feat: add support for otel context bags

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@athenna/http",
-  "version": "5.59.0",
+  "version": "5.61.0",
   "description": "The Athenna Http server. Built on top of fastify.",
   "license": "MIT",
   "author": "João Lenon <lenon@athenna.io>",

src/handlers/FastifyHandler.ts

@@ -19,6 +19,7 @@ import { NotFoundException } from '#src/exceptions/NotFoundException'
 import type { FastifyReply, FastifyRequest, RouteHandlerMethod } from 'fastify'
 
 const otelApi = await Module.safeImport('@opentelemetry/api')
+const otelCurrentContextBagKey = Symbol.for('athenna.otel.currentContextBag')
 
 export class FastifyHandler {
   /**
@@ -132,6 +133,7 @@ export class FastifyHandler {
     }
 
     let otelContext = otelApi.context.active()
+    const bag = new Map<string | symbol, unknown>()
 
     for (const binding of Config.get('http.otel.contextBindings', [])) {
       const value = binding.resolve(ctx)
@@ -140,9 +142,12 @@ export class FastifyHandler {
         continue
       }
 
+      bag.set(binding.key, value)
       otelContext = otelContext.setValue(binding.key, value)
     }
 
+    req.data.otelCurrentContextBag = bag
+    otelContext = otelContext.setValue(otelCurrentContextBagKey as any, bag)
     req.otelContext = otelContext
 
     return otelContext as OtelContext

tests/unit/server/ServerTest.ts

@@ -13,6 +13,8 @@ import { context, createContextKey } from '@opentelemetry/api'
 import { Test, AfterEach, BeforeEach, type Context, Cleanup } from '@athenna/test'
 import { AsyncLocalStorageContextManager } from '@opentelemetry/context-async-hooks'
 
+const otelCurrentContextBagKey = Symbol.for('athenna.otel.currentContextBag')
+
 export default class ServerTest {
   @BeforeEach()
   public async beforeEach() {
@@ -266,6 +268,44 @@ export default class ServerTest {
     })
   }
 
+  @Test()
+  @Cleanup(() => Config.set('http.otel.contextEnabled', false))
+  @Cleanup(() => Config.set('http.otel.contextBindings', []))
+  public async shouldCreateAndReuseTheSameRequestContextBagAcrossTheLifecycle({ assert }: Context) {
+    const exampleIdKey = 'exampleId'
+    let requestBag: Map<string | symbol, unknown> = null
+    let terminateBag: Map<string | symbol, unknown> = null
+
+    Config.set('http.otel.contextEnabled', true)
+    Config.set('http.otel.contextBindings', [{ key: exampleIdKey, resolve: () => 'example-id-from-binding' }])
+
+    Server.terminate(() => {
+      terminateBag = context.active().getValue(otelCurrentContextBagKey as any) as Map<
+        string | symbol,
+        unknown
+      >
+    }).get({
+      url: '/test',
+      handler: async ctx => {
+        requestBag = context.active().getValue(otelCurrentContextBagKey as any) as Map<
+          string | symbol,
+          unknown
+        >
+        requestBag.set(exampleIdKey, 'example-id-from-handler')
+
+        await ctx.response.send({
+          exampleId: requestBag.get(exampleIdKey)
+        })
+      }
+    })
+
+    const response = await Server.request().get('/test')
+
+    assert.deepEqual(response.json(), { exampleId: 'example-id-from-handler' })
+    assert.strictEqual(requestBag, terminateBag)
+    assert.equal(terminateBag.get(exampleIdKey), 'example-id-from-handler')
+  }
+
   @Test()
   @Cleanup(() => Config.set('http.otel.contextEnabled', false))
   @Cleanup(() => Config.set('http.otel.contextBindings', []))
@@ -293,4 +333,45 @@ export default class ServerTest {
     assert.equal(response.statusCode, 500)
     assert.deepEqual(response.json(), { route: '/boom' })
   }
+
+  @Test()
+  @Cleanup(() => Config.set('http.otel.contextEnabled', false))
+  @Cleanup(() => Config.set('http.otel.contextBindings', []))
+  public async shouldExposeTheSameRequestContextBagInsideErrorHandlers({ assert }: Context) {
+    let requestBag: Map<string | symbol, unknown> = null
+    let errorBag: Map<string | symbol, unknown> = null
+
+    Config.set('http.otel.contextEnabled', true)
+    Config.set('http.otel.contextBindings', [{ key: 'exampleId', resolve: () => 'example-id-from-binding' }])
+
+    Server.setErrorHandler(async ctx => {
+      errorBag = context.active().getValue(otelCurrentContextBagKey as any) as Map<
+        string | symbol,
+        unknown
+      >
+
+      await ctx.response.status(500).send({
+        exampleId: errorBag.get('exampleId')
+      })
+    })
+
+    Server.get({
+      url: '/boom',
+      handler: async () => {
+        requestBag = context.active().getValue(otelCurrentContextBagKey as any) as Map<
+          string | symbol,
+          unknown
+        >
+        requestBag.set('exampleId', 'example-id-from-handler')
+
+        throw new Error('boom')
+      }
+    })
+
+    const response = await Server.request().get('/boom')
+
+    assert.equal(response.statusCode, 500)
+    assert.deepEqual(response.json(), { exampleId: 'example-id-from-handler' })
+    assert.strictEqual(requestBag, errorBag)
+  }
 }