PostExcerpt.astro

---
// Author: Igor Dimitrijević (@igorskyflyer)

import { stripFile } from '@igor.dvlpr/strip-yaml-front-matter'
import type { Props } from './dist/Props.mjs'
import { getPlainText, isMdx, isPriorV2, isV2 } from './dist/utils.mjs'
export type { Props }

const symbolEllipsis: string = '…'
const punctuationSymbols: string[] = ['.', ',', '?', '!', ';', symbolEllipsis]

let {
  post,
  words = 40,
  maxLength = 0,
  addEllipsis = true,
  smartEllipsis = true,
  ellipsis = symbolEllipsis
} = Astro.props as Props
let postExcerpt: string = ''

if (!post || (!isPriorV2(post) && !isV2(post) && !isMdx(post))) {
  throw new TypeError('The required prop post is not valid, aborting now.')
}

if (typeof words !== 'number' || words < 0) {
  words = 40
  console.warn('The optional prop words is not valid, defaulting to 40.')
}

if (typeof maxLength !== 'number' || maxLength < 0) {
  maxLength = 0
  console.warn('The optional prop maxLength is not valid, defaulting to 0.')
}

if (typeof addEllipsis !== 'boolean') {
  addEllipsis = true
  console.warn(
    'The optional prop addEllipsis is not valid, defaulting to true.'
  )
}

if (typeof smartEllipsis !== 'boolean') {
  smartEllipsis = true
  console.warn(
    'The optional prop smartEllipsis is not valid, defaulting to true.'
  )
}

if (typeof ellipsis !== 'string' || ellipsis.length < 1) {
  ellipsis = symbolEllipsis
  console.warn('The optional prop ellipsis is not valid, defaulting to "…".')
}

if (isV2(post)) {
  // Astro >= v2 detected
  postExcerpt = post['body']
} else if (isPriorV2(post)) {
  // Astro < v2 detected
  postExcerpt = post.rawContent()
} else if (isMdx(post)) {
  // MDX file detected
  // cannot be used directly from Astro 😔
  postExcerpt = stripFile(post.file)
}

postExcerpt = postExcerpt.trim()
postExcerpt = getPlainText(postExcerpt)

if (words > 0) {
  postExcerpt = postExcerpt.split(' ').slice(0, words).join(' ')
}

if (maxLength > 0) {
  postExcerpt = postExcerpt.substring(0, maxLength)
}

if (addEllipsis) {
  const postLength: number = postExcerpt.length

  if (postLength > 0) {
    if (smartEllipsis) {
      const lastChar: string | undefined = postExcerpt.at(-1)

      if (lastChar && !punctuationSymbols.includes(lastChar)) {
        postExcerpt += ellipsis
      }
    } else {
      postExcerpt += ellipsis
    }
  }
}
---

<Fragment set:html={postExcerpt} />