Firestoreの特定のコレクションのドキュメントを全削除するスクリプト(TypeScript版)

batch_delete.ts

// See: https://firebase.google.com/docs/firestore/manage-data/delete-data#collections

export async function deleteCollection(collectionRef: CollectionReference, batchSize: number = 500) {
  const firestore = admin.firestore();
  const query = collectionRef.orderBy('__name__').limit(batchSize);
  await deleteQueryBatch(firestore, query, batchSize);
}

async function deleteQueryBatch(firestore: FirebaseFirestore.Firestore, query: Query, batchSize: number): Promise<void> {
  const snapshot = await query.get();

  // When there are no documents left, we are done
  if (snapshot.size === 0) {
    return;
  }

  // Delete documents in a batch
  const results = await execute(async (batch) => {
    snapshot.docs.forEach((doc) => {
      batch.delete(doc.ref);
    });
  });
  console.log(`deleted count: ${results.length}`);
  
  return await deleteQueryBatch(firestore, query, batchSize);
}

export async function execute(f: (batch: WriteBatch) => Promise<void>): Promise<WriteResult[]> {
  const batch = admin.firestore().batch();
  await f(batch);
  return await batch.commit();
}