diff --git a/extensions/socketio/src/socketio.server.ts b/extensions/socketio/src/socketio.server.ts
index 1a5915ed92d2..6f4c668dfb24 100644
--- a/extensions/socketio/src/socketio.server.ts
+++ b/extensions/socketio/src/socketio.server.ts
@@ -152,9 +152,9 @@ export class SocketIoServer extends Context {
       this.app.bind(getNamespaceKeyForName(meta.name)).to(nsp);
     }
 
-    nsp.on('connection', socket =>
-      this.createSocketHandler(controllerClass)(socket),
-    );
+    nsp.on('connection', async socket => {
+      await this.createSocketHandler(controllerClass)(socket);
+    });
     return nsp;
   }
 
@@ -164,7 +164,7 @@ export class SocketIoServer extends Context {
    */
   private createSocketHandler(
     controllerClass: Constructor<object>,
-  ): (socket: Socket) => void {
+  ): (socket: Socket) => Promise<void> {
     return async socket => {
       debug(
         'SocketIo connected: id=%s namespace=%s',
diff --git a/packages/booter-lb3app/src/__tests__/acceptance/booter-lb3app.acceptance.ts b/packages/booter-lb3app/src/__tests__/acceptance/booter-lb3app.acceptance.ts
index 402418af143d..5410e4c96e18 100644
--- a/packages/booter-lb3app/src/__tests__/acceptance/booter-lb3app.acceptance.ts
+++ b/packages/booter-lb3app/src/__tests__/acceptance/booter-lb3app.acceptance.ts
@@ -52,7 +52,7 @@ describe('booter-lb3app', () => {
         },
       });
 
-      const schemas = (spec.components ?? {}).schemas ?? {};
+      const schemas = spec.components?.schemas ?? {};
       expect(schemas._new_CoffeeShop)
         .to.have.property('properties')
         .eql({
@@ -68,7 +68,7 @@ describe('booter-lb3app', () => {
 
     it('includes the target model as a property of the source model in a relation', async () => {
       const spec = await app.restServer.getApiSpec();
-      const schemas = (spec.components ?? {}).schemas ?? {};
+      const schemas = spec.components?.schemas ?? {};
 
       expect(schemas.CoffeeShop)
         .to.have.property('properties')
diff --git a/packages/context/src/__tests__/unit/resolver.unit.ts b/packages/context/src/__tests__/unit/resolver.unit.ts
index 93d8fa085a60..04c19b4a494d 100644
--- a/packages/context/src/__tests__/unit/resolver.unit.ts
+++ b/packages/context/src/__tests__/unit/resolver.unit.ts
@@ -631,6 +631,7 @@ describe('method injection', () => {
     let savedInstance;
     class TestClass {
       test(@inject('foo') foo: string) {
+        // eslint-disable-next-line @typescript-eslint/no-this-alias
         savedInstance = this;
         return `hello ${foo}`;
       }
@@ -647,6 +648,7 @@ describe('method injection', () => {
       bar: string;
 
       test(@inject('foo') foo: string) {
+        // eslint-disable-next-line @typescript-eslint/no-this-alias
         savedInstance = this;
         this.bar = foo;
         return `hello ${foo}`;
@@ -724,6 +726,7 @@ describe('async method injection', () => {
       bar: string;
 
       test(@inject('foo') foo: string) {
+        // eslint-disable-next-line @typescript-eslint/no-this-alias
         savedInstance = this;
         this.bar = foo;
         return Promise.resolve(`hello ${foo}`);
diff --git a/packages/eslint-config/eslintrc.js b/packages/eslint-config/eslintrc.js
index 8df08e7a8188..b3ad3f0d5ec4 100644
--- a/packages/eslint-config/eslintrc.js
+++ b/packages/eslint-config/eslintrc.js
@@ -162,20 +162,14 @@ module.exports = {
       {
         selector: 'variable',
         format: null,
-        filter: {
-          regex: '^_$',
-          match: true,
-        },
+        filter: '^_$',
       },
 
       // For mixin functions
       {
         selector: 'function',
         format: ['PascalCase'],
-        filter: {
-          regex: 'Mixin$',
-          match: true,
-        },
+        filter: 'Mixin$',
       },
 
       {
@@ -184,18 +178,6 @@ module.exports = {
         leadingUnderscore: 'allow',
       },
 
-      // For members such as `Content-Type` or `application/json` or `200`
-      {
-        selector: 'memberLike',
-        format: null,
-        filter: {
-          // you can expand this regex as you find more cases that require
-          // quoting that you want to allow
-          regex: '[0-9-/ ]',
-          match: true,
-        },
-      },
-
       // For enum members
       {
         selector: 'enumMember',
@@ -243,6 +225,13 @@ module.exports = {
         selector: 'typeLike',
         format: ['PascalCase'],
       },
+
+      {
+        selector: 'objectLiteralProperty',
+        format: null,
+        // filter: '^([2-5]{1}[0-9]{2})$|[-/ ]',
+        modifiers: ['requiresQuotes'],
+      },
     ],
   },
 
diff --git a/packages/express/src/__tests__/acceptance/test-helpers.ts b/packages/express/src/__tests__/acceptance/test-helpers.ts
index 54ba1fea9e60..f1bec173f98b 100644
--- a/packages/express/src/__tests__/acceptance/test-helpers.ts
+++ b/packages/express/src/__tests__/acceptance/test-helpers.ts
@@ -11,13 +11,22 @@ import {
 } from '@loopback/core';
 import {Client, givenHttpServerConfig, supertest} from '@loopback/testlab';
 import bodyParser from 'body-parser';
+import {NextFunction, Request, Response} from 'express';
 import {ExpressApplication} from '../../express.application';
 import {ExpressRequestHandler} from '../../types';
 import {SpyAction, SpyConfig} from '../fixtures/spy-config';
-import spyFactory from '../fixtures/spy.middleware';
-export const spy = spyFactory;
+
+export {default as spy} from '../fixtures/spy.middleware';
 export {SpyConfig} from '../fixtures/spy-config';
 
+function runAsyncWrapper(
+  callback: (req: Request, res: Response, next: NextFunction) => Promise<void>,
+): ExpressRequestHandler {
+  return function (req: Request, res: Response, next: NextFunction) {
+    callback(req, res, next).catch(next);
+  };
+}
+
 export type TestFunction = (
   spyBinding: Binding<unknown>,
   path?: string,
@@ -62,23 +71,26 @@ export class TestHelper {
       }
     }
     const binding = this.app.controller(MyController);
-    const handler: ExpressRequestHandler = async (req, res, next) => {
-      try {
-        const controller = await this.app.get<MyController>(binding.key);
-        const proxy = createProxyWithInterceptors(
-          controller,
-          this.app.expressServer.getMiddlewareContext(req),
-          undefined,
-          {
-            type: 'route',
-            value: controller,
-          },
-        );
-        res.send(await proxy.hello(req.body));
-      } catch (err) {
-        next(err);
-      }
-    };
+
+    const handler: ExpressRequestHandler = runAsyncWrapper(
+      async (req, res, next) => {
+        try {
+          const controller = await this.app.get<MyController>(binding.key);
+          const proxy = createProxyWithInterceptors(
+            controller,
+            this.app.expressServer.getMiddlewareContext(req),
+            undefined,
+            {
+              type: 'route',
+              value: controller,
+            },
+          );
+          res.send(await proxy.hello(req.body));
+        } catch (err) {
+          next(err);
+        }
+      },
+    );
     this.app.expressServer.expressApp.post('/hello', handler);
     this.app.expressServer.expressApp.post('/greet', handler);
   }
diff --git a/packages/express/src/middleware.ts b/packages/express/src/middleware.ts
index de817a835ffb..841f314d66c0 100644
--- a/packages/express/src/middleware.ts
+++ b/packages/express/src/middleware.ts
@@ -353,16 +353,23 @@ export function invokeExpressMiddleware(
  * @param ctx - Context object to discover registered middleware
  */
 export function toExpressMiddleware(ctx: Context): ExpressRequestHandler {
-  return async (req, res, next) => {
+  return (req, res, next) => {
     const middlewareCtx = new MiddlewareContext(req, res, ctx);
 
-    try {
-      const result = await invokeMiddleware(middlewareCtx);
-      if (result !== res) {
-        next();
-      }
-    } catch (err) {
-      next(err);
-    }
+    new Promise((resolve, reject) => {
+      // eslint-disable-next-line no-void
+      void (async () => {
+        try {
+          const result = await invokeMiddleware(middlewareCtx);
+          resolve(result);
+        } catch (err) {
+          reject(err);
+        }
+      })();
+    })
+      .then(result => {
+        if (result !== res) next();
+      })
+      .catch(next);
   };
 }
diff --git a/packages/monorepo/lib/config-lerna-scopes.js b/packages/monorepo/lib/config-lerna-scopes.js
index dfc0ee5d1bd4..ee892fb2422f 100644
--- a/packages/monorepo/lib/config-lerna-scopes.js
+++ b/packages/monorepo/lib/config-lerna-scopes.js
@@ -14,7 +14,7 @@ const {getPackages, runMain} = require('./script-util');
 
 module.exports = {
   rules: {
-    // https://github.com/marionebl/commitlint/blob/master/docs/reference-rules.md
+    // eslint-disable-next-line @typescript-eslint/naming-convention
     'scope-enum': async ctx => [2, 'always', await getPackageNames(ctx)],
   },
 };
diff --git a/packages/openapi-v3/src/__tests__/integration/controller-spec.integration.ts b/packages/openapi-v3/src/__tests__/integration/controller-spec.integration.ts
index 6e5d602c9f93..0ccbab1eb664 100644
--- a/packages/openapi-v3/src/__tests__/integration/controller-spec.integration.ts
+++ b/packages/openapi-v3/src/__tests__/integration/controller-spec.integration.ts
@@ -313,7 +313,7 @@ describe('controller spec', () => {
         $ref: '#/components/schemas/Todo',
       });
 
-      const globalSchemas = (spec.components ?? {}).schemas;
+      const globalSchemas = spec.components?.schemas;
       expect(globalSchemas).to.deepEqual({
         Todo: {
           title: 'Todo',
@@ -362,7 +362,7 @@ describe('controller spec', () => {
         $ref: '#/definitions/Todo',
       });
 
-      const globalSchemas = (spec.components ?? {}).schemas;
+      const globalSchemas = spec.components?.schemas;
       expect(globalSchemas).to.deepEqual({
         Todo: {
           title: 'Todo',
@@ -462,7 +462,7 @@ describe('controller spec', () => {
       }
 
       const spec = getControllerSpec(MyController);
-      const globalSchemas = (spec.components ?? {}).schemas;
+      const globalSchemas = spec.components?.schemas;
       expect(globalSchemas).to.be.undefined();
     });
 
@@ -533,7 +533,7 @@ describe('controller spec', () => {
         },
       });
 
-      const globalSchemas = (spec.components ?? {}).schemas;
+      const globalSchemas = spec.components?.schemas;
       expect(globalSchemas).to.deepEqual({
         Todo: {
           title: 'Todo',
@@ -593,7 +593,7 @@ describe('controller spec', () => {
         $ref: '#/components/schemas/Todo',
       });
 
-      const globalSchemas = (spec.components ?? {}).schemas;
+      const globalSchemas = spec.components?.schemas;
       expect(globalSchemas).to.deepEqual({
         Todo: {
           title: 'Todo',
@@ -861,7 +861,7 @@ describe('controller spec', () => {
         $ref: '#/components/schemas/MyModel',
       });
 
-      const globalSchemas = (spec.components ?? {}).schemas;
+      const globalSchemas = spec.components?.schemas;
       expect(globalSchemas).to.deepEqual({
         MyModel: {
           title: 'MyModel',
diff --git a/packages/repository-tests/src/helpers.repository-tests.ts b/packages/repository-tests/src/helpers.repository-tests.ts
index 4b6294c59a40..1c61fee68c9d 100644
--- a/packages/repository-tests/src/helpers.repository-tests.ts
+++ b/packages/repository-tests/src/helpers.repository-tests.ts
@@ -37,7 +37,7 @@ export function withCrudCtx(
  */
 export const deleteAllModelsInDefaultDataSource = withCrudCtx(ctx => {
   ctx.dataSource.deleteAllModels();
-});
+}) as Mocha.Func;
 
 /**
  * A union type between string and number to use since MongoDB and MySQL use
diff --git a/packages/rest-crud/src/crud-rest.controller.ts b/packages/rest-crud/src/crud-rest.controller.ts
index d299af479506..5033347bb052 100644
--- a/packages/rest-crud/src/crud-rest.controller.ts
+++ b/packages/rest-crud/src/crud-rest.controller.ts
@@ -280,7 +280,7 @@ function getIdSchema<T extends Entity>(
   const modelSchema = jsonToSchemaObject(
     getJsonSchema(modelCtor),
   ) as SchemaObject;
-  return (modelSchema.properties ?? {})[idProp] as SchemaObject;
+  return modelSchema.properties?.[idProp] as SchemaObject;
 }
 
 // Temporary implementation of a short-hand version of `@requestBody`