canonify/src/index.ts

**NOTE: This is effictively a fork of [@truestamp/canonify](https://www.npmjs.com/package/@truestamp/canonify) to fix an issue with exporting types. Since a repo could not be found, a fork/PR was not possible. All copyrights/attribution has been left in p

// Copyright © 2020-2023 Truestamp Inc. All rights reserved.

/**
 * The zeroth value gets no prepended comma
 * @hidden
 */
function hasComma(num: number): string {
  return num === 0 ? '' : ','
}

/**
 * Convert a JSON serializable object to a canonicalized string.
 * @param object The object to convert.
 * @return The canonicalized string or undefined.
 */
// eslint-disable-next-line @typescript-eslint/no-explicit-any
export function canonify(object: any): string | undefined {
  // See : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof
  if (
    object === null ||
    typeof object === 'undefined' ||
    typeof object === 'boolean' ||
    typeof object === 'number' ||
    typeof object === 'string'
  ) {
    return JSON.stringify(object)
  }

  if (typeof object === 'bigint') {
    throw new TypeError("BigInt value can't be serialized in JSON")
  }

  if (typeof object === 'function' || typeof object === 'symbol') {
    return canonify(undefined)
  }

  // Classes with a `toJSON` function, or Objects with a `toJSON` key where the value
  // is a Function are serialized using `toJSON()`.
  if (object.toJSON instanceof Function) {
    return canonify(object.toJSON())
  }

  if (Array.isArray(object)) {
    // eslint-disable-next-line @typescript-eslint/no-explicit-any
    const values = object.reduce((t: any, cv: any, ci: number): string => {
      // In Arrays, undefined, symbols, and functions are replaced with null
      const value =
        cv === undefined || typeof cv === 'symbol' || typeof cv === 'function'
          ? null
          : cv
      // total,value
      return `${t}${hasComma(ci)}${canonify(value)}`
    }, '')

    return `[${values}]`
  }

  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  const values = Object.keys(object as Record<any, any>)
    .sort()
    .reduce((t: string, cv: string): string => {
      // In Objects the key:value is not added if value is undefined, symbol, or function.
      if (
        object[cv] === undefined ||
        typeof object[cv] === 'symbol' ||
        typeof object[cv] === 'function'
      ) {
        return t
      }

      // total,key:value
      return `${t}${hasComma(t.length)}${canonify(cv)}:${canonify(object[cv])}`
    }, '')
  return `{${values}}`
}