feat(server-utils): Add lru-memoizer diagnostics-channel integration

[nicohrubec]

Adds an orchestrion-based lru-memoizer integration replacing the equivalent otel integration if enabled. This currently supports >=2.1.0, which should be sufficient I think since <2.1.0 is barely used anymore.

Closes #20759

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit 783398f. Configure here.}

[cursor]

Opt-in drops older lru-memoizer

Medium Severity

Calling experimentalUseDiagnosticsChannelInjection() removes the OpenTelemetry LruMemoizer integration, but orchestrion injection only targets lru-memoizer >=2.1.0. Apps on 1.3.x–2.0.x that opt in lose callback context binding with no channel replacement.

Additional Locations (1)

• packages/server-utils/src/orchestrion/config.ts#L35-L39

 

^{Reviewed by Cursor Bugbot for commit 783398f. Configure here.}

[nicohrubec]

<2.1.0 is barely used anymore so I think this should be fine: https://www.npmjs.com/package/lru-memoizer?activeTab=versions

[logaretm]

I think we should capture the whole scope, mysql integration seems to do that and is very similar to this.

Suggested change

	const wrapped = orchestrionWrappedCb as (...a: unknown[]) => unknown;
	ctx.arguments[cbIdx] = function (this: unknown, ...args: unknown[]): unknown {
	return withActiveSpan(parentSpan, () => wrapped.apply(this, args));
	};
	const scope = getCurrentScope();
	const wrapped = orchestrionWrappedCb as (...a: unknown[]) => unknown;
	ctx.arguments[cbIdx] = function (this: unknown, ...args: unknown[]): unknown {
	return withScope(scope, () => wrapped.apply(this, args));
	};

[nicohrubec]

I couldn't reproduce a case locally where it actually made a difference but I aligned it with mysql

[logaretm]

It wouldn't make a difference with spans I think, but tags and other stuff maybe. Claude came up with this test:

import * as Sentry from '@sentry/node';
import memoizer from 'lru-memoizer';

let fireLoad;
const memoized = memoizer({
  load: (_arg, cb) => { fireLoad = cb; }, // capture callback, don't resolve yet
  hash: () => 'key',
});

Sentry.startSpan({ name: 'caller' }, span => new Promise(resolve => {
  Sentry.getCurrentScope().setTag('tag', 'from-caller');   // set on caller scope

  memoized({ foo: 'bar' }, () => {
    const tags = Sentry.getCurrentScope().getScopeData().tags;
    console.log('active span preserved:', Sentry.getActiveSpan()?.spanContext().spanId === span.spanContext().spanId);
    console.log('tag preserved:        ', tags.tag === 'from-caller');
    resolve();
  });
}));