Clean up our callback style and enforce no exclusive tests and remove…

… an exclusive test (#1900)

We use arrow functions in most places; this enforces it.

Passing arrow functions to Mocha is discouraged: https://mochajs.org/#arrow-functions

This was a mix of autofixes and hand adjustments.

.eslintrc-preferred.yml

@@ -20,7 +20,10 @@ rules:
   no-var: "error"
   prefer-const: "error"
   strict: "error"
+  arrow-body-style: ["error", "as-needed"]
 
   # Chai friendly.
   no-unused-expressions: "off"
   chai-friendly/no-unused-expressions: "error"
+
+  mocha/prefer-arrow-callback: "error"

.eslintrc.yml

@@ -7,6 +7,9 @@ env:
   es6: true
   mocha: true
 
+plugins:
+  - mocha
+
 extends:
   # Enable a set of unopinionated, style-agnostic rules which cover many
   # likely errors.
@@ -28,3 +31,6 @@ rules:
   eol-last: "error"
   object-curly-spacing: ["error", "always"]
   comma-dangle: ["error", "always-multiline"]
+
+  mocha/no-exclusive-tests: "error"
+  mocha/no-mocha-arrows: "error"

frontend/components/search-results.js

@@ -32,16 +32,11 @@ export default class SearchResults extends React.Component {
   }
 
   renderCategoryHeadings() {
-    return this.preparedExamples.map(function(category, i) {
-      return (
-        <Link
-          to={'/examples/' + category.category.id}
-          key={category.category.id}
-        >
-          <h3 id={category.category.id}>{category.category.name}</h3>
-        </Link>
-      )
-    })
+    return this.preparedExamples.map((category, i) => (
+      <Link to={'/examples/' + category.category.id} key={category.category.id}>
+        <h3 id={category.category.id}>{category.category.name}</h3>
+      </Link>
+    ))
   }
 
   render() {

lib/analytics.js

@@ -62,7 +62,7 @@ function defaultAnalytics() {
 function load() {
   const defaultAnalyticsObject = defaultAnalytics()
   if (useRedis) {
-    redis.get(analyticsPath, function(err, value) {
+    redis.get(analyticsPath, (err, value) => {
       if (err == null && value != null) {
         // if/try/return trick:
         // if error, then the rest of the function is run.

lib/github-auth.js

@@ -25,7 +25,7 @@ if (serverSecrets && serverSecrets.gh_token) {
 function setRoutes(server) {
   const baseUrl = process.env.BASE_URL || 'https://img.shields.io'
 
-  server.route(/^\/github-auth$/, function(data, match, end, ask) {
+  server.route(/^\/github-auth$/, (data, match, end, ask) => {
     if (!(serverSecrets && serverSecrets.gh_client_id)) {
       return end('This server is missing GitHub client secrets.')
     }
@@ -41,7 +41,7 @@ function setRoutes(server) {
     end('')
   })
 
-  server.route(/^\/github-auth\/done$/, function(data, match, end, ask) {
+  server.route(/^\/github-auth\/done$/, (data, match, end, ask) => {
     if (
       !(
         serverSecrets &&
@@ -68,7 +68,7 @@ function setRoutes(server) {
       }),
       method: 'POST',
     }
-    request(options, function(err, res, body) {
+    request(options, (err, res, body) => {
       if (err != null) {
         return end('The connection to GitHub failed.')
       }
@@ -96,16 +96,16 @@ function setRoutes(server) {
           '<p><a href="/">Back to the website</a></p>'
       )
 
-      sendTokenToAllServers(token).catch(function(e) {
+      sendTokenToAllServers(token).catch(e => {
         console.error('GitHub user token transmission failed:', e)
       })
     })
   })
 
-  server.route(/^\/github-auth\/add-token$/, function(data, match, end, ask) {
+  server.route(/^\/github-auth\/add-token$/, (data, match, end, ask) => {
     if (!secretIsValid(data.shieldsSecret)) {
       // An unknown entity tries to connect. Let the connection linger for 10s.
-      return setTimeout(function() {
+      return setTimeout(() => {
         end('Invalid secret.')
       }, 10000)
     }
@@ -117,33 +117,34 @@ function setRoutes(server) {
 function sendTokenToAllServers(token) {
   const ips = serverSecrets.shieldsIps
   return Promise.all(
-    ips.map(function(ip) {
-      return new Promise(function(resolve, reject) {
-        const options = {
-          url: 'https://' + ip + '/github-auth/add-token',
-          method: 'POST',
-          form: {
-            shieldsSecret: serverSecrets.shieldsSecret,
-            token: token,
-          },
-          // We target servers by IP, and we use HTTPS. Assuming that
-          // 1. Internet routers aren't hacked, and
-          // 2. We don't unknowingly lose our IP to someone else,
-          // we're not leaking people's and our information.
-          // (If we did, it would have no impact, as we only ask for a token,
-          // no GitHub scope. The malicious entity would only be able to use
-          // our rate limit pool.)
-          // FIXME: use letsencrypt.
-          strictSSL: false,
-        }
-        request(options, function(err, res, body) {
-          if (err != null) {
-            return reject(err)
+    ips.map(
+      ip =>
+        new Promise((resolve, reject) => {
+          const options = {
+            url: 'https://' + ip + '/github-auth/add-token',
+            method: 'POST',
+            form: {
+              shieldsSecret: serverSecrets.shieldsSecret,
+              token: token,
+            },
+            // We target servers by IP, and we use HTTPS. Assuming that
+            // 1. Internet routers aren't hacked, and
+            // 2. We don't unknowingly lose our IP to someone else,
+            // we're not leaking people's and our information.
+            // (If we did, it would have no impact, as we only ask for a token,
+            // no GitHub scope. The malicious entity would only be able to use
+            // our rate limit pool.)
+            // FIXME: use letsencrypt.
+            strictSSL: false,
           }
-          resolve()
+          request(options, (err, res, body) => {
+            if (err != null) {
+              return reject(err)
+            }
+            resolve()
+          })
         })
-      })
-    })
+    )
   )
 }
 
@@ -179,9 +180,7 @@ function isTokenUsable(token, now) {
 // with a reasonable chance that the request will succeed.
 function usableTokens() {
   const now = utcEpochSeconds()
-  return githubUserTokens.filter(function(token) {
-    return isTokenUsable(token, now)
-  })
+  return githubUserTokens.filter(token => isTokenUsable(token, now))
 }
 
 // Retrieve a user token if there is one for which we believe there are requests
@@ -308,7 +307,7 @@ function githubRequest(request, url, query, cb) {
     url += '?' + qs
   }
 
-  request(url, { headers: headers }, function(err, res, buffer) {
+  request(url, { headers: headers }, (err, res, buffer) => {
     if (globalToken !== null && githubToken !== null && err === null) {
       if (res.statusCode === 401) {
         // Unauthorized.

lib/github-provider.js

@@ -14,7 +14,7 @@ const { age } = require('./color-formatters')
 function mapGithubCommitsSince({ camp, cache }, githubApiProvider) {
   camp.route(
     /^\/github\/commits-since\/([^/]+)\/([^/]+)\/([^/]+)\.(svg|png|gif|jpg|json)$/,
-    cache(function(data, match, sendBadge, request) {
+    cache((data, match, sendBadge, request) => {
       const user = match[1] // eg, SubtitleEdit
       const repo = match[2] // eg, subtitleedit
       const version = match[3] // eg, 3.4.7 or latest
@@ -73,7 +73,7 @@ function mapGithubCommitsSince({ camp, cache }, githubApiProvider) {
 function mapGithubReleaseDate({ camp, cache }, githubApiProvider) {
   camp.route(
     /^\/github\/(release-date|release-date-pre)\/([^/]+)\/([^/]+)\.(svg|png|gif|jpg|json)$/,
-    cache(function(data, match, sendBadge, request) {
+    cache((data, match, sendBadge, request) => {
       const releaseType = match[1] // eg, release-date-pre / release-date
       const user = match[2] // eg, microsoft
       const repo = match[3] // eg, vscode

lib/licenses.spec.js

@@ -3,7 +3,7 @@
 const { test, given } = require('sazerac')
 const { licenseToColor } = require('./licenses')
 
-describe('license helpers', () => {
+describe('license helpers', function() {
   test(licenseToColor, () => {
     given('MIT').expect('green')
     given('MPL-2.0').expect('orange')

lib/load-logos.js

@@ -9,7 +9,7 @@ function loadLogos() {
   const logos = {}
   const logoDir = path.join(__dirname, '..', 'logo')
   const logoFiles = fs.readdirSync(logoDir)
-  logoFiles.forEach(function(filename) {
+  logoFiles.forEach(filename => {
     if (filename[0] === '.') {
       return
     }

lib/load-simple-icons.js

@@ -4,7 +4,7 @@ const simpleIcons = require('simple-icons')
 const { svg2base64 } = require('./logo-helper')
 
 function loadSimpleIcons() {
-  Object.keys(simpleIcons).forEach(function(key) {
+  Object.keys(simpleIcons).forEach(key => {
     const k = key.toLowerCase().replace(/ /g, '-')
     if (k !== key) {
       simpleIcons[k] = simpleIcons[key]

lib/log.js

@@ -37,7 +37,7 @@ const throttledConsoleError = throttle(console.error, 10000, {
 module.exports.error = function error(...msg) {
   const d = date()
   listeners.forEach(f => f(d, ...msg))
-  Raven.captureException(msg, function(sendErr) {
+  Raven.captureException(msg, sendErr => {
     if (sendErr) {
       throttledConsoleError(
         'Failed to send captured exception to Sentry',

lib/log.spec.js

@@ -12,27 +12,25 @@ function requireUncached(module) {
   return require(module)
 }
 
-describe('log', () => {
-  describe('error', () => {
-    before(() => {
+describe('log', function() {
+  describe('error', function() {
+    before(function() {
       this.clock = sinon.useFakeTimers()
-      sinon
-        .stub(Raven, 'captureException')
-        .callsFake(function fakeFn(e, callback) {
-          callback(new Error(`Cannot send message "${e}" to Sentry.`))
-        })
+      sinon.stub(Raven, 'captureException').callsFake((e, callback) => {
+        callback(new Error(`Cannot send message "${e}" to Sentry.`))
+      })
       // we have to create a spy before requiring 'error' function
       sinon.spy(console, 'error')
       this.error = requireUncached('./log').error
     })
 
-    after(() => {
+    after(function() {
       this.clock.restore()
       console.error.restore()
       Raven.captureException.restore()
     })
 
-    it('should throttle errors from Raven client', () => {
+    it('should throttle errors from Raven client', function() {
       this.error('test error 1')
       this.error('test error 2')
       this.error('test error 3')

lib/luarocks-version.js

@@ -30,7 +30,7 @@ exports.compareVersionLists = compareVersionLists
 function parseVersion(versionString) {
   versionString = versionString.toLowerCase().replace('-', '.')
   const versionList = []
-  versionString.split('.').forEach(function(versionPart) {
+  versionString.split('.').forEach(versionPart => {
     const parsedPart = /(\d*)([a-z]*)(\d*)/.exec(versionPart)
     if (parsedPart[1]) {
       versionList.push(parseInt(parsedPart[1]))

lib/make-badge.js

@@ -14,7 +14,7 @@ const badgeKeyWidthCache = new LruCache(1000)
 const templates = {}
 const templateFiles = fs.readdirSync(path.join(__dirname, '..', 'templates'))
 dot.templateSettings.strip = false // Do not strip whitespace.
-templateFiles.forEach(async function(filename) {
+templateFiles.forEach(async filename => {
   if (filename[0] === '.') {
     return
   }
@@ -29,7 +29,7 @@ templateFiles.forEach(async function(filename) {
     // Substitute dot code.
     const mapping = new Map()
     let mappingIndex = 1
-    const untemplatedSvg = templateData.replace(/{{.*?}}/g, function(match) {
+    const untemplatedSvg = templateData.replace(/{{.*?}}/g, match => {
       // Weird substitution that currently works for all templates.
       const mapKey = '99999990' + mappingIndex + '.1'
       mappingIndex++
@@ -52,9 +52,9 @@ templateFiles.forEach(async function(filename) {
     // Substitute dot code back.
     let svg = data
     const unmappedKeys = []
-    mapping.forEach(function(value, key) {
+    mapping.forEach((value, key) => {
       let keySubstituted = false
-      svg = svg.replace(RegExp(key, 'g'), function() {
+      svg = svg.replace(RegExp(key, 'g'), () => {
         keySubstituted = true
         return value
       })