add specs for crawler service

mocks/logger.mock.js

@@ -0,0 +1,9 @@
+const EventEmitter = require('events')
+
+class MockLogger extends EventEmitter {
+  log({ message, level, service }) {
+    this.emit('test:log', { message, level, service })
+  }
+}
+
+module.exports = MockLogger

mocks/request.mock.js

@@ -0,0 +1,31 @@
+const sinon = jest.requireActual('sinon')
+
+let currentSpy = null
+
+const mockRequest = (options) => {
+  try {
+    const spy = currentSpy || sinon.spy()
+
+    console.info(`mock request ${JSON.stringify(options)}`)
+    spy(options)
+  } catch (err) {
+    console.trace(err)
+  }
+}
+
+const setRequestSpy = () => {
+  const spy = sinon.spy()
+
+  currentSpy = spy
+  return spy
+}
+
+const clearRequestSpy = () => {
+  currentSpy = null
+}
+
+module.exports = {
+  mockRequest,
+  setRequestSpy,
+  clearRequestSpy,
+}

package.json

@@ -11,7 +11,7 @@
     "start": "node lib/index.js",
     "start:dev": "NODE_ENV=development PORT=3000 nodemon lib/index.js",
     "start:dev:inspect": "NODE_ENV=development PORT=3000 nodemon --inspect lib/index.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "jest"
   },
   "keywords": [
     "facebook",
@@ -37,6 +37,10 @@
     "winston-daily-rotate-file": "^4.2.1"
   },
   "devDependencies": {
-    "nodemon": "^1.19.3"
+    "chai": "^4.2.0",
+    "chai-sinon": "^2.8.1",
+    "jest": "^26.1.0",
+    "nodemon": "^1.19.3",
+    "sinon": "^9.0.2"
   }
 }

test/services/crawler.spec.js

@@ -0,0 +1,74 @@
+const chai = require('chai')
+const sinon = require('sinon')
+const { expect } = chai
+const chaiSinon = require('chai-sinon')
+const { mockRequest, setRequestSpy, clearRequestSpy } = require('../../mocks/request.mock')
+
+const crawl = require('../../lib/services/crawler')
+const MockLogger = require('../../mocks/logger.mock')
+
+chai.use(chaiSinon)
+jest.mock('request', () => mockRequest)
+
+describe(crawl, () => {
+  let logger
+  let request
+
+  beforeEach(() => {
+    logger = new MockLogger()
+    clearRequestSpy()
+  })
+
+  it('should return promise', () => {
+    const promise = crawl('https://abc.xyz', { logger })
+
+    expect(promise).to.be.instanceOf(Promise)
+  })
+
+  it('should level log message', (callback) => {
+    logger.on('test:log', ({ message, level, service }) => {
+      expect(message).to.equal('Crawl started for url: https://abc.xyz')
+      expect(level).to.equal('info')
+      expect(service).to.equal('parser')
+      callback()
+    })
+
+    crawl('https://abc.xyz', { logger })
+  })
+
+
+  it('should call request', () => {
+    const spy = setRequestSpy()
+
+    crawl('https://abc.xyz', { logger })
+
+    expect(spy).to.have.been.calledOnce
+  })
+
+
+  it('should call request with URL', () => {
+    const spy = setRequestSpy()
+
+    crawl('https://zzz.yyy', { logger })
+
+    expect(spy.args[0][0].url).to.equal('https://zzz.yyy')
+  })
+
+
+  it('should call request with `Accept-Language` header value', () => {
+    const spy = setRequestSpy()
+
+    crawl('https://zzz.yyy', { logger })
+
+    expect(spy.args[0][0].headers).to.have.property('Accept-Language', 'en-US, en')
+  })
+
+
+  it('should call request with `User-Agent` header value', () => {
+    const spy = setRequestSpy()
+
+    crawl('https://zzz.yyy', { logger })
+
+    expect(spy.args[0][0].headers).to.have.property('User-Agent', 'request')
+  })
+})