feat: add cors middleware

Author: antongolub

README.md

@@ -8,9 +8,10 @@ npm i @qiwi/mware
 ```
 
 ### Middlewares
-* [mware-mdc](../mware-mdc/README.md)
-* [mware-logger](../mware-logger/README.md)
-* [mware-crumbs](../mware-crumbs/README.md)
+* [mware-mdc](./packages/mware-mdc/README.md)
+* [mware-logger](./packages/mware-logger/README.md)
+* [mware-crumbs](./packages/mware-crumbs/README.md)
+* [mware-cors](./packages/mware-cors/README.md)
 
 ### Usage
 ```javascript

packages/mware-cors/.babelrc

@@ -0,0 +1,35 @@
+{
+  "comments": false,
+  "ignore": [
+    "interface.js"
+  ],
+  "presets": [
+    "@babel/preset-flow"
+  ],
+  "env": {
+    "production": {
+      "presets": [
+        "@babel/preset-flow",
+        ["@babel/preset-env", {
+          "modules": false
+        }]
+      ],
+      "plugins": [
+        "@babel/plugin-transform-modules-commonjs",
+        "@babel/plugin-proposal-class-properties",
+        "@babel/plugin-proposal-object-rest-spread"
+      ]
+    },
+    "test": {
+      "presets": [
+        "@babel/preset-flow",
+        "@babel/preset-env"
+      ],
+      "plugins": [
+        "@babel/plugin-transform-modules-commonjs",
+        "@babel/plugin-proposal-class-properties",
+        "@babel/plugin-proposal-object-rest-spread"
+      ]
+    }
+  }
+}

packages/mware-cors/README.md

@@ -0,0 +1,35 @@
+# @qiwi/mware-cors
+CORS middleware
+
+### Install
+```bash
+yarn add @qiwi/mware-cors
+npm i @qiwi/mware-cors
+```
+
+### Usage
+
+```javascript
+import cors from '@qiwi/mware-cors'
+import express from 'express'
+
+const app = express()
+app.use(cors())
+
+app.get('/foo/bar', (req, res) => {
+  res.send('foo')
+})
+
+/*
+ RES {
+  headers: { 
+    'Access-Control-Allow-Origin': '*',
+    'Access-Control-Allow-Methods': 'GET, HEAD, PATCH, PUT, POST, DELETE, OPTIONS'
+    ...
+  },
+  ...
+ }
+ */
+
+app.listen(...)
+```

packages/mware-cors/package.json

@@ -0,0 +1,35 @@
+{
+  "name": "@qiwi/mware-cors",
+  "version": "1.1.0",
+  "private": false,
+  "description": "CORS middleware",
+  "main": "dist/es5/index.js",
+  "files": [
+    "README.md",
+    "CHANGELOG.md",
+    "dist/"
+  ],
+  "scripts": {
+    "build_es6": "flow-remove-types src/ --out-dir dist/es6/",
+    "build_es5": "BABEL_ENV=production babel src --out-dir dist/es5/",
+    "build": "rm -rf dist && npm run build_es6 && npm run build_es5"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/qiwi/mware.git"
+  },
+  "keywords": [
+    "common middlewares"
+  ],
+  "author": "Anton Golub <a.golub@qiwi.com>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/qiwi/mware/issues"
+  },
+  "homepage": "https://github.com/qiwi/mware#readme",
+  "dependencies": {},
+  "devDependencies": {
+    "lodash": "^4.17.11",
+    "reqresnext": "^1.5.1"
+  }
+}

packages/mware-cors/src/index.js

@@ -0,0 +1,59 @@
+// @flow
+
+import type {
+  IAny,
+  IMiddlewareFactory,
+  IRegularMiddleware,
+  IRequest,
+  IResponse,
+  INext,
+  ILogger
+} from '../../mware-core/src/interface'
+
+export const ALLOW_ORIGIN = 'Access-Control-Allow-Origin'
+export const ALLOW_HEADERS = 'Access-Control-Allow-Headers'
+export const EXPOSE_HEADERS = 'Access-Control-Expose-Headers'
+export const ALLOW_METHODS = 'Access-Control-Allow-Methods'
+export const ALLOW_CREDENTIALS = 'Access-Control-Allow-Credentials'
+
+export const DEFAULT_HEADERS = {
+  [ALLOW_ORIGIN]: '*',
+  [ALLOW_HEADERS]: 'set-cookie, Authorization, Origin, X-Requested-With, Content-Type, Accept, Access-Control-Allow-Headers, Origin,Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers',
+  [EXPOSE_HEADERS]: 'Cookie, Set-Cookie, Location',
+  [ALLOW_METHODS]: 'GET, HEAD, PATCH, PUT, POST, DELETE, OPTIONS',
+  [ALLOW_CREDENTIALS]: 'true'
+}
+
+export const formatOriginHeader = (policy: IAny, origin: IAny): string => {
+  switch (policy) {
+    case 'echo':
+      return origin
+
+    case undefined:
+    case null:
+      return '*'
+
+    default:
+      return '' + policy
+  }
+}
+export type headers = typeof ALLOW_ORIGIN | typeof ALLOW_HEADERS | typeof EXPOSE_HEADERS | typeof ALLOW_METHODS | typeof ALLOW_CREDENTIALS
+export type IOpts = {
+  logger?: ILogger,
+  [headers]: ?string
+}
+
+export default ((opts: ?IOpts) => {
+  return ((req: IRequest, res: IResponse, next: INext) => {
+    const allowOrigin = formatOriginHeader(opts && opts[ALLOW_ORIGIN], req.get('origin'))
+    const corsHeaders = {
+      ...DEFAULT_HEADERS,
+      ...opts,
+      [ALLOW_ORIGIN]: allowOrigin
+    }
+
+    res.header(corsHeaders)
+
+    next()
+  }: IRegularMiddleware)
+}: IMiddlewareFactory)

packages/mware-cors/test/index.js

@@ -0,0 +1,53 @@
+import factory, {ALLOW_ORIGIN, ALLOW_METHODS } from '../src'
+import reqresnext from 'reqresnext'
+
+describe('mware-crumbs', () => {
+
+  beforeEach(() => {
+    jest.resetAllMocks()
+  })
+
+  it('factory returns a middleware', () => {
+    expect(factory()).toEqual(expect.any(Function))
+  })
+
+  describe('sets CORS headers', () => {
+    it('default', () => {
+      const mware = factory({})
+      const { req, res, next } = reqresnext(null, null, jest.fn())
+
+      mware(req, res, next)
+
+      expect(next).toHaveBeenCalled()
+      expect(res.get(ALLOW_ORIGIN)).toBe('*')
+    })
+
+    it('optional methods', () => {
+      const mware = factory({
+        [ALLOW_ORIGIN]: 'example.com',
+        [ALLOW_METHODS]: 'GET, PUT'
+      })
+      const { req, res, next } = reqresnext(null, null, jest.fn())
+
+      mware(req, res, next)
+
+      expect(next).toHaveBeenCalled()
+      expect(res.get(ALLOW_ORIGIN)).toBe('example.com')
+      expect(res.get(ALLOW_METHODS)).toBe('GET, PUT')
+    })
+
+    it('origin echo', () => {
+      const mware = factory({ [ALLOW_ORIGIN]: 'echo' })
+      const { req, res, next } = reqresnext({
+        headers: {
+          origin: 'www.example.com'
+        }
+      }, null, jest.fn())
+
+      mware(req, res, next)
+
+      expect(next).toHaveBeenCalled()
+      expect(res.get(ALLOW_ORIGIN)).toBe('www.example.com')
+    })
+  })
+})

packages/mware/src/index.js

@@ -1,10 +1,14 @@
 import mdc from '@qiwi/mware-mdc'
 import logger from '@qiwi/mware-logger'
+import crumbs from '@qiwi/mware-crumbs'
+import cors from '@qiwi/mware-cors'
 import { util } from '@qiwi/mware-core'
 
 export {
   mdc,
   logger,
+  cors,
+  crumbs,
   util
 }
 

packages/mware/test/index.js

@@ -1,9 +1,11 @@
-import {mdc, logger, util} from '../src'
+import {mdc, logger, util, cors, crumbs} from '../src'
 
 describe('mware', () => {
   it('exposes middlewares collection', () => {
     expect(mdc).toEqual(expect.any(Function))
     expect(logger).toEqual(expect.any(Function))
+    expect(cors).toEqual(expect.any(Function))
+    expect(crumbs).toEqual(expect.any(Function))
     expect(util).not.toBeUndefined()
   })
 })