How to quickly clear child database between tests?

I’m using jest to test my database’s roles and permissions. Creating a new child database between each test takes way too long and is expensive.

Is there a way to quickly clear a database between tests without deleting and recreating?

If the word quickly is crucial then deleting the test database is the fastest way since else you bump into the cache of collections/functions/index names. I’m surprised that deleting and creating a database is taking a lot of time though since for me that process takes about 1 second or less.

Could you give us a glimpse on how you are doing it? Maybe a script or something that you could give us insight to.

Here is an example of our accounts service. The delete for this database takes about 2 seconds which is excellent. However, we have to wait another 14 seconds between each test for creation.

Looking at this now, I guess I don’t need to delete roles and functions right? I can organize my collections, indexes, and tokens together and just recreate those. But what happens when we add more? I could easily see us having hundreds of collections.

// Creating a DB:

$ ts-node-dev -r dotenv/config scripts/create.ts
[INFO] 13:49:21 ts-node-dev ver. 1.1.1 (using ts-node ver. 9.1.1, typescript ver. 4.1.3)
   [ Executed ] 'database - create child database if it doesnt exist'
   [ Executed ] 'database admin key - create child database admin key'
   [ Executed ] 'collections/indexes - oauth_applications'
   [ Executed ] 'collections/indexes - oauth_codes'
   [ Executed ] 'collections/indexes - oauth_sessions'
   [ Executed ] 'collections/indexes - oauth_transactions'
   [ Executed ] 'collections/indexes - accounts'
   [ Executed ] 'functionrole - get_account_function_role'
   [ Executed ] 'functionrole - create_account_function_role'
   [ Executed ] 'functionrole - create_oauth_transaction_function_role'
   [ Executed ] 'functionrole - create_oauth_code_function_role'
   [ Executed ] 'functionrole - verify_oauth_code_function_role'
   [ Executed ] 'functionrole - verify_client_credentials_function_role'
   [ Executed ] 'functionrole - verify_refresh_token_function_role'
   [ Executed ] 'functionrole - create_access_and_refresh_token_function_role'
   [ Executed ] 'function - get_account_function'
   [ Executed ] 'function - create_account_function'
   [ Executed ] 'function - create_oauth_transaction_function'
   [ Executed ] 'function - create_oauth_code_function'
   [ Executed ] 'function - verify_oauth_code_function'
   [ Executed ] 'function - verify_client_credentials_function'
   [ Executed ] 'function - verify_refresh_token_function'
   [ Executed ] 'function - create_access_and_refresh_token_function'
   [ Executed ] 'keyrole - server_key_role'
✨  Done in 14.64s.

// Example test:

import {
} from "@booksmart/faunadb";

const { Call, UDF } = query;

describe("accounts-api", () => {
  let client: Client;

  beforeEach(async () => {
    client = await createTestDatabase("accounts-api-test");

  test("can create a new business", async () => {
    const options = {
      givenName: "John",
      familyName: "Smith",
      email: "",

    const response = await client.query(


There are multiple things that you can do here.

Group in one transaction
I’m assuming that every ‘Executed’ I see here is a separate transaction. You can combine many creations in one transaction with Do. That’ll make you run into problems once you start creating collections/indexes that depend on each other. In that case you would turn it into a Let(). For example, here is the query generated by a tool I just wrote and am going to release on npm/github shortly. Maybe I should provide a way to use it as a pure library instead of as a commandline tool as well for testing purposes.

To test the library itself I used its internal functions to set up resources, each test sets up its own database and most tests run in 1-2s.

The alternative is not to delete the database and write a CreateOrUpdate to update everything. You would still want to do that in as few transactions as possible though. For indexes, it won’t work since those have to be dropped. For a test it’s much cleaner to use child databases so I would go with the first approach.

1 Like

Congratulations on your new migration tool! I’m excited to check it out.

I’ll rework my setup to use Let. Never thought of that!