vonagam · Dec 13, 2021 · Jan 2, 2022
diff --git a/packages/feathers/src/application.ts b/packages/feathers/src/application.ts
@@ -15,7 +15,8 @@ import {
   HookOptions,
   FeathersService,
   HookMap,
-  RegularHookMap
+  RegularHookMap,
+  Setup
 } from './declarations';
 import { enableRegularHooks } from './hooks/regular';
 
@@ -32,6 +33,7 @@ export class Feathers<Services, Settings> extends EventEmitter implements Feathe
   };
 
   private regularHooks: (this: any, allHooks: any) => any;
+  private setups: Setup<this>[] = [];
 
   constructor () {
     super();
@@ -106,14 +108,21 @@ export class Feathers<Services, Settings> extends EventEmitter implements Feathe
     // Add all the mixins
     this.mixins.forEach(fn => fn.call(this, protoService, location, serviceOptions));
 
-    // If we ran setup already, set this service up explicitly, this will not `await`
-    if (this._isSetup && typeof protoService.setup === 'function') {
-      debug(`Setting up service for \`${location}\``);
-      protoService.setup(this, location);
-    }
-
     this.services[location] = protoService;
 
+    if (typeof protoService.setup === 'function') {
+      const setup = () => {
+        debug(`Setting up service for \`${location}\``);
+        return protoService.setup(this, location);
+      };
+
+      if (this._isSetup) {
+        setup(); // If we ran setup already, set this service up explicitly, this will not `await`
+      } else {
+        this.addSetup(setup);
+      }
+    }
+
     return this;
   }
 
@@ -139,25 +148,23 @@ export class Feathers<Services, Settings> extends EventEmitter implements Feathe
     return this;
   }
 
-  setup () {
-    let promise = Promise.resolve();
+  addSetup (setup: Setup<this>) {
+    if (this._isSetup) {
+      throw new Error(`Cannot add a setup step after app.setup() was called.`);
+    }
 
-    // Setup each service (pass the app so that they can look up other services etc.)
-    for (const path of Object.keys(this.services)) {
-      promise = promise.then(() => {
-        const service: any = this.service(path as any);
+    this.setups.push(setup);
 
-        if (typeof service.setup === 'function') {
-          debug(`Setting up service for \`${path}\``);
+    return this;
+  }
 
-          return service.setup(this, path);
-        }
-      });
-    }
+  setup (server?: any) {
+    this._isSetup = true;
 
-    return promise.then(() => {
-      this._isSetup = true;
-      return this;
-    });
+    const promise = this.setups.reduce((promise, setup) => {
+      return promise.then(() => setup(this, server));
+    }, Promise.resolve());
+
+    return promise.then(() => this);
   }
 }
diff --git a/packages/feathers/src/declarations.ts b/packages/feathers/src/declarations.ts
@@ -209,6 +209,8 @@ export interface FeathersApplication<Services = any, Settings = any> {
     path: L
   ): FeathersService<this, keyof any extends keyof Services ? Service : Services[L]>;
 
+  addSetup (setup: Setup<this>): this;
+
   setup (server?: any): Promise<this>;
 
   /**
@@ -361,3 +363,5 @@ export type HookMap<A, S> = {
 
 export type HookOptions<A, S> =
   HookMap<A, S> | HookFunction<A, S>[] | RegularHookMap<A, S>;
+
+export type Setup<A = Application> = (app: A, server?: any) => void | Promise<void>;
diff --git a/packages/feathers/test/application.test.ts b/packages/feathers/test/application.test.ts
@@ -315,6 +315,31 @@ describe('Feathers application', () => {
       assert.strictEqual(setupCount, 2);
     });
 
+    it('app.setup calls functions passed to .addSetup', async () => {
+      const app = feathers();
+      const server = {};
+      let setupCount = 0;
+
+      const funcSetup = (count: number) => (appRef: typeof app, serverRef: any) => {
+        assert.strictEqual(setupCount++, count);
+        assert.strictEqual(appRef, app);
+        assert.strictEqual(serverRef, server);
+      };
+      const serviceSetup = (count: number) => async () => {
+        assert.strictEqual(setupCount++, count);
+      };
+
+      app.addSetup(funcSetup(0));
+      app.use('/first', { setup: serviceSetup(1) });
+      app.addSetup(funcSetup(2));
+      app.use('/second', { setup: serviceSetup(3) });
+      app.addSetup(funcSetup(4));
+      assert.strictEqual(setupCount, 0);
+
+      await app.setup(server);
+      assert.strictEqual(setupCount, 5);
+    });
+
     it('registering a service after app.setup will be set up', done => {
       const app = feathers();