lowerCase function

Converts a string to lower-case words separated by spaces, splitting identifiers such as camelCase.

import { lowerCase } from 'utils';

Signature

export function lowerCase(input: string): string

Parameters

Name	Description
input	The identifier or sentence to convert, in any case style.

Returns

The words in lower case, separated by single spaces; '' when there is no word.

Example

lowerCase('engineRoomTemperature'); // 'engine room temperature'
lowerCase('MAX_SPEED'); // 'max speed'

Tests

Line coverage: 100 %.

• ✅ converts "engineRoomTemperature" to "engine room temperature"
• ✅ converts "MAX_SPEED" to "max speed"
• ✅ converts " Hello---World " to "hello world"
• ✅ converts "" to ""

Source

src/string/lower-case.ts (on GitHub)

Uses

• splitWords: Splits a string into words, whatever its case style (camelCase, kebab-case, snake_case, spaces…), in one pass.

Files it needs

src/string/lower-case.ts imports, directly or not:

• src/string/split-words.ts

Source code

import { splitWords } from './split-words';

/**
 * Converts a string to lower-case words separated by spaces, splitting identifiers such as `camelCase`.
 *
 * @param input - The identifier or sentence to convert, in any case style.
 * @returns The words in lower case, separated by single spaces; `''` when there is no word.
 * @example
 * lowerCase('engineRoomTemperature'); // 'engine room temperature'
 * lowerCase('MAX_SPEED'); // 'max speed'
 */
export function lowerCase(input: string): string {
  return splitWords(input)
    .map((word) => word.toLowerCase())
    .join(' ');
}

Test file

import { lowerCase } from './lower-case';

describe(lowerCase, () => {
  it.for([
    ['engineRoomTemperature', 'engine room temperature'],
    ['MAX_SPEED', 'max speed'],
    ['  Hello---World ', 'hello world'],
    ['', ''],
  ] as const)('converts %j to %j', ([input, expected]) => {
    expect(lowerCase(input)).toBe(expected);
  });
});

Keywords: lower, case, strings, function