diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NodeJSExpressServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NodeJSExpressServerCodegen.java
index d89fb863fa8e..4efb64e61d18 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NodeJSExpressServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/NodeJSExpressServerCodegen.java
@@ -93,7 +93,6 @@ public NodeJSExpressServerCodegen() {
         supportingFiles.add(new SupportingFile("utils" + File.separator + "writer.mustache", "utils", "writer.js"));
 
         // controllers folder
-        supportingFiles.add(new SupportingFile("controllers" + File.separator + "test.mustache", "controllers", "TestController.js"));
         supportingFiles.add(new SupportingFile("controllers" + File.separator + "index.mustache", "controllers", "index.js"));
         supportingFiles.add(new SupportingFile("controllers" + File.separator + "Controller.mustache", "controllers", "Controller.js"));
         // service folder
diff --git a/samples/server/petstore/nodejs-express-server/api/openapi.yaml b/samples/server/petstore/nodejs-express-server/api/openapi.yaml
index 401e628f3bd1..1f42f2aa3f88 100644
--- a/samples/server/petstore/nodejs-express-server/api/openapi.yaml
+++ b/samples/server/petstore/nodejs-express-server/api/openapi.yaml
@@ -8,7 +8,15 @@ info:
   title: OpenAPI Petstore
   version: 1.0.0
 servers:
-- url: http://petstore.swagger.io/v2
+- url: http://localhost:{port}/api/{basePath}
+  variables:
+    port:
+      enum:
+        - '3000'
+        - '3009'
+      default: '3000'
+    basePath:
+      default: 'v2'
 tags:
 - description: Everything about your Pets
   name: pet
diff --git a/samples/server/petstore/nodejs-express-server/controllers/TestController.js b/samples/server/petstore/nodejs-express-server/controllers/TestController.js
deleted file mode 100644
index 516c135b45be..000000000000
--- a/samples/server/petstore/nodejs-express-server/controllers/TestController.js
+++ /dev/null
@@ -1,72 +0,0 @@
-const Service = require('../services/Service');
-
-const testItems = require('../tests/testFiles/testItems.json');
-
-class TestService {
-  static testGetController() {
-    return new Promise(
-      async (resolve, reject) => {
-        try {
-          resolve(Service.successResponse(
-            testItems,
-            200,
-          ));
-        } catch (e) {
-          const message = e.getMessage() || 'Could not get items. Server error';
-          reject(Service.rejectResponse(message, 500));
-        }
-      },
-    );
-
-  sendResponse(request, response) {
-    response.status(200);
-    const objectToReturn = {};
-    Object.keys(request.swagger.paramValues).forEach((key) => {
-      const val = request.swagger.paramValues[key];
-      if (val instanceof Object) {
-        objectToReturn[key] = val.originalname || val.name || val;
-      } else {
-        objectToReturn[key] = request.swagger.paramValues[key];
-      }
-    });
-    response.json(objectToReturn);
-  }
-
-  confirmRouteGetSingle(request, response) {
-    this.sendResponse(request, response);
-  }
-
-  confirmRouteGetMany(request, response) {
-    this.sendResponse(request, response);
-  }
-
-  confirmRoutePost(request, response) {
-    this.sendResponse(request, response);
-  }
-
-  confirmRoutePut(request, response) {
-    this.sendResponse(request, response);
-  }
-
-  async testGetController(request, response) {
-    await Controller.handleRequest(request, response, this.service.testGetController);
-  }
-
-  async testPostController(request, response) {
-    await Controller.handleRequest(request, response, this.service.testPostController);
-  }
-
-  async testPutController(request, response) {
-    await Controller.handleRequest(request, response, this.service.testPutController);
-  }
-
-  async testDeleteController(request, response) {
-    await Controller.handleRequest(request, response, this.service.testDeleteController);
-  }
-
-  async testFindByIdController(request, response) {
-    await Controller.handleRequest(request, response, this.service.testFindByIdController);
-  }
-}
-
-module.exports = TestController;
diff --git a/samples/server/petstore/nodejs-express-server/controllers/index.js b/samples/server/petstore/nodejs-express-server/controllers/index.js
index 3dc796c1e507..0ad912de2051 100644
--- a/samples/server/petstore/nodejs-express-server/controllers/index.js
+++ b/samples/server/petstore/nodejs-express-server/controllers/index.js
@@ -1,11 +1,9 @@
 const PetController = require('./PetController');
 const StoreController = require('./StoreController');
 const UserController = require('./UserController');
-const TestController = require('./TestController');
 
 module.exports = {
   PetController,
   StoreController,
   UserController,
-  TestController,
 };
diff --git a/samples/server/petstore/nodejs-express-server/models/Category.js b/samples/server/petstore/nodejs-express-server/models/Category.js
new file mode 100644
index 000000000000..01d408c7512a
--- /dev/null
+++ b/samples/server/petstore/nodejs-express-server/models/Category.js
@@ -0,0 +1,21 @@
+const ono = require('ono');
+const Model = require('./Model');
+
+class Category {
+  constructor(name, id) {
+    const validationErrors = (Model.validateModel(Category, {name, id}));
+    if (validationErrors.length === 0) {
+      this.id = id;
+      this.name = name;
+    } else {
+      throw ono('Tried to create an invalid Category instance', {errors: validationErrors});
+    }
+  }
+}
+
+Category.types = {
+  id: 'integer',
+  name: 'string',
+};
+
+module.exports = Category;
diff --git a/samples/server/petstore/nodejs-express-server/models/Model.js b/samples/server/petstore/nodejs-express-server/models/Model.js
new file mode 100644
index 000000000000..d60aabb4ece5
--- /dev/null
+++ b/samples/server/petstore/nodejs-express-server/models/Model.js
@@ -0,0 +1,47 @@
+class Model {
+  static validateModel(modelClass, variables) {
+    const invalidArray = [];
+    Object.entries(variables).forEach(([key, value]) => {
+      const typeToCheck = modelClass.types[key];
+      switch (typeToCheck) {
+        case 'string':
+          if (!(typeof value === 'string' || value instanceof String)) {
+            invalidArray.push({ key, expectedType: typeToCheck, value });
+          }
+          break;
+        case 'number':
+        case 'integer':
+          if (!(typeof value === 'number' && !Number.isNaN(value))) {
+            invalidArray.push({ key, expectedType: typeToCheck, value });
+          }
+          break;
+        case 'array':
+          if (!(value && typeof value === 'object' && value.constructor === Array)) {
+            invalidArray.push({ key, expectedType: typeToCheck, value });
+          }
+          break;
+        case 'object':
+          if (!(value && typeof value === 'object' && value.constructor === Array)) {
+            invalidArray.push({ key, expectedType: typeToCheck, value });
+          }
+          break;
+        case 'boolean':
+          if (!(typeof value === 'boolean')) {
+            invalidArray.push({ key, expectedType: typeToCheck, value });
+          }
+          break;
+        default:
+          break;
+      }
+    });
+    modelClass.required.forEach((requiredFieldName) => {
+      if (variables[requiredFieldName] === undefined || variables[requiredFieldName] === '') {
+        invalidArray.push(
+          { field: requiredFieldName, required: true, value: variables[requiredFieldName] },
+        );
+      }
+    });
+    return invalidArray;
+  }
+}
+module.exports = Model;
diff --git a/samples/server/petstore/nodejs-express-server/models/Pet.js b/samples/server/petstore/nodejs-express-server/models/Pet.js
new file mode 100644
index 000000000000..cecf677196aa
--- /dev/null
+++ b/samples/server/petstore/nodejs-express-server/models/Pet.js
@@ -0,0 +1,35 @@
+const ono = require('ono');
+const Model = require('./Model');
+const Tag = require('./Tag');
+const Category = require('./Category');
+
+class Pet {
+  constructor(photoUrls, name, id, tags, status, category) {
+    const validationErrors = Model.validateModel(Pet, {
+      photoUrls, name, id, tags, status, category,
+    });
+    if (validationErrors.length === 0) {
+      this.photoUrls = photoUrls;
+      this.name = name;
+      this.id = id;
+      this.tags = tags.map(t => new Tag(...t));
+      this.status = status;
+      this.category = new Category(category);
+    } else {
+      throw ono('Tried to create an invalid Pet instance', { errors: validationErrors });
+    }
+  }
+}
+
+Pet.types = {
+  photoUrls: 'array',
+  name: 'string',
+  id: 'string',
+  tags: 'array',
+  status: 'string',
+  category: 'object',
+};
+
+Pet.required = ['name', 'photoUrls'];
+
+module.exports = Pet;
diff --git a/samples/server/petstore/nodejs-express-server/models/Tag.js b/samples/server/petstore/nodejs-express-server/models/Tag.js
new file mode 100644
index 000000000000..64f2c3e78deb
--- /dev/null
+++ b/samples/server/petstore/nodejs-express-server/models/Tag.js
@@ -0,0 +1,17 @@
+const ono = require('ono');
+const Model = require('./Model');
+
+class Tag {
+  constructor(name, id) {
+    const validationErrors = Model.validateModel(Tag,
+      { name, id });
+    if (validationErrors.length === 0) {
+      this.name = name;
+      this.id = id;
+    } else {
+      throw ono('Tried to create an invalid Tag instance', { errors: validationErrors });
+    }
+  }
+}
+
+module.exports = Tag;
diff --git a/samples/server/petstore/nodejs-express-server/models/index.js b/samples/server/petstore/nodejs-express-server/models/index.js
new file mode 100644
index 000000000000..66963054a241
--- /dev/null
+++ b/samples/server/petstore/nodejs-express-server/models/index.js
@@ -0,0 +1,9 @@
+const CategoryModel = require('./Category');
+const PetModel = require('./Pet');
+const TagModel = require('./Tag');
+
+module.exports = {
+  CategoryModel,
+  PetModel,
+  TagModel,
+};
diff --git a/samples/server/petstore/nodejs-express-server/package.json b/samples/server/petstore/nodejs-express-server/package.json
index 18e7d92069f9..ed38f18c8d3e 100644
--- a/samples/server/petstore/nodejs-express-server/package.json
+++ b/samples/server/petstore/nodejs-express-server/package.json
@@ -8,7 +8,8 @@
     "start": "node index.js"
   },
   "keywords": [
-    "openapi-generator", "openapi"
+    "openapi-generator",
+    "openapi"
   ],
   "license": "Unlicense",
   "private": true,
@@ -20,6 +21,9 @@
     "express": "^4.16.4",
     "express-openapi-validator": "^1.0.0",
     "js-yaml": "^3.3.0",
+    "jstoxml": "^1.5.0",
+    "ono": "^5.0.1",
+    "openapi-sampler": "^1.0.0-beta.15",
     "swagger-express-middleware": "^2.0.2",
     "swagger-tools": "^0.10.4",
     "swagger-ui-express": "^4.0.2",
@@ -35,5 +39,10 @@
     "eslint-plugin-import": "^2.17.2",
     "form-data": "^2.3.3",
     "mocha": "^6.1.4"
+  },
+  "eslintConfig": {
+    "env": {
+      "node": true
+    }
   }
 }
diff --git a/samples/server/petstore/nodejs-express-server/tests/SwaggerRouterTests.js b/samples/server/petstore/nodejs-express-server/tests/SwaggerRouterTests.js
deleted file mode 100644
index efe39ae5ffb9..000000000000
--- a/samples/server/petstore/nodejs-express-server/tests/SwaggerRouterTests.js
+++ /dev/null
@@ -1,164 +0,0 @@
-const path = require('path');
-const fs = require('fs');
-const { AssertionError } = require('assert');
-const {
-  describe, before, after, it,
-} = require('mocha');
-const chai = require('chai');
-const chaiAsPromised = require('chai-as-promised');
-const { get, post, put } = require('axios');
-const FormData = require('form-data');
-
-const logger = require('./logger');
-const config = require('./config');
-const App = require('../app');
-
-// IMPORTANT CHANGE: WORKING ON TEST SWAGGER FILE
-
-config.OPENAPI_YAML = path.join(__dirname, 'testFiles', 'swagger.yaml');
-
-const app = new App(config);
-chai.use(chaiAsPromised);
-chai.should();
-
-describe('Tests for confirming that the Swagger router works as expected', () => {
-  const pathVarValue = 123;
-  const urlPath = `${config.FULL_PATH}/test/${pathVarValue}?queryOptionalNumber=2&queryRequiredString=sss`;
-  const headerRequiredArray = [1, 2, 3];
-  before(async () => {
-    try {
-      await app.launch();
-      logger.info('express server launched\n');
-    } catch (error) {
-      logger.info(error);
-      await app.close();
-      throw (error);
-    }
-  });
-
-  after(async () => {
-    await app.close()
-      .catch(error => logger.error(error));
-    logger.error('express server closed');
-  });
-
-  it('Should handle variables sent in the header',
-    async () => {
-      try {
-        const headerOptionalBool = false;
-        const headers = { headerOptionalBool, headerRequiredArray };
-        const allHeadersResponse = await get(urlPath, { headers });
-        allHeadersResponse.status.should.equal(200, 'Expecting a successful allHeadersResponse');
-        allHeadersResponse.data.should.have.property('headerOptionalBool').and.equal(headerOptionalBool);
-        allHeadersResponse.data.should.have.property('headerRequiredArray');
-        allHeadersResponse.data.headerRequiredArray
-          .should.have.deep.members(headerRequiredArray);
-        const onlyRequiredResponse = await get(urlPath, { headers: { headerRequiredArray } });
-        onlyRequiredResponse.status.should.equal(200, 'Expecting a successful onlyRequiredResponse');
-        onlyRequiredResponse.data.should.have.property('headerOptionalBool').and.equal(headerOptionalBool);
-        onlyRequiredResponse.data.should.have.property('headerRequiredArray');
-        onlyRequiredResponse.data.headerRequiredArray.should.have.deep.members(headerRequiredArray);
-        await get(urlPath, { headers: { headerOptionalBool } })
-          .catch((error => error.response.status.should.equal(400)));
-      } catch (error) {
-        if (error.response && error.response.data) {
-          logger.error(JSON.stringify(error.response.data));
-        } else {
-          logger.error(error);
-        }
-        error.should.have.property('response');
-        throw new Error(error);
-      }
-    });
-
-  it('Should handle variables sent in the path',
-    async () => {
-      try {
-        const headers = { headerRequiredArray };
-        const correctPathVarResponse = await get(urlPath, { headers });
-        correctPathVarResponse.status.should.equal(200);
-        correctPathVarResponse.data.should.have.property('pathRequiredNumber').and.equal(pathVarValue);
-        const pathVarNotInt = `${config.FULL_PATH}/test/aaa?queryOptionalNumber=2&queryRequiredString=sss`;
-        await get(pathVarNotInt, { headers: { headers } })
-          .catch((error => error.response.status.should.equal(400)));
-      } catch (error) {
-        logger.error(error);
-        error.should.have.property('response');
-        throw new Error(error);
-      }
-    });
-
-  it('Should handle variables sent in the queryString',
-    async () => {
-      try {
-        const headers = { headerRequiredArray };
-        // const allHeadersResponse = await get(urlPath, { headers });
-        const queryRequiredString = 'sss';
-        const noOptionalQueryUrl = `${config.FULL_PATH}/test/${pathVarValue}/?queryRequiredString=${queryRequiredString}`;
-        const noOptionalQueryResponse = await get(noOptionalQueryUrl, { headers });
-        noOptionalQueryResponse.status.should.equal(200, 'Expecting a successful allHeadersResponse');
-        noOptionalQueryResponse.data.should.have.property('queryRequiredString').and.equal(queryRequiredString);
-        noOptionalQueryResponse.data.should.have.property('queryOptionalNumber').and.equal(1);
-
-        const noRequiredQueryUrl = `${config.FULL_PATH}/test/${pathVarValue}`;
-        await get(noRequiredQueryUrl, headers)
-          .catch((error => error.response.status.should.equal(400)));
-      } catch (error) {
-        logger.error(error);
-        error.should.have.property('response');
-        throw new Error(error);
-      }
-    });
-
-  it('Should handle variables sent in the body',
-    async () => {
-      try {
-        const fullPathURL = `${config.FULL_PATH}/test/`;
-        const body = { firstName: 'Foo', lastName: 'Bar' };
-        const fullBodyResponse = await post(fullPathURL, body,
-          { headers: { headerRequiredArray } });
-        fullBodyResponse.status.should.equal(200);
-        await post(fullPathURL, { firstName: 'foo' },
-          { headers: { headerRequiredArray } })
-          .then(response => response.status.should.equal(200));
-        await post(fullPathURL, { lastName: 'bar' },
-          { headers: { headerRequiredArray } })
-          .catch(error => error.response.status.should.equal(400));
-      } catch (error) {
-        error.should.have.property('response');
-        console.error(JSON.stringify(error.response.data));
-      }
-    });
-
-  it('Should handle variables sent in the formData',
-    async () => {
-      try {
-        const fullPathURL = `${config.FULL_PATH}/test/123`;
-        const formData = new FormData();
-        const person = {
-          firstName: 'Foo',
-          lastName: 'Bar',
-          image: fs.createReadStream(path.join(__dirname, 'testFiles', 'pet.json')),
-        };
-        Object.keys(person).forEach(key => formData.append(key, person[key]));
-        const formResponse = await put(fullPathURL, formData,
-          {
-            headers: formData.getHeaders(),
-          });
-        formResponse.status.should.equal(200);
-        Object.keys(person).forEach((nameKey) => {
-          formResponse.data.should.have.property(nameKey);
-          if (person[nameKey] instanceof String) {
-            formResponse.data[nameKey].should.equal(person[nameKey]);
-          }
-        });
-      } catch (error) {
-        if (error instanceof AssertionError) {
-          throw error;
-        }
-        error.should.have.property('response');
-        console.error(JSON.stringify(error.response.data));
-        throw new Error(error);
-      }
-    });
-});
diff --git a/samples/server/petstore/nodejs-express-server/tests/routingTests.js b/samples/server/petstore/nodejs-express-server/tests/routingTests.js
new file mode 100644
index 000000000000..7018c8fc5a86
--- /dev/null
+++ b/samples/server/petstore/nodejs-express-server/tests/routingTests.js
@@ -0,0 +1,147 @@
+/**
+ * The purpose of these tests is to confirm that every path in the openapi spec, if built properly,
+ * returns a valid 200, with a simple text response.
+ * The codeGen will generate a response string including the name of the operation that was called.
+ * These tests confirm that the codeGen worked as expected.
+ * Once we start adding our own business logic, these
+ * tests will fail. It is recommended to keep these tests updated with the code changes.
+ */
+const {
+  describe, before, after, it,
+} = require('mocha');
+const assert = require('assert').strict;
+const chai = require('chai');
+const chaiAsPromised = require('chai-as-promised');
+const axios = require('axios');
+const yamljs = require('yamljs');
+const openApiSampler = require('openapi-sampler');
+const jstoxml = require('jstoxml');
+const logger = require('./logger');
+const config = require('./config');
+const App = require('../app');
+
+const app = new App(config);
+chai.use(chaiAsPromised);
+chai.should();
+
+
+const pathPrefix = `${config.URL_PATH}:${config.URL_PORT}/api/v2`;
+const spec = yamljs.load(config.OPENAPI_YAML);
+
+const parseParameters = (originalPath, schemaParameters) => {
+  let path = originalPath;
+  const headers = {};
+  const queryParams = [];
+  schemaParameters.forEach((parameter) => {
+    const parameterValue = parameter.example || openApiSampler.sample(parameter.schema);
+    switch (parameter.in) {
+      case 'header':
+        headers[parameter.name] = parameterValue;
+        break;
+      case 'path':
+        path = path.replace(`{${parameter.name}}`, parameterValue);
+        break;
+      case 'query':
+        queryParams.push(`${parameter.name}=${parameterValue}`);
+        break;
+      default:
+        break;
+    }
+  });
+  return { path, headers, queryString: queryParams.join('&') };
+};
+
+const buildRequestObject = (pathEndpoint, method, operationObject, requestsArray) => {
+  logger.info(`method: ${method}`);
+  let headers = {};
+  let requestBody = {};
+  let queryString = '';
+  let path = pathEndpoint;
+  if (operationObject.parameters !== undefined) {
+    logger.info('this is a request with parameters');
+    ({ path, headers, queryString } = parseParameters(pathEndpoint, operationObject.parameters));
+    if (queryString.length > 0) {
+      path += `?${queryString}`;
+    }
+    Object.entries(headers).forEach(([headerName, headerValue]) => {
+      headers[headerName] = headerValue;
+    });
+  }
+  if (operationObject.requestBody !== undefined) {
+    logger.info('This is a request with a body');
+    const content = Object.entries(operationObject.requestBody.content);
+    content.forEach(([contentType, contentObject]) => {
+      requestBody = openApiSampler.sample(contentObject.schema, {}, spec);
+      let requestXML;
+      if (contentType === 'application/xml') {
+        requestXML = jstoxml.toXML(requestBody);
+      }
+      headers['Content-Type'] = contentType;
+      requestsArray.push({
+        method,
+        path,
+        body: requestXML || requestBody,
+        headers,
+      });
+    });
+  } else {
+    requestsArray.push({
+      method,
+      path,
+      headers,
+    });
+  }
+};
+
+const getApiRequestsData = (apiSchema) => {
+  const requestsArray = [];
+  Object.entries(apiSchema.paths).forEach(([pathEndpoint, pathObject]) => {
+    logger.info(`adding path: ${pathPrefix}${pathEndpoint} to testing array`);
+    Object.entries(pathObject).forEach(([operationMethod, operationObject]) => {
+      buildRequestObject(pathEndpoint, operationMethod, operationObject, requestsArray);
+    });
+  });
+  return requestsArray;
+};
+
+describe('API tests, checking that the codegen generated code that allows all paths specified in schema to work', () => {
+  before(async () => {
+    try {
+      await app.launch();
+      logger.info('express server launched\n');
+    } catch (error) {
+      logger.info(error);
+      await app.close();
+      throw (error);
+    }
+  });
+
+  after(async () => {
+    await app.close()
+      .catch(error => logger.error(error));
+    logger.error('express server closed');
+  });
+
+  const requestsArray = getApiRequestsData(spec);
+  requestsArray.forEach((requestObject) => {
+    it(`should run ${requestObject.method.toUpperCase()} request to ${requestObject.path} and return healthy 200`, async () => {
+      try {
+        const {
+          method, path, body, headers,
+        } = requestObject;
+        const url = `${pathPrefix}${path}`;
+        logger.info(`testing ${method.toUpperCase()} call to ${url}. encoding: ${headers['Content-Type']}`);
+        const response = await axios({
+          method,
+          url,
+          data: body,
+          headers,
+        });
+        response.should.have.property('status');
+        response.status.should.equal(200);
+      } catch (e) {
+        assert.fail(e.message);
+      }
+    });
+  });
+});