Return audio file if exists

packages/text-to-speech/src/index.ts

@@ -86,6 +86,25 @@ export const createGCSFile = (bucket: string, filename: string): File => {
   return storage.bucket(bucket).file(filename)
 }
 
+export const listGCSFiles = async (
+  bucket: string,
+  prefix: string
+): Promise<string[]> => {
+  const [files] = await storage.bucket(bucket).getFiles({
+    prefix,
+  })
+  return files.map((file) => file.name)
+}
+
+export const downloadFromBucket = async (
+  bucket: string,
+  filename: string
+): Promise<Buffer> => {
+  const file = createGCSFile(bucket, filename)
+  const [data] = await file.download()
+  return data
+}
+
 const updateSpeech = async (
   speechId: string,
   token: string,

packages/text-to-speech/src/realisticTextToSpeech.ts

@@ -54,6 +54,15 @@ export class RealisticTextToSpeech implements TextToSpeech {
     // audio file to be saved in GCS
     const audioFileName = `speech/${input.key}.mp3`
     const audioFile = createGCSFile(bucket, audioFileName)
+    if (await audioFile.exists()) {
+      console.debug('Audio file already exists')
+      const [audioData] = await audioFile.download()
+      return {
+        audioData,
+        speechMarks: [],
+      }
+    }
+
     const outputStream = audioFile.createWriteStream({
       resumable: true,
     }) as PassThrough