Adds "ctx.cookie()" response transformer

package.json

@@ -31,6 +31,7 @@
   "dependencies": {
     "@open-draft/until": "^1.0.0",
     "chalk": "^3.0.0",
+    "cookie": "^0.4.0",
     "graphql": "^14.6.0",
     "node-match-path": "^0.3.1",
     "ramda": "^0.27.0",
@@ -40,6 +41,7 @@
   "devDependencies": {
     "@babel/core": "^7.9.0",
     "@babel/preset-env": "^7.9.0",
+    "@types/cookie": "^0.3.3",
     "@types/jest": "^25.1.2",
     "@types/node": "^13.7.7",
     "@types/puppeteer": "^2.0.1",

src/context/cookie.test.ts

@@ -0,0 +1,24 @@
+import cookieUtils from 'cookie'
+import { cookie } from './cookie'
+import { response } from '../response'
+
+describe('cookie', () => {
+  describe('given I set a cookie', () => {
+    let result: ReturnType<typeof response>
+
+    beforeAll(() => {
+      result = response(cookie('my-cookie', 'arbitrary-value'))
+    })
+
+    it('should be set on the response headers', () => {
+      expect(result.headers.get('set-cookie')).toEqual(
+        'my-cookie=arbitrary-value',
+      )
+    })
+
+    it('should set the cookie on "document.cookie"', () => {
+      const allCookies = cookieUtils.parse(document.cookie)
+      expect(allCookies).toHaveProperty('my-cookie', 'arbitrary-value')
+    })
+  })
+})

src/context/cookie.ts

@@ -0,0 +1,20 @@
+import cookieUtils, { CookieSerializeOptions } from 'cookie'
+import { ResponseTransformer } from '../response'
+
+/**
+ * Sets a given cookie on the response.
+ * @example
+ * res(cookie('name', 'value'))
+ */
+export const cookie = (
+  name: string,
+  value: string,
+  options?: CookieSerializeOptions,
+): ResponseTransformer => {
+  return (res) => {
+    const serializedCookie = cookieUtils.serialize(name, value, options)
+    res.headers.set('Set-Cookie', serializedCookie)
+    document.cookie = serializedCookie
+    return res
+  }
+}

src/context/index.ts

@@ -1,10 +1,11 @@
+export { status } from './status'
+export { set } from './set'
+export { cookie } from './cookie'
 export { body } from './body'
 export { data } from './data'
 export { delay } from './delay'
 export { errors } from './errors'
 export { fetch } from './fetch'
 export { json } from './json'
-export { set } from './set'
-export { status } from './status'
 export { text } from './text'
 export { xml } from './xml'

src/handlers/rest.ts

@@ -3,6 +3,7 @@ import { RequestHandler, ResponseResolver } from './requestHandler'
 import { Mask } from '../composeMocks'
 import { set } from '../context/set'
 import { status } from '../context/status'
+import { cookie } from '../context/cookie'
 import { body } from '../context/body'
 import { text } from '../context/text'
 import { json } from '../context/json'
@@ -23,6 +24,7 @@ export enum RESTMethods {
 export const restContext = {
   set,
   status,
+  cookie,
   body,
   text,
   json,

test/rest-api/cookies.mocks.ts

@@ -0,0 +1,14 @@
+import { composeMocks, rest } from 'msw'
+
+const { start } = composeMocks(
+  rest.get('/user', (req, res, ctx) => {
+    return res(
+      ctx.cookie('my-cookie', 'value'),
+      ctx.json({
+        mocked: true,
+      }),
+    )
+  }),
+)
+
+start()

test/rest-api/cookies.test.ts

@@ -0,0 +1,51 @@
+import * as path from 'path'
+import * as cookieUtils from 'cookie'
+import { Response } from 'puppeteer'
+import { TestAPI, runBrowserWith } from '../support/runBrowserWith'
+
+describe('REST: Cookies', () => {
+  let test: TestAPI
+
+  beforeAll(async () => {
+    test = await runBrowserWith(path.resolve(__dirname, 'cookies.mocks.ts'))
+  })
+
+  afterAll(() => {
+    return test.cleanup()
+  })
+
+  describe('given I set cookies on the mocked response', () => {
+    let res: Response
+
+    beforeAll(async () => {
+      res = await test.request({
+        url: `${test.origin}/user`,
+      })
+    })
+
+    it('should return the mocked response', async () => {
+      const headers = res.headers()
+      const body = await res.json()
+
+      expect(headers).toHaveProperty('x-powered-by', 'msw')
+      expect(body).toEqual({
+        mocked: true,
+      })
+    })
+
+    it('should not have "Set-Cookie" header on the mocked response', () => {
+      const headers = res.headers()
+
+      expect(headers).not.toHaveProperty('set-cookie')
+    })
+
+    it('should be able to access response cookies via "document.cookie"', async () => {
+      const cookieString = await test.page.evaluate(() => {
+        return document.cookie
+      })
+      const allCookies = cookieUtils.parse(cookieString)
+
+      expect(allCookies).toHaveProperty('my-cookie', 'value')
+    })
+  })
+})

yarn.lock

@@ -1012,6 +1012,11 @@
   dependencies:
     "@types/node" "*"
 
+"@types/cookie@^0.3.3":
+  version "0.3.3"
+  resolved "https://registry.yarnpkg.com/@types/cookie/-/cookie-0.3.3.tgz#85bc74ba782fb7aa3a514d11767832b0e3bc6803"
+  integrity sha512-LKVP3cgXBT9RYj+t+9FDKwS5tdI+rPBXaNSkma7hvqy35lc7mAokC2zsqWJH0LaqIt3B962nuYI77hsJoT1gow==
+
 "@types/events@*":
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/@types/events/-/events-3.0.0.tgz#2862f3f58a9a7f7c3e78d79f130dd4d71c25c2a7"
@@ -2522,7 +2527,7 @@ cookie-signature@1.0.6:
   resolved "https://registry.yarnpkg.com/cookie-signature/-/cookie-signature-1.0.6.tgz#e303a882b342cc3ee8ca513a79999734dab3ae2c"
   integrity sha1-4wOogrNCzD7oylE6eZmXNNqzriw=
 
-cookie@0.4.0:
+cookie@0.4.0, cookie@^0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/cookie/-/cookie-0.4.0.tgz#beb437e7022b3b6d49019d088665303ebe9c14ba"
   integrity sha512-+Hp8fLp57wnUSt0tY0tHEXh4voZRDnoIrZPqlo3DPiI4y9lwg/jqx+1Om94/W6ZaPDOUbnjOt/99w66zk+l1Xg==