fix: downshift preflightCommitment to processed when bypassing preflight checks (#2415)

# Summary

There's a bug in the `sendTransaction` RPC method where, when bypassing preflight, we nevertheless materially use the value of `preflightCommitment` to determine how to behave when sending the transaction.

If you supply _nothing_ – as you might think appropriate when _skipping_ preflight – then the default of `finalized` will be used. Far from irrelevant, such a value can actually affect the retry behaviour of the send-transaction-service (STS). Read anza-xyz/agave#483 for more detail.

In this PR, we try to get ahead of anza-xyz/agave#483 by setting this value to `processed` in the client. Until the server PR is deployed widely, this should cover those who choose to upgrade

Addresses anza-xyz/agave#479

# Test plan

```
pnpm turbo test:unit:node test:unit:browser
```

Author: steveluscher

.changeset/tricky-fishes-pull.md

@@ -0,0 +1,5 @@
+---
+'@solana/rpc-transformers': patch
+---
+
+Improve transaction sending reliability for those who skip preflight (simulation) when calling `sendTransaction`

packages/library-legacy/src/connection.ts

@@ -5895,7 +5895,9 @@ export class Connection {
     const config: any = {encoding: 'base64'};
     const skipPreflight = options && options.skipPreflight;
     const preflightCommitment =
-      (options && options.preflightCommitment) || this.commitment;
+      skipPreflight === true
+        ? 'processed' // FIXME Remove when https://github.com/anza-xyz/agave/pull/483 is deployed.
+        : (options && options.preflightCommitment) || this.commitment;
 
     if (options && options.maxRetries != null) {
       config.maxRetries = options.maxRetries;

packages/library-legacy/test/connection.test.ts

@@ -4968,6 +4968,29 @@ describe('Connection', function () {
     });
   }
 
+  // FIXME Remove when https://github.com/anza-xyz/agave/pull/483 is deployed.
+  (
+    [undefined, 'processed', 'confirmed', 'finalized'] as (
+      | Commitment
+      | undefined
+    )[]
+  ).forEach(explicitPreflightCommitment => {
+    it(`sets \`preflightCommitment\` to \`processed\` when \`skipPreflight\` is \`true\`, no matter that \`preflightCommitment\` was set to \`${explicitPreflightCommitment}\``, () => {
+      const connection = new Connection(url);
+      const rpcRequestMethod = spy(connection, '_rpcRequest');
+      connection.sendEncodedTransaction('ENCODEDTRANSACTION', {
+        ...(explicitPreflightCommitment
+          ? {preflightCommitment: explicitPreflightCommitment}
+          : null),
+        skipPreflight: true,
+      });
+      expect(rpcRequestMethod).to.have.been.calledWithExactly(
+        'sendTransaction',
+        [match.any, match.has('preflightCommitment', 'processed')],
+      );
+    });
+  });
+
   it('get largest accounts', async () => {
     await mockRpcResponse({
       method: 'getLargestAccounts',

packages/rpc-transformers/package.json

@@ -63,6 +63,7 @@
         "maintained node versions"
     ],
     "dependencies": {
+        "@solana/functional": "workspace:*",
         "@solana/rpc-types": "workspace:*",
         "@solana/rpc-spec": "workspace:*",
         "@solana/rpc-subscriptions-spec": "workspace:*"

packages/rpc-transformers/src/__tests__/params-transformer-test.ts

@@ -212,6 +212,28 @@ describe('getDefaultParamsTransformerForSolanaRpc', () => {
             },
         );
     });
+    // FIXME Remove when https://github.com/anza-xyz/agave/pull/483 is deployed.
+    it.each([undefined, 'processed', 'confirmed', 'finalized'])(
+        'sets the `preflightCommitment` to `processed` when `skipPreflight` is `true` and `preflightCommitment` is `%s` on calls to `sendTransaction`',
+        explicitPreflightCommitment => {
+            const patcher = getDefaultParamsTransformerForSolanaRpc();
+            expect(
+                patcher(
+                    [
+                        null,
+                        {
+                            // eslint-disable-next-line jest/no-conditional-in-test
+                            ...(explicitPreflightCommitment
+                                ? { preflightCommitment: explicitPreflightCommitment }
+                                : null),
+                            skipPreflight: true,
+                        },
+                    ],
+                    'sendTransaction',
+                ),
+            ).toContainEqual(expect.objectContaining({ preflightCommitment: 'processed' }));
+        },
+    );
     describe('given an integer overflow handler', () => {
         let onIntegerOverflow: jest.Mock;
         let paramsTransformer: (value: unknown) => unknown;

packages/rpc-transformers/src/params-transformer.ts

@@ -1,3 +1,4 @@
+import { pipe } from '@solana/functional';
 import { Commitment } from '@solana/rpc-types';
 
 import { applyDefaultCommitment } from './default-commitment';
@@ -32,11 +33,28 @@ export function getDefaultParamsTransformerForSolanaRpc(config?: ParamsTransform
         if (optionsObjectPositionInParams == null) {
             return patchedParams;
         }
-        return applyDefaultCommitment({
-            commitmentPropertyName: methodName === 'sendTransaction' ? 'preflightCommitment' : 'commitment',
-            optionsObjectPositionInParams,
-            overrideCommitment: defaultCommitment,
-            params: patchedParams,
-        });
+        return pipe(
+            patchedParams,
+            params =>
+                applyDefaultCommitment({
+                    commitmentPropertyName: methodName === 'sendTransaction' ? 'preflightCommitment' : 'commitment',
+                    optionsObjectPositionInParams,
+                    overrideCommitment: defaultCommitment,
+                    params,
+                }),
+            // FIXME Remove when https://github.com/anza-xyz/agave/pull/483 is deployed.
+            params =>
+                methodName === 'sendTransaction'
+                    ? applyFixForIssue479(params as [unknown, { skipPreflight?: boolean } | undefined])
+                    : params,
+        );
     };
 }
+
+// See https://github.com/anza-xyz/agave/issues/479
+function applyFixForIssue479(params: [unknown, { skipPreflight?: boolean } | undefined]) {
+    if (params[1]?.skipPreflight !== true) {
+        return params;
+    }
+    return [params[0], { ...params[1], preflightCommitment: 'processed' }, ...params.slice(2)];
+}