@solana/web3.js - requesting a connection.close() method

[mikemaccana]

Problem

My understanding (from looking at the methods available on the connection object) is there's no way to explicitly close the TCP socket that @solana/web3.js makes to the validator. This doesn't affect anything on production - as the socket is open pretty much all the time - but nearly all test suites will complain with open handles warning unless the socket is explicitly closed.

Integration tests which use @solana/web3.js will complain with something like:

Jest has detected the following 2 open handles potentially keeping Jest from exiting:

  ●  TCPWRAP

      260 |   test(`Get all Bob's token accounts`, async () => {
      261 |     // See https://solana.stackexchange.com/questions/1685/how-do-i-prevent-open-handles-issues-when-using-the-solana-connection-object
    > 262 |     const tokenAccounts = await connection.getTokenAccountsByOwner(
          |                                            ^
      263 |       bob.publicKey,
      264 |       {
      265 |         programId: TOKEN_PROGRAM_ID,

      at node_modules/@solana/web3.js/node_modules/node-fetch/lib/index.js:1468:15
      at Function.fetch [as default] (node_modules/@solana/web3.js/node_modules/node-fetch/lib/index.js:1437:9)
      at fetchImpl (node_modules/@solana/web3.js/src/fetch-impl.ts:12:16)
      at ClientBrowser.fetch [as callServer] (node_modules/@solana/web3.js/src/connection.ts:1173:23)
      at ClientBrowser.Object.<anonymous>.ClientBrowser.request (node_modules/jayson/lib/client/browser/index.js:102:8)
      at request (node_modules/@solana/web3.js/src/connection.ts:1212:14)
      at Connection._rpcRequest (node_modules/@solana/web3.js/src/connection.ts:1211:12)
      at Connection._rpcRequest [as getTokenAccountsByOwner] (node_modules/@solana/web3.js/src/connection.ts:2757:34)
      at Object.<anonymous> (src/tokens.test.ts:262:44)

Proposed Solution

We add a close() method to the Connection object. I'm happy to do this myself if needed (I just want to make sure there's no existing way to close the connection that I have missed first).

[steveluscher]

Thanks! Tracked in #25069.