[sqlite] add experimental promise support

[Kudo]

Why

fixes #13357
close ENG-8685

How

• originally, the callbacks for websql doesn't support Promise. when people using either 'async/async or '.then inside the callback, the statement will be executed after the "transaction end" statement.
• we should we low level control without websql at all.
• introduce low-level execAsync
• introduce transactionAsync
  usage

  const db = SQLite.openDatabase('dbName', version);
  
  const readOnly = true;
  await db.transactionAsync(async tx => {
    const result = await tx.executeSqlAsync('SELECT COUNT(*) FROM USERS', []);
    console.log('Count:', result.rows[0]['COUNT(*)']);
  }, readOnly);

  note that the result is the ResultSet type but not the SQLResultSet type. people can access the result items by rows[0] rather than rows.item(0). i was thinking to deprecate websql somehow and it doesn't make sense to wrap the result by the WebSQLResultSet again

Test Plan

add some SQLite Async unit tests and test suite ci should be passed

Checklist

• Documentation is up to date to reflect these changes (eg: https://docs.expo.dev and README.md).
• Conforms with the Documentation Writing Style Guide
• This diff will work correctly for npx expo prebuild & EAS Build (eg: updated a module plugin).

[linear]

ENG-8685 Implementing SQLite to use promises does not work on the second step in a transaction

This issue was automatically imported from GitHub: #13357

Issue accepted by kudo

---

Summary:

• User is attempting to use promises with SQLite callbacks to reduce code depth.
• Issue occurs on both Android and iOS platforms in a managed workflow with SDK version 40.
• The problem arises when the first SQL statement in a transaction is marked as "complete" using immediate.
• Executing a second SQL statement in the same transaction hangs due to the transaction being considered "complete."
• A reproducible demo is provided in an Expo Snack: https://snack.expo.io/trajano/sqlite-async

[brentvatne]

out of curiosity - how did you decide on wrapping this in an ExpoSQLTransaction class rather than inlining the execAsync here?

[Kudo]

the idea is to make transactionAsync like transaction but only for async mode. for transaction, it gives you a transaction interface and that is actually a wrapped WebSQLTransaction as well.

i'm open to the design, feel free to comment if there's any thought.

[brentvatne]

sounds reasonable, thanks for clarifying!

[Kudo]

landing this pr because it doesn't have other concerns and it's experimental.

[sean-fletching]

Hello,

Thanks for this change! I discovered the transactional problem in my code today (trying to wrap promises around it) and then discovered this thread and the new expo-sqlite 11.3.1.

I've integrated this and I noticed a few things I'd like to share; hopefully this is an OK place:

• My app now throws an error at startup

Cannot find native module 'ExpoSQLite'

and I assumed that this could be fixed by building an expo-dev-client, which it did. I didn't see this in the documentation but 11.3.1 isn't an approved SDK 48.0.0 package, so I'd assume that also means it doesn't get built into Expo Go either, at least not yet?

[Kudo]

hi there! this feature is available in sdk 49 and it's now public beta.

[mphill]

Hello,

Thanks for this change! I discovered the transactional problem in my code today (trying to wrap promises around it) and then discovered this thread and the new expo-sqlite 11.3.1.

I've integrated this and I noticed a few things I'd like to share; hopefully this is an OK place:

• My app now throws an error at startup

Cannot find native module 'ExpoSQLite'

and I assumed that this could be fixed by building an expo-dev-client, which it did. I didn't see this in the documentation but 11.3.1 isn't an approved SDK 48.0.0 package, so I'd assume that also means it doesn't get built into Expo Go either, at least not yet?

This is an interesting situation I saw too.

Make sure you install this using npx expo install expo-sqlite and not yarn add expo-sqlite. This new version of expo-sqlite will fail on expo 48.

[sean-fletching]

hi there! this feature is available in sdk 49 and it's now public beta.

Thanks! Hey I believe I found a typing error in the code here:
https://github.com/expo/expo/blob/main/packages/expo-sqlite/src/SQLite.ts#L57

This will cause errors to go unnoticed, at least for me, until I checked that the property error was on the result object and throw that result to kill a transaction. I don't want to keep your PR here running though - can I help file a bug on that or a PR?

[tanoc]

Am I wrong thinking that there should be some sort of locks (or a queue like in @expo/websql) for transactionAsync? It looks if you are running 2 concurrent transactions it could result in something like this with unexpected results:

...
BEGIN
INSERT ...
BEGIN
INSERT ...
END
ROLLBACK
...

In @expo/websql the _createTransaction function is actually appending the transaction to a queue, making every transaction independent, waiting one to finish before starting the next one.