Implement support for cookies with JSON values

src/Request.ts

@@ -50,7 +50,7 @@ export default class Request {
     * Contains cookies sent by the request (key/value pairs). If the request contains no
     * cookies, it defaults to `{}`.
     */
-   public readonly cookies: StringMap;
+   public readonly cookies: { [key: string]: any };
 
    /**
     * Contains the hostname derived from the `Host` HTTP header.
@@ -358,7 +358,19 @@ export default class Request {
          return {};
       }
 
-      return cookie.parse(cookieHeader);
+      const cookies = cookie.parse(cookieHeader);
+
+      _.each(cookies, (v, k): void => {
+         if (_.isString(v) && v.substring(0, 2) === 'j:') {
+            try {
+               cookies[k] = JSON.parse(v.substring(2));
+            } catch(e) {
+               // no-op
+            }
+         }
+      });
+
+      return cookies;
    }
 
    private _parseHostname(): string | undefined {

src/Response.ts

@@ -219,13 +219,21 @@ export default class Response {
     * Sets cookie `name` to `value`, optionally with the specified cookie options. See
     * `CookieOpts`.
     *
+    * Generally cookie values are strings, but you can also supply a JS object, which will
+    * be stringified with `JSON.stringify(userVal)` and prefixed with `j:`. This matches
+    * what Express does with response cookies and what their cookie parser middleware does
+    * with incoming (request) cookie headers.
+    *
+    * @see https://github.com/expressjs/cookie-parser/blob/1dc306b0ebe86ab98521811cc090740b4bef48e7/index.js#L84-L86
+    * @see https://github.com/expressjs/express/blob/dc538f6e810bd462c98ee7e6aae24c64d4b1da93/lib/response.js#L836-L838
+    *
     * TODO: how does a user see the documentation for `CookieOpts`?
     *
     * @param name the name of the cookie
     * @param userVal the value of the cookie
     * @param userOpts the options (such as domain, path, etc)
     */
-   public cookie(name: string, userVal: string, userOpts?: CookieOpts): Response {
+   public cookie(name: string, userVal: any, userOpts?: CookieOpts): Response {
       const opts = _.extend({ path: '/' }, userOpts) as CookieOpts,
             value = (_.isObject(userVal) ? `j:${JSON.stringify(userVal)}` : String(userVal));
 

tests/Request.test.ts

@@ -116,6 +116,9 @@ describe('Request', () => {
          _.each(allRequestTypes, (req) => {
             expect(req.cookies.uid).to.eql('abc');
             expect(req.cookies.baz).to.eql('foo[a]');
+            expect(req.cookies.obj).to.eql({ abc: 123 });
+            expect(req.cookies.onechar).to.eql('j');
+            expect(req.cookies.bad).to.eql('j:{a}');
          });
       });
 

tests/Response.test.ts

@@ -280,7 +280,7 @@ describe('Request', () => {
    });
 
    describe('cookie', () => {
-      const test = (name: string, val: string, opts: CookieOpts | undefined, expectedHeader: string): void => {
+      const test = (name: string, val: any, opts: CookieOpts | undefined, expectedHeader: string): void => {
          it(`sets cookie headers correctly - ${expectedHeader}`, () => {
             expect(sampleResp.getHeaders()).to.eql({});
             sampleResp.cookie(name, val, opts);
@@ -294,6 +294,10 @@ describe('Request', () => {
       test('foo', 'bar', { path: '/', httpOnly: true }, 'foo=bar; Path=/; HttpOnly');
       test('foo', 'url encoded', { path: '/', httpOnly: true }, 'foo=url%20encoded; Path=/; HttpOnly');
       test('foo', 'bar baz', { secure: true, domain: 'example.com' }, 'foo=bar%20baz; Domain=example.com; Path=/; Secure');
+      test('foo', { abc: 123 }, undefined, `foo=${encodeURIComponent('j:{"abc":123}')}; Path=/`);
+      test('foo', { abc: 123 }, { path: '/foo', httpOnly: true }, `foo=${encodeURIComponent('j:{"abc":123}')}; Path=/foo; HttpOnly`);
+      test('foo', [ 'a', 'b' ], undefined, `foo=${encodeURIComponent('j:["a","b"]')}; Path=/`);
+      test('foo', [ 'a', 'b' ], { path: '/foo', httpOnly: true }, `foo=${encodeURIComponent('j:["a","b"]')}; Path=/foo; HttpOnly`);
 
       const encoder = (v: string): string => { return v.toUpperCase(); };
 

tests/samples.ts

@@ -80,7 +80,7 @@ export const apiGatewayRequest = (): APIGatewayRequestEvent => {
          'X-Forwarded-Port': '443',
          'X-Forwarded-Proto': 'https',
          Referer: 'https://en.wikipedia.org/wiki/HTTP_referer',
-         Cookie: 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D',
+         Cookie: 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D; obj=j%3A%7B%22abc%22%3A123%7D; onechar=j; bad=j%3A%7Ba%7D',
       },
       multiValueHeaders: {
          Accept: [ '*/*' ],
@@ -100,7 +100,7 @@ export const apiGatewayRequest = (): APIGatewayRequestEvent => {
          'X-Forwarded-Port': [ '443' ],
          'X-Forwarded-Proto': [ 'https' ],
          Referer: [ 'https://en.wikipedia.org/wiki/HTTP_referer' ],
-         Cookie: [ 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D' ],
+         Cookie: [ 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D; obj=j%3A%7B%22abc%22%3A123%7D; onechar=j; bad=j%3A%7Ba%7D' ],
       },
       queryStringParameters: {
          'foo[a]': 'bar b',
@@ -151,7 +151,7 @@ export const albRequest = (): ApplicationLoadBalancerRequestEvent => {
          'x-forwarded-proto': 'http',
          // Using "referer" (one "r") on this request, and "referrer" (two) below
          referer: 'https://en.wikipedia.org/wiki/HTTP_referer',
-         cookie: 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D',
+         cookie: 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D; obj=j%3A%7B%22abc%22%3A123%7D; onechar=j; bad=j%3A%7Ba%7D',
       },
    });
 };
@@ -174,7 +174,7 @@ export const albMultiValHeadersRequest = (): ApplicationLoadBalancerRequestEvent
          'x-forwarded-proto': [ 'http' ],
          // Using "referrer" (two "r"s) on this request, and "referer" (one) above
          referrer: [ 'https://en.wikipedia.org/wiki/HTTP_referer' ],
-         cookie: [ 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D' ],
+         cookie: [ 'uid=abc; ga=1234; foo=bar; baz=foo%5Ba%5D; obj=j%3A%7B%22abc%22%3A123%7D; onechar=j; bad=j%3A%7Ba%7D' ],
       },
    });
 };