feat: add optional cookie jar support (#85)

If the `jar` field is set om the base service, the axios instance is wrapped in a library that adds cookie support. Values for `jar` can be an instance of cookie jar library or `true`, which will cause a default cookie jar to be created using the `tough-cookie` package.

Co-authored-by: Christian Compton <cbcompto@us.ibm.com>

README.md

@@ -79,6 +79,24 @@ The debug logger can be configured to be used for more than one library. In exam
 
 ``DEBUG=ibm-cloud-sdk-core:debug,other-lib:debug``
 
+## Cookie Jar Support
+By default, cookies are not supported in the SDK requests.  If your SDK would benefit from this functionality, simply edit your code to instantiate a cookie jar (or instruct your users to do so) and pass it in the object containing configuration options to the `BaseService` class, as shown below.
+
+```ts
+import tough = require('tough-cookie');
+
+class MyClass extends BaseService {
+  constructor(options: MyOptions) {
+    // pass the cookie jar object or simply pass the value `true`
+    // and a tough-cookie instance will be created by default
+    options.jar = new tough.CookieJar();
+    super(options);
+  }
+}
+```
+
+The example above uses [Tough Cookie](https://www.npmjs.com/package/tough-cookie) to provide these capabilities, but other cookie jar libraries can be used.
+
 ## Issues
 If you encounter an issue with this project, you are welcome to submit a [bug report](https://github.com/IBM/node-sdk-core/issues).
 Before opening a new issue, please search for similar issues. It's possible that someone has already reported it.

lib/base-service.ts

@@ -36,6 +36,8 @@ export interface UserOptions {
   version?: string;
   /** Set to `true` to allow unauthorized requests - not recommended for production use. */
   disableSslVerification?: boolean;
+  /** Set your own cookie jar object */
+  jar?: any;
   /** Deprecated. Use `serviceUrl` instead. */
   url?: string;
   /** Allow additional request config parameters */

lib/request-wrapper.ts

@@ -15,6 +15,7 @@
  */
 
 import axios from 'axios';
+import axiosCookieJarSupport from 'axios-cookiejar-support';
 import extend = require('extend');
 import FormData = require('form-data');
 import https = require('https');
@@ -27,7 +28,7 @@ const isBrowser = typeof window === 'object';
 const globalTransactionId = 'x-global-transaction-id';
 
 // Limit the type of axios configs to be customizable
-const allowedAxiosConfig = ['transformRequest', 'transformResponse', 'paramsSerializer', 'paramsSerializer', 'timeout', 'withCredentials', 'adapter', 'responseType', 'responseEncoding', 'xsrfCookieName', 'xsrfHeaderName', 'onUploadProgress', 'onDownloadProgress', 'maxContentLength', 'validateStatus', 'maxRedirects', 'socketPath', 'httpAgent', 'httpsAgent', 'proxy', 'cancelToken'];
+const allowedAxiosConfig = ['transformRequest', 'transformResponse', 'paramsSerializer', 'paramsSerializer', 'timeout', 'withCredentials', 'adapter', 'responseType', 'responseEncoding', 'xsrfCookieName', 'xsrfHeaderName', 'onUploadProgress', 'onDownloadProgress', 'maxContentLength', 'validateStatus', 'maxRedirects', 'socketPath', 'httpAgent', 'httpsAgent', 'proxy', 'cancelToken', 'jar'];
 
 export class RequestWrapper {
   private axiosInstance;
@@ -67,8 +68,16 @@ export class RequestWrapper {
 
     this.axiosInstance = axios.create(axiosConfig);
 
+    // if a cookie jar is provided, wrap the axios instance and update defaults
+    if (axiosOptions.jar) {
+      axiosCookieJarSupport(this.axiosInstance);
+
+      this.axiosInstance.defaults.withCredentials = true;
+      this.axiosInstance.defaults.jar = axiosOptions.jar;
+    }
+
     // set debug interceptors
-    if(process.env.NODE_DEBUG === 'axios' || process.env.DEBUG) {
+    if (process.env.NODE_DEBUG === 'axios' || process.env.DEBUG) {
       this.axiosInstance.interceptors.request.use(config => {
         logger.debug('Request:');
         try {

package.json

@@ -58,6 +58,7 @@
     "@types/jest": "^24.0.23",
     "@types/node": "~10.14.19",
     "axios": "^0.18.0",
+    "axios-cookiejar-support": "^0.5.1",
     "camelcase": "^5.3.1",
     "debug": "^4.1.1",
     "dotenv": "^6.2.0",

test/unit/base-service.test.js

@@ -120,6 +120,15 @@ describe('Base Service', () => {
     expect(testService.baseOptions.disableSslVerification).toBe(true);
   });
 
+  it('should store a cookie jar when set', () => {
+    const testService = new TestService({
+      authenticator: AUTHENTICATOR,
+      jar: true,
+    });
+
+    expect(testService.baseOptions.jar).toBe(true);
+  });
+
   it('should default disableSslVerification to false', () => {
     const testService = new TestService({
       authenticator: AUTHENTICATOR,

test/unit/cookiejar.test.js

@@ -0,0 +1,62 @@
+'use strict';
+
+// the `toBeInstanceOf` assertion compares for function reference equality
+// importing our own `tough-cookie` dependency would create a different function
+// reference and render the assertion unusable. the solution is to use the
+// dependency within axios-cookiejar-support
+const tough = require('axios-cookiejar-support/node_modules/tough-cookie');
+const { RequestWrapper } = require('../../dist/lib/request-wrapper');
+
+describe('cookie jar support', () => {
+  it('should not wrap the axios instance by default', () => {
+    const wrapper = new RequestWrapper();
+    expect(wrapper.axiosInstance.defaults.withCredentials).not.toBeDefined();
+    expect(wrapper.axiosInstance.interceptors.request.handlers.length).toBe(0);
+  });
+
+  it('passing a value for `jar` should produce interceptors and set flags', () => {
+    const wrapper = new RequestWrapper({ jar: true });
+    expect(wrapper.axiosInstance.defaults.withCredentials).toBe(true);
+    expect(wrapper.axiosInstance.interceptors.request.handlers.length).toBe(1);
+  });
+
+  it('given `true` for `jar`, the interceptors should create an instance of tough-cookie', () => {
+    const wrapper = new RequestWrapper({ jar: true });
+
+    expect(wrapper.axiosInstance.interceptors.request.handlers.length).toBe(1);
+    expect(wrapper.axiosInstance.interceptors.request.handlers[0].fulfilled).toBeInstanceOf(
+      Function
+    );
+
+    // should initially set the default to true
+    expect(wrapper.axiosInstance.defaults.jar).toBe(true);
+
+    // invoke the interceptor - it should be the one added by the cookie jar library
+    // it should see that `jar` is `true` and create a default instance of tough.CookieJar
+    // this would noramlly happen just before a request is sent
+    wrapper.axiosInstance.interceptors.request.handlers[0].fulfilled(
+      wrapper.axiosInstance.defaults
+    );
+
+    expect(wrapper.axiosInstance.defaults.jar).toBeInstanceOf(tough.CookieJar);
+  });
+
+  it('given arbitrary value for `jar`, the interceptor should use it as cookie jar', () => {
+    // the axios-cookiejar-support interceptor requires the jar object
+    // to have the method `getCookieString`
+    const mockCookieJar = { getCookieString: () => 'mock-string' };
+    const wrapper = new RequestWrapper({ jar: mockCookieJar });
+
+    // should still set interceptors and withCredentials flag
+    expect(wrapper.axiosInstance.interceptors.request.handlers.length).toBe(1);
+    expect(wrapper.axiosInstance.defaults.withCredentials).toBe(true);
+    expect(wrapper.axiosInstance.defaults.jar).toEqual(mockCookieJar);
+
+    // invoke the interceptor, the default jar should remain the same
+    wrapper.axiosInstance.interceptors.request.handlers[0].fulfilled(
+      wrapper.axiosInstance.defaults
+    );
+
+    expect(wrapper.axiosInstance.defaults.jar).toEqual(mockCookieJar);
+  });
+});