fix(instrumentation-fastify): add missing module export

fastify v4.x+ exports an object named `errorCodes` as both a property of the default export and as a named export.

The export is documented at https://github.com/fastify/fastify/blob/4.x/docs/Reference/Errors.md?plain=1#L236.

This closes #2027.

plugins/node/opentelemetry-instrumentation-fastify/src/instrumentation.ts

@@ -27,6 +27,7 @@ import type {
   FastifyInstance,
   FastifyRequest,
   FastifyReply,
+  FastifyErrorCodes,
 } from 'fastify';
 import { hooksNamesToWrap } from './constants';
 import {
@@ -185,6 +186,7 @@ export class FastifyInstrumentation extends InstrumentationBase<FastifyInstrumen
 
   private _patchConstructor(moduleExports: {
     fastify: () => FastifyInstance;
+    errorCodes: FastifyErrorCodes;
   }): () => FastifyInstance {
     const instrumentation = this;
 
@@ -198,6 +200,7 @@ export class FastifyInstrumentation extends InstrumentationBase<FastifyInstrumen
       return app;
     }
 
+    fastify.errorCodes = moduleExports.errorCodes
     fastify.fastify = fastify;
     fastify.default = fastify;
     return fastify;

plugins/node/opentelemetry-instrumentation-fastify/test/instrumentation.test.ts

@@ -560,4 +560,10 @@ describe('fastify', () => {
       },
     });
   });
+
+  it('should expose errorCodes', async () => {
+    assert.ok(Fastify.errorCodes);
+    assert.strictEqual(typeof Fastify.errorCodes, 'object');
+    assert.ok('FST_ERR_NOT_FOUND' in Fastify.errorCodes);
+  })
 });