safer context manager default

Author: EmrysMyrddin

packages/plugins/opentelemetry/src/context-stack.ts

@@ -0,0 +1,69 @@
+import type { Logger } from '@graphql-mesh/types';
+import { trace, type Context, type ContextManager } from '@opentelemetry/api';
+import type { PromiseOrValue } from 'graphql-yoga';
+
+type Node = {
+  ctx: Context;
+  previous?: Node;
+};
+
+export class OtelContextStack {
+  #root: Node;
+  #current: Node;
+
+  constructor(root: Context) {
+    this.#root = { ctx: root };
+    this.#current = this.#root;
+  }
+
+  get current(): Context {
+    return this.#current.ctx;
+  }
+
+  get root(): Context {
+    return this.#root.ctx;
+  }
+
+  push = (ctx: Context) => {
+    this.#current = { ctx, previous: this.#current };
+  };
+
+  pop = () => {
+    this.#current = this.#current.previous ?? this.#root;
+  };
+
+  toString() {
+    let node: Node | undefined = this.#current;
+    const names = [];
+    while (node != undefined) {
+      names.push((trace.getSpan(node.ctx) as unknown as { name: string }).name);
+      node = node.previous;
+    }
+    return names.join(' -> ');
+  }
+}
+
+export function getContextManager(
+  logger: Logger,
+  useContextManager: boolean,
+  contextManager?: false | ContextManager,
+): PromiseOrValue<ContextManager | false | undefined> {
+  if (contextManager != undefined) {
+    return contextManager;
+  }
+
+  return import('@opentelemetry/context-async-hooks')
+    .then((module) => new module.AsyncLocalStorageContextManager())
+    .catch((err) => {
+      if ((err as any).code === 'ERR_MODULE_NOT_FOUND') {
+        if (useContextManager) {
+          logger.error(
+            "AsyncLocalContext is not available: can't initialize context manager. Either disable context manager usage by providing `useContextManager: false` option or a context manager in the `contextManager` option.",
+          );
+        }
+        return undefined;
+      } else {
+        throw err;
+      }
+    });
+}

packages/plugins/opentelemetry/src/context.ts

@@ -33,7 +33,7 @@ import { DisposableSymbols } from '@whatwg-node/disposablestack';
 import { type OnRequestEventPayload } from '@whatwg-node/server';
 import type { OnParamsEventPayload, YogaInitialContext } from 'graphql-yoga';
 import { ATTR_SERVICE_VERSION, SEMRESATTRS_SERVICE_NAME } from './attributes';
-import { OtelContextStack } from './context-stack';
+import { getContextManager, OtelContextStack } from './context';
 import {
   getMostSpecificState,
   withState,
@@ -246,12 +246,11 @@ export function useOpenTelemetry(
       asyncAttributes,
     );
 
-    const contextManager$ =
-      options.contextManager != undefined
-        ? options.contextManager
-        : import('@opentelemetry/context-async-hooks').then(
-            (module) => new module.AsyncLocalStorageContextManager(),
-          );
+    let contextManager$ = getContextManager(
+      pluginLogger,
+      useContextManager,
+      options.contextManager,
+    );
 
     preparation$ = mapMaybePromise(exporters$, (exporters) => {
       spanProcessors = exporters;