propername

A modern, TypeScript-first npm package for sanitizing and proper casing of human names written in Latin script. Zero runtime dependencies, dual ESM + CJS output, MIT licensed.

A drop-in spiritual replacement for the abandoned namecase package.

Installation

npm install propername

Usage

import { toNameCase } from 'propername';

toNameCase('john smith');              // → 'John Smith'
toNameCase('JOHN SMITH');              // → 'John Smith'
toNameCase('ludwig van beethoven');    // → 'Ludwig van Beethoven'
toNameCase('mcdonald');               // → 'McDonald'
toNameCase('macgregor');              // → 'MacGregor'
toNameCase("o'brien");                // → "O'Brien"
toNameCase('marie-anne van der berg'); // → 'Marie-Anne van der Berg'
toNameCase('  john    smith  ');          // → 'John Smith'
toNameCase('  john    smith  ', false);  // → '  John    Smith  '

API

toNameCase(name: string, trim?: boolean): string

Converts a human name string to proper name casing.

• Splits on whitespace, hyphens (-), and apostrophe variants (', ' U+2019, ʼ U+02BC)
• Capitalizes each word, except particles which stay lowercase unless they appear at the start of the string
• Applies Mc/Mac prefix capitalization rules
• When trim is true (default), leading/trailing whitespace is removed and internal runs of whitespace are collapsed to a single space before processing

Supported conventions

Word boundaries

The following characters are treated as word boundaries (the segment after each is capitalized):

• Whitespace
• Hyphens: goodfellow-smith → Goodfellow-Smith
• Apostrophes (', ', ʼ): o'connor → O'Connor

Prefixes

| Prefix | Example input | Output | |--------|---------------|------------| | Mc | mcdonald | McDonald | | Mac | macgregor | MacGregor |

Lowercase particles

Particles are kept lowercase unless they appear as the first word of the string.

| Culture | Particles | |---------|-----------| | Dutch | van, de, den, der, ten, ter | | German | von, zu | | French / Italian / Spanish / Portuguese | de, di, da, del, della, degli, dei, las, los, le, la, l', d', dos, das, e | | Welsh | ap, ab, ferch, verch | | Arabic (romanized) | al, el, bin, bint, ibn, abu | | Scottish | of |

Out of scope (v1)

• Non-Latin scripts (Arabic, Chinese, Japanese, Korean, Cyrillic, etc.)
• Full name parsing (splitting into first / last / middle)
• Prefix/suffix handling (Mr., Dr., PhD, etc.)

License

MIT