nostr-tools/nip30.ts

52 lines
1.4 KiB
TypeScript

/** Regex for a single emoji shortcode. */
export const EMOJI_SHORTCODE_REGEX = /:(\w+):/
/** Regex to find emoji shortcodes in content. */
export const regex = (): RegExp => new RegExp(`\\B${EMOJI_SHORTCODE_REGEX.source}\\B`, 'g')
/** Represents a Nostr custom emoji. */
export interface CustomEmoji {
/** The matched emoji name with colons. */
shortcode: `:${string}:`
/** The matched emoji name without colons. */
name: string
}
/** Match result for a custom emoji in text content. */
export interface CustomEmojiMatch extends CustomEmoji {
/** Index where the emoji begins in the text content. */
start: number
/** Index where the emoji ends in the text content. */
end: number
}
/** Find all custom emoji shortcodes. */
export function* matchAll(content: string): Iterable<CustomEmojiMatch> {
const matches = content.matchAll(regex())
for (const match of matches) {
try {
const [shortcode, name] = match
yield {
shortcode: shortcode as `:${string}:`,
name,
start: match.index!,
end: match.index! + shortcode.length,
}
} catch (_e) {
// do nothing
}
}
}
/** Replace all emoji shortcodes in the content. */
export function replaceAll(content: string, replacer: (match: CustomEmoji) => string): string {
return content.replaceAll(regex(), (shortcode, name) => {
return replacer({
shortcode: shortcode as `:${string}:`,
name,
})
})
}