 'bignumber' } ? IBigNumber
        : number;

Built With

• TypeScript

Running the Tests

npm run test:unit

License

MIT

Deployment

Install dependencies:

npm install

Build the library:

npm start

Publish to npm:

npm publish