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

dev-packages/node-integration-tests/suites/tracing/lru-memoizer/instrument-orchestrion.mjs

@@ -0,0 +1,17 @@
+// Opting in via `experimentalUseDiagnosticsChannelInjection()` (before `init`)
+// is all that's needed.
+//
+// `Sentry.init()` swaps the OTel `lru-memoizer` instrumentation
+// for the diagnostics-channel one and synchronously
+// installs the module hooks that inject the channels.
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.experimentalUseDiagnosticsChannelInjection();
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  release: '1.0',
+  tracesSampleRate: 1.0,
+  transport: loggingTransport,
+});

dev-packages/node-integration-tests/suites/tracing/lru-memoizer/test.ts

@@ -7,51 +7,97 @@ describe('lru-memoizer', () => {
     cleanupChildProcesses();
   });
 
-  createEsmAndCjsTests(
-    __dirname,
-    'scenario.mjs',
-    'instrument.mjs',
-    (createTestRunner, test) => {
-      test('keeps outer context inside the memoized inner functions', async () => {
-        await createTestRunner()
-          .expect({
+  // Each case maps to the OpenTelemetry default and the diagnostics-channel opt-in
+  // variants, mirroring the mysql suite. `flags` are extra Node CLI flags; the
+  // instrument file is always loaded via `--import` (esm) / `--require` (cjs).
+  //
+  // lru-memoizer creates no spans, so there's no `sentry.origin` to
+  // assert: the opt-in cases prove the channel ran because the opt-in removes the
+  // OTel integration via `replacedOtelIntegrationNames`.
+  const CASES = [
+    // OpenTelemetry default — no opt-in, no injection. (OTel does not support ESM.)
+    { label: 'opentelemetry (default)', instrument: 'instrument.mjs', flags: [], failsOnEsm: true },
+    // Opt-in via init only. `Sentry.init()` injects the channels synchronously.
+    {
+      label: 'diagnostics-channel (init opt-in)',
+      instrument: 'instrument-orchestrion.mjs',
+      flags: [],
+      failsOnEsm: false,
+    },
+    // Opt-in and rely on `node --import @sentry/node/import`.
+    {
+      label: 'diagnostics-channel (--import @sentry/node/import opt-in)',
+      instrument: 'instrument-orchestrion.mjs',
+      flags: ['--import', '@sentry/node/import'],
+      failsOnEsm: false,
+    },
+    // Without opt-in: channels are injected unconditionally but not subscribed to,
+    // so the OTel instrumentation does the work — proves injecting the channels has
+    // no downside. (OTel does not support ESM.)
+    {
+      label: 'opentelemetry (channels injected, no opt-in)',
+      instrument: 'instrument.mjs',
+      flags: ['--import', '@sentry/node/import'],
+      failsOnEsm: true,
+    },
+  ] as const;
+
+  for (const { label, instrument, flags, failsOnEsm } of CASES) {
+    describe(label, () => {
+      createEsmAndCjsTests(
+        __dirname,
+        'scenario.mjs',
+        instrument,
+        (createTestRunner, test) => {
+          test('keeps outer context inside the memoized inner functions', async () => {
+            await createTestRunner()
+              .withFlags(...flags)
+              .expect({
+                transaction: {
+                  transaction: '<unknown>',
+                  contexts: {
+                    trace: expect.objectContaining({
+                      op: 'run',
+                      data: expect.objectContaining({
+                        'sentry.op': 'run',
+                        'sentry.origin': 'manual',
+                        'memoized.context_preserved': true,
+                      }),
+                    }),
+                  },
+                },
+              })
+              .start()
+              .completed();
+          });
+        },
+        { failsOnEsm },
+      );
+
+      // CJS-only: the parallel scenario is flaky in ESM (see #21729).
+      createCjsTests(__dirname, 'scenario-parallel.mjs', instrument, (createTestRunner, test) => {
+        test('keeps each span context across parallel memoized requests', async () => {
+          // Each parallel request emits a transaction whose callback must have run in its own context.
+          // Two identical expectations keep this order-independent.
+          const expectation = {
             transaction: {
-              transaction: '<unknown>',
               contexts: {
                 trace: expect.objectContaining({
-                  op: 'run',
-                  data: expect.objectContaining({
-                    'sentry.op': 'run',
-                    'sentry.origin': 'manual',
-                    'memoized.context_preserved': true,
-                  }),
+                  op: expect.stringMatching(/^(first|second)$/),
+                  data: expect.objectContaining({ 'memoized.context_preserved': true }),
                 }),
               },
             },
-          })
-          .start()
-          .completed();
-      });
-    },
-    { failsOnEsm: true },
-  );
-
-  createCjsTests(__dirname, 'scenario-parallel.mjs', 'instrument.mjs', (createTestRunner, test) => {
-    test('keeps each span context across parallel memoized requests', async () => {
-      // Each parallel request emits a transaction whose callback must have run in its own context.
-      // Two identical expectations keep this order-independent.
-      const expectation = {
-        transaction: {
-          contexts: {
-            trace: expect.objectContaining({
-              op: expect.stringMatching(/^(first|second)$/),
-              data: expect.objectContaining({ 'memoized.context_preserved': true }),
-            }),
-          },
-        },
-      };
+          };
 
-      await createTestRunner().expect(expectation).expect(expectation).start().completed();
+          await createTestRunner()
+            .withFlags(...flags)
+            .expect(expectation)
+            .expect(expectation)
+            .start()
+            .completed();
+        });
+      });
     });
-  });
+  }
 });

packages/node/src/sdk/experimentalUseDiagnosticsChannelInjection.ts

@@ -1,4 +1,8 @@
-import { mysqlChannelIntegration, detectOrchestrionSetup } from '@sentry/server-utils/orchestrion';
+import {
+  mysqlChannelIntegration,
+  lruMemoizerChannelIntegration,
+  detectOrchestrionSetup,
+} from '@sentry/server-utils/orchestrion';
 import { registerDiagnosticsChannelInjection } from '@sentry/server-utils/orchestrion/register';
 import type { DiagnosticsChannelInjection } from './diagnosticsChannelInjection';
 import { setDiagnosticsChannelInjectionLoader } from './diagnosticsChannelInjection';
@@ -38,8 +42,8 @@ import { setDiagnosticsChannelInjectionLoader } from './diagnosticsChannelInject
 export function experimentalUseDiagnosticsChannelInjection(): void {
   setDiagnosticsChannelInjectionLoader(
     (): DiagnosticsChannelInjection => ({
-      integrations: [mysqlChannelIntegration()],
-      replacedOtelIntegrationNames: ['Mysql'],
+      integrations: [mysqlChannelIntegration(), lruMemoizerChannelIntegration()],
+      replacedOtelIntegrationNames: ['Mysql', 'LruMemoizer'],
       register: registerDiagnosticsChannelInjection,
       detect: detectOrchestrionSetup,
     }),

packages/server-utils/src/integrations/tracing-channel/lru-memoizer.ts

@@ -0,0 +1,65 @@
+import * as diagnosticsChannel from 'node:diagnostics_channel';
+import type { IntegrationFn } from '@sentry/core';
+import { debug, defineIntegration, getCurrentScope, withScope } from '@sentry/core';
+import { DEBUG_BUILD } from '../../debug-build';
+import { CHANNELS } from '../../orchestrion/channels';
+
+// Same name as the OTel integration by design — when enabled, the OTel
+// 'LruMemoizer' integration is omitted from the default set.
+const INTEGRATION_NAME = 'LruMemoizer';
+
+interface LruMemoizerChannelContext {
+  arguments: unknown[];
+}
+
+const _lruMemoizerChannelIntegration = (() => {
+  return {
+    name: INTEGRATION_NAME,
+    setupOnce() {
+      // `tracingChannel` is unavailable before Node 18.19 — no-op instead of throwing (#21783).
+      if (!diagnosticsChannel.tracingChannel) {
+        return;
+      }
+
+      DEBUG_BUILD && debug.log(`[orchestrion:lru-memoizer] subscribing to channel "${CHANNELS.LRU_MEMOIZER_LOAD}"`);
+      const lruMemoizerCh = diagnosticsChannel.tracingChannel(CHANNELS.LRU_MEMOIZER_LOAD);
+
+      lruMemoizerCh.subscribe({
+        start(rawCtx) {
+          const ctx = rawCtx as LruMemoizerChannelContext;
+          if (ctx.arguments.length === 0) {
+            return;
+          }
+
+          // Capture the scope while we're still synchronously inside the memoized call.
+          // lru-memoizer queues the callback and fires it later via setImmediate, where the
+          // active scope no longer reflects the caller's context.
+          const scope = getCurrentScope();
+          const cbIdx = ctx.arguments.length - 1;
+          const orchestrionWrappedCb = ctx.arguments[cbIdx];
+
+          if (typeof orchestrionWrappedCb !== 'function') {
+            return;
+          }
+
+          const wrapped = orchestrionWrappedCb as (...a: unknown[]) => unknown;
+          ctx.arguments[cbIdx] = function (this: unknown, ...args: unknown[]): unknown {
+            return withScope(scope, () => wrapped.apply(this, args));
+          };
+        },
+        end() {},
+        asyncStart() {},
+        asyncEnd() {},
+        error() {},
+      });
+    },
+  };
+}) satisfies IntegrationFn;
+
+/**
+ * EXPERIMENTAL — orchestrion-driven lru-memoizer integration. Subscribes to
+ * `orchestrion:lru-memoizer:load` (injected into `lru-memoizer/lib/async.js`'s
+ * `memoizedFunction`). Creates no spans; only re-runs the memoized callback with the
+ * caller's scope. Requires the orchestrion runtime hook or bundler plugin.
+ */
+export const lruMemoizerChannelIntegration = defineIntegration(_lruMemoizerChannelIntegration);

packages/server-utils/src/orchestrion/channels.ts

@@ -13,6 +13,7 @@
  */
 export const CHANNELS = {
   MYSQL_QUERY: 'orchestrion:mysql:query',
+  LRU_MEMOIZER_LOAD: 'orchestrion:lru-memoizer:load',
 } as const;
 
 export type ChannelName = (typeof CHANNELS)[keyof typeof CHANNELS];

packages/server-utils/src/orchestrion/config.ts

@@ -32,6 +32,12 @@ export const SENTRY_INSTRUMENTATIONS: InstrumentationConfig[] = [
     // attach `'end'`/`'error'` listeners that finish the span.
     functionQuery: { expressionName: 'query', kind: 'Auto' },
   },
+  {
+    channelName: 'load',
+    // `>=2.1.0` only: the named `function memoizedFunction()` the selector targets exists from 2.1.0
+    module: { name: 'lru-memoizer', versionRange: '>=2.1.0 <4', filePath: 'lib/async.js' },
+    functionQuery: { functionName: 'memoizedFunction', kind: 'Callback' },
+  },
 ];
 
 /**

packages/server-utils/src/orchestrion/index.ts

@@ -1,2 +1,3 @@
 export { detectOrchestrionSetup } from './detect';
 export { mysqlChannelIntegration } from '../integrations/tracing-channel/mysql';
+export { lruMemoizerChannelIntegration } from '../integrations/tracing-channel/lru-memoizer';