foldKanafunction

Fold text for a Japanese search: width and compatibility forms (NFKC: half-width katakana becomes full-width), hiragana to katakana, and a small kana (ッ, ャ, ァ) to its full-size one. The long-vowel mark ー is left as it is, and so is everything that is not kana (letter case is the caller's, as it is for any search). Put it on both sides of a comparison: foldKana("はっぶる") === foldKana("ハッブル"), and ハッブル is also ハツブル after it, so a reader who types a small kana as a full-size one still finds it.

import { foldKana } from "@johnmorrisdotca/chikyu-earth/satellites";

function foldKana(text: string): string

import { foldKana } from "@johnmorrisdotca/chikyu-earth/satellites";

console.log(foldKana("はっぶる") === foldKana("ハッブル"));
console.log(foldKana("ほし ー"));

true
ホシ ー