Configure ESLint (#28)

.circleci/config.yml

@@ -42,6 +42,7 @@ jobs:
       - *run_yarn_install
       - *save_build_cache
       - run: yarn prettier-ci
+      - run: yarn lint:js
 
 workflows:
   version: 2

.eslintrc

@@ -0,0 +1,13 @@
+{
+  "extends": [
+    "amo",
+  ],
+  "env": {
+    "node": true
+  },
+  "rules": {
+    "import/no-extraneous-dependencies": ["error", {
+      "devDependencies": true
+    }]
+  }
+}

.eslintrc.js

@@ -1,16 +0,0 @@
-module.exports = {
-  env: {
-    node: true,
-  },
-  plugins: ['prettier'],
-  extends: ['prettier'],
-  parserOptions: {
-    ecmaVersion: 2018,
-  },
-  rules: {
-    'prettier/prettier': 'error',
-    'linebreak-style': ['error', 'unix'],
-    quotes: ['error', 'single'],
-    semi: ['error', 'always'],
-  },
-};

eleventy.config.js

@@ -8,19 +8,17 @@ const syntaxHighlight = require('@11ty/eleventy-plugin-syntaxhighlight');
 const xmlFiltersPlugin = require('eleventy-xml-plugin');
 const Nunjucks = require('nunjucks');
 
-const slugify = require('./libs/slugify');
-
 const inputDir = path.relative(__dirname, 'src/content');
 const wpInputDir = path.relative(__dirname, 'src/wp-content');
 const outputDir = path.relative(__dirname, 'build');
 
 const buildWordpressTheme = process.env.BUILD_WORDPRESS_THEME === '1';
 
-const window = new JSDOM('').window;
+const { window } = new JSDOM('');
 const DOMPurify = createDOMPurify(window);
 const defaultNunjucksEnv = new Nunjucks.Environment();
 
-module.exports = function (eleventyConfig) {
+module.exports = function configure(eleventyConfig) {
   // Tell the config to not use gitignore for ignores.
   eleventyConfig.setUseGitIgnore(false);
 
@@ -30,6 +28,7 @@ module.exports = function (eleventyConfig) {
       return;
     }
 
+    // eslint-disable-next-line consistent-return
     return defaultNunjucksEnv.filters.safe(
       DOMPurify.sanitize(value.toString())
     );
@@ -45,7 +44,7 @@ module.exports = function (eleventyConfig) {
 
   eleventyConfig.addFilter('postAuthors', (allAuthors, postAuthor) => {
     return allAuthors.filter((item) => {
-      return postAuthor == item.id;
+      return postAuthor === item.id;
     });
   });
 
@@ -57,11 +56,14 @@ module.exports = function (eleventyConfig) {
         break;
       }
     }
+
     if (postIndex >= 0 && allPosts && allPosts.length) {
       if (postIndex + modifier >= 0 && postIndex + modifier < allPosts.length) {
         return allPosts[postIndex + modifier];
       }
     }
+
+    return null;
   }
 
   eleventyConfig.addFilter('getPrevPost', (allPosts, currentPost) => {
@@ -72,8 +74,6 @@ module.exports = function (eleventyConfig) {
     return getPost(allPosts, currentPost, 1);
   });
 
-  eleventyConfig.addFilter('slugify', slugify);
-
   // Explicitly copy through the built files needed.
   eleventyConfig.addPassthroughCopy({
     './src/content/robots.txt': 'robots.txt',
@@ -89,7 +89,7 @@ module.exports = function (eleventyConfig) {
 
   eleventyConfig.setBrowserSyncConfig({
     callbacks: {
-      ready: function (err, bs) {
+      ready(err, bs) {
         bs.addMiddleware('*', (req, res) => {
           const content_404 = fs.readFileSync('./build/404.html');
           // Provides the 404 content without redirect.

libs/slugify.js

@@ -1,10 +0,0 @@
-const slugify = require('slugify');
-
-module.exports = (() => {
-  const slugifier = (string) =>
-    slugify(string, {
-      replacement: '-',
-      lower: true,
-    });
-  return slugifier;
-})();

package.json

@@ -22,7 +22,8 @@
     "sass:watch": "chokidar 'src/assets/css/**/*.scss' -c 'npm run sass:build'",
     "script:build": "bin/build-script",
     "script:watch": "chokidar 'src/assets/js/*.js' -c 'npm run script:build'",
-    "lint:php": "find build -name '*.php' -print0 | xargs -0 -n1 -P8 php -l"
+    "lint:php": "find build -name '*.php' -print0 | xargs -0 -n1 -P8 php -l",
+    "lint:js": "eslint ."
   },
   "devDependencies": {
     "@11ty/eleventy": "^0.11.1",
@@ -31,9 +32,11 @@
     "chokidar-cli": "^2.1.0",
     "dompurify": "^2.2.6",
     "eleventy-xml-plugin": "^0.1.0",
-    "eslint": "^7.21.0",
+    "eslint": "^7.22.0",
+    "eslint-config-amo": "^4.3.0",
     "flat-cache": "^3.0.4",
     "fs-extra": "^9.1.0",
+    "jest": "^26.6.3",
     "jsdom": "^16.5.1",
     "luxon": "^1.26.0",
     "markdown-it-container": "^3.0.0",
@@ -41,6 +44,7 @@
     "node-sass": "^5.0.0",
     "normalize.css": "^8.0.1",
     "npm-run-all": "^4.1.5",
+    "nunjucks": "^3.2.3",
     "photon-colors": "^3.3.2",
     "prettier": "^2.2.1",
     "pretty-quick": "^3.1.0",

src/assets/js/new-tab-links.js

@@ -1,10 +1,11 @@
-(function () {
+/* global window, document */
+(function newTabLinks() {
   const links = document.querySelectorAll('a');
   const relAttrs = 'noreferrer noopener';
 
   for (let i = 0; i < links.length; i++) {
     const a = links[i];
-    if (a.hostname != location.hostname) {
+    if (a.hostname !== window.location.hostname) {
       a.rel = a.rel.length ? `${a.rel} ${relAttrs}` : relAttrs;
       a.target = '_blank';
     }

src/wordpress.js

@@ -1,8 +1,9 @@
 // Based on fetching + caching in https://github.com/samikeijonen/11ty-wp ❤️
 
+const path = require('path');
+
 const fetch = require('node-fetch');
 const flatcache = require('flat-cache');
-const path = require('path');
 const { DateTime } = require('luxon');
 
 async function getNumPages(endPoint) {
@@ -14,6 +15,7 @@ async function fetchAll({ numPages, endPoint, type }) {
   const allPages = [];
   let allData = [];
 
+  // eslint-disable-next-line no-console
   console.debug(`Fetching ${type} content from wordpress via REST API`);
 
   for (let pageNum = 1; pageNum <= numPages; pageNum++) {
@@ -23,7 +25,7 @@ async function fetchAll({ numPages, endPoint, type }) {
   }
 
   const results = await Promise.all(allPages);
-  for (result of results) {
+  for (const result of results) {
     let json = await result.json();
 
     // Filter post data and only cache what we care about.
@@ -76,7 +78,8 @@ async function fetchAll({ numPages, endPoint, type }) {
 async function fetchData(type, endPoint) {
   const baseURL =
     process.env.WORDPRESS_BASE_URL || 'https://mozamo.wpengine.com';
-  console.log(`WordPress base URL: ${baseURL}`);
+  // eslint-disable-next-line no-console
+  console.debug(`WordPress base URL: ${baseURL}`);
 
   const url = `${baseURL}/${endPoint}`;