collectObjectValues

README.md

This function collects object values { a: 1, b: 2 } => [1, 2] { c: { d: 3, e: 4 } } => [3, 4]

collectObjectValues.test.ts

import collectObjectValues from './collectObjectValues';

describe('collectObjectValues', () => {
  it('should collect one-dimensional object values', () => {
    const input = { a: 1, b: 2 };
    const output = [1, 2];

    expect(collectObjectValues(input)).toEqual(output);
  });

  it('should collect two-dimensional object values', () => {
    const input = { user: { firstName: 'John', surname: 'Smith' } };
    const output = ['John', 'Smith'];

    expect(collectObjectValues(input)).toEqual(output);
  });

  it('should collect three-dimensional object values', () => {
    const input = {
      user: { logs: { '2022-05-16': 'Sign up', '2022-05-17': 'Sign in' } },
    };
    const output = ['Sign up', 'Sign in'];

    expect(collectObjectValues(input)).toEqual(output);
  });

  it('should collect an object values with an array of objects', () => {
    const input = {
      users: [
        { name: 'John Smith', browser: 'Chrome' },
        { name: 'John Doe', browser: 'Firefox' },
      ],
    };
    const output = ['John Smith', 'Chrome', 'John Doe', 'Firefox'];

    expect(collectObjectValues(input)).toEqual(output);
  });

  it('should collect primitives from arrays in object', () => {
    const input = {
      users: ['John', 'Tom'],
    };
    const output = ['John', 'Tom'];

    expect(collectObjectValues(input)).toEqual(output);
  });

  it('should collect primitives from an array that are in another array that are in object', () => {
    const input = {
      users: [['John', 'Tom']],
    };
    const output = ['John', 'Tom'];

    expect(collectObjectValues(input)).toEqual(output);
  });
});

collectObjectValues.ts

/**
 * This function collects object values
 * { a: 1, b: 2 } => [1, 2]
 * { c: { d: 3, e: 4 } } => [3, 4]
 * ! It can work with objects in array but can't with array of primitives !
 */
interface ArrayType
  extends Array<
    string | number | undefined | null | object | boolean | symbol | bigint
  > {}

const collectObjectValues = (inputObject: object): Array<ArrayType> => {
  const result: Array<ArrayType> = [];

  const values = Object.values(inputObject);

  values.forEach((value): void => {
    if (typeof value === 'object' && !Array.isArray(value) && value !== null) {
      const collectedObjectValues = collectObjectValues(value);

      result.push(...collectedObjectValues);

      return;
    }

    if (Array.isArray(value)) {
      value.forEach((arrayItem): void => {
        if (typeof arrayItem === 'object' && !Array.isArray(arrayItem) && arrayItem !== null) {
          const collectedObjectValues = collectObjectValues(arrayItem);

          result.push(...collectedObjectValues);

          return;
        }

        if (Array.isArray(arrayItem)) {
          const collectedArrayValues = collectObjectValues(arrayItem);

          result.push(...collectedArrayValues);

          return;
        }

        result.push(arrayItem);
      });

      return;
    }

    result.push(value);
  });

  return result;
};

export default collectObjectValues;