feat(fastify): Do not crash if enableVersioning is not used

integration/versioning/e2e/default-versioning.spec.ts

@@ -0,0 +1,98 @@
+import { INestApplication, VersioningType } from '@nestjs/common';
+import {
+  FastifyAdapter,
+  NestFastifyApplication,
+} from '@nestjs/platform-fastify';
+import { Test } from '@nestjs/testing';
+import * as request from 'supertest';
+import { AppModule } from '../src/app.module';
+
+/**
+ * `.enableVersioning()` uses `VersioningType.URI` type by default
+ * Regression test for #13496
+ * @see [Versioning](https://docs.nestjs.com/techniques/versioning)
+ */
+describe('Default Versioning behavior', () => {
+  // ======================================================================== //
+  describe('Express', () => {
+    let app: INestApplication;
+    before(async () => {
+      const moduleRef = await Test.createTestingModule({
+        imports: [AppModule],
+      }).compile();
+
+      app = moduleRef.createNestApplication();
+      app.enableVersioning();
+      await app.init();
+    });
+
+    describe('GET /', () => {
+      it('V1', () => {
+        return request(app.getHttpServer())
+          .get('/v1')
+          .expect(200)
+          .expect('Hello World V1!');
+      });
+
+      it('No Version', () => {
+        return request(app.getHttpServer()).get('/').expect(404);
+      });
+    });
+
+    describe('GET /neutral', () => {
+      it('No Version', () => {
+        return request(app.getHttpServer())
+          .get('/neutral')
+          .expect(200)
+          .expect('Neutral');
+      });
+    });
+
+    after(async () => {
+      await app.close();
+    });
+  });
+
+  // ======================================================================== //
+  describe('Fastify', () => {
+    let app: INestApplication;
+    before(async () => {
+      const moduleRef = await Test.createTestingModule({
+        imports: [AppModule],
+      }).compile();
+
+      app = moduleRef.createNestApplication<NestFastifyApplication>(
+        new FastifyAdapter(),
+      );
+      app.enableVersioning();
+      await app.init();
+      await app.getHttpAdapter().getInstance().ready();
+    });
+
+    describe('GET /', () => {
+      it('V1', () => {
+        return request(app.getHttpServer())
+          .get('/v1')
+          .expect(200)
+          .expect('Hello World V1!');
+      });
+
+      it('No Version', () => {
+        return request(app.getHttpServer()).get('/').expect(404);
+      });
+    });
+
+    describe('GET /neutral', () => {
+      it('No Version', () => {
+        return request(app.getHttpServer())
+          .get('/neutral')
+          .expect(200)
+          .expect('Neutral');
+      });
+    });
+
+    after(async () => {
+      await app.close();
+    });
+  });
+});

packages/platform-fastify/adapters/fastify-adapter.ts

@@ -126,7 +126,7 @@ export class FastifyAdapter<
 
   private _isParserRegistered: boolean;
   private isMiddieRegistered: boolean;
-  private versioningOptions: VersioningOptions;
+  private versioningOptions?: VersioningOptions;
   private readonly versionConstraint = {
     name: 'version',
     validate(value: unknown) {
@@ -166,7 +166,7 @@ export class FastifyAdapter<
     },
     deriveConstraint: (req: FastifyRequest) => {
       // Media Type (Accept Header) Versioning Handler
-      if (this.versioningOptions.type === VersioningType.MEDIA_TYPE) {
+      if (this.versioningOptions?.type === VersioningType.MEDIA_TYPE) {
         const MEDIA_TYPE_HEADER = 'Accept';
         const acceptHeaderValue: string | undefined = (req.headers?.[
           MEDIA_TYPE_HEADER
@@ -181,7 +181,7 @@ export class FastifyAdapter<
           : acceptHeaderVersionParameter.split(this.versioningOptions.key)[1];
       }
       // Header Versioning Handler
-      else if (this.versioningOptions.type === VersioningType.HEADER) {
+      else if (this.versioningOptions?.type === VersioningType.HEADER) {
         const customHeaderVersionParameter: string | string[] | undefined =
           req.headers?.[this.versioningOptions.header] ||
           req.headers?.[this.versioningOptions.header.toLowerCase()];
@@ -191,7 +191,7 @@ export class FastifyAdapter<
           : customHeaderVersionParameter;
       }
       // Custom Versioning Handler
-      else if (this.versioningOptions.type === VersioningType.CUSTOM) {
+      else if (this.versioningOptions?.type === VersioningType.CUSTOM) {
         return this.versioningOptions.extractor(req);
       }
       return undefined;