support sticker payload

Author: clairton

src/services/transformer.ts

@@ -464,6 +464,7 @@ export const toBaileysMessageContent = (payload: any, customMessageCharactersFun
     case 'audio':
     case 'document':
     case 'video':
+    case 'sticker':
       const link = payload[type].link
       if (link) {
         let mimetype: string = getMimetype(payload)

src/utils/sticker_convert.ts

@@ -0,0 +1,15 @@
+import sharp from 'sharp'
+
+type StickerConvertOptions = {
+  animated?: boolean
+}
+
+export const MAX_STICKER_BYTES = 8 * 1024 * 1024
+
+export const convertToWebpSticker = async (input: Buffer, opts: StickerConvertOptions = {}) => {
+  const image = sharp(input, { animated: !!opts.animated })
+  return image
+    .resize(512, 512, { fit: 'inside', withoutEnlargement: true })
+    .webp({ lossless: !opts.animated, quality: 80, effort: 4 })
+    .toBuffer()
+}