Files
mercadodevida/project/src/shared/text.ts
2026-08-21 21:10:29 +02:00

65 lines
2.7 KiB
TypeScript

/**
* Pure string utilities shared across modules.
*/
/**
* Spanish single-letter conjunctions that stay lowercase in Title Case,
* except when they are the first word of the string.
*
* Standard Spanish typography rule (RAE): preposiciones y conjunciones
* (a, con, de, e, en, o, por, u, y…) van en minúscula salvo que sean la
* primera palabra. Single-letter conjunctions are included here so a
* "Y" between two words renders correctly.
*/
const LOWERCASE_WORDS = new Set(['y', 'e', 'o', 'u']);
/**
* Convert a brand/category name to Title Case.
*
* Splits on word boundaries (space, hyphen, dot, ampersand, slash) and
* uppercases the first letter of each word, lowercasing the rest of the
* word. Punctuation and whitespace separators are preserved verbatim.
*
* Behavior:
* - If the input is ALL-CAPS (every letter is uppercase and at least one
* is lowercase-equivalent), each word is Title Cased and Spanish
* single-letter conjunctions (y/e/o/u) are lowercased unless they
* are the first word.
* - If the input has mixed case (e.g. "BioSana"), it is returned
* unchanged. This makes the function idempotent for re-application:
* a Title-Cased string is a fixed point, and a mixed-case string is
* not what we're trying to fix.
* - Empty string → empty string.
*
* @example
* toTitleCase('A.VOGEL') // 'A.Vogel'
* toTitleCase('BIOCOP') // 'Biocop'
* toTitleCase('EL GRANERO INTEGRAL') // 'El Granero Integral'
* toTitleCase('COMPLEMENTOS Y NUTRICIÓN') // 'Complementos y Nutrición'
* toTitleCase('DULCES LISSEN') // 'Dulces Lissen'
* toTitleCase('La Finestra Sul Cielo') // 'La Finestra Sul Cielo' (unchanged)
* toTitleCase('BioSana') // 'BioSana' (unchanged)
* toTitleCase('') // ''
*/
export function toTitleCase(input: string): string {
if (!input) return input;
// Only transform strings that are entirely uppercase. A mixed-case string
// is treated as already-formatted and returned verbatim.
if (input !== input.toUpperCase() || input === input.toLowerCase()) {
return input;
}
// Split keeping the delimiters so we can reconstruct the string verbatim.
const parts = input.split(/([\s.\-/&]+)/g);
let isFirstWord = true;
return parts
.map((part) => {
if (/^[\s.\-/&]+$/.test(part)) return part;
if (part.length === 0) return part;
const lower = part.toLocaleLowerCase('es-ES');
if (!isFirstWord && LOWERCASE_WORDS.has(lower)) return lower;
isFirstWord = false;
return part.charAt(0).toLocaleUpperCase('es-ES') + part.slice(1).toLocaleLowerCase('es-ES');
})
.join('');
}