Lint: Let eslint do its job

Signed-off-by: Knut Ahlers <knut@ahlers.me>

frontend/.eslintrc.js

@@ -0,0 +1,84 @@
+// https://eslint.org/docs/user-guide/configuring
+
+module.exports = {
+  'root': true,
+  'parserOptions': {
+    parser: 'babel-eslint',
+    ecmaVersion: 2018,
+  },
+  'env': {
+    browser: true,
+  },
+  'extends': [
+    // https://github.com/standard/standard/blob/master/docs/RULES-en.md
+    'eslint:recommended',
+  ],
+  'globals': {
+    axios: true,
+    L: true,
+    moment: true,
+    process: true,
+    Vue: true,
+  },
+  // add your custom rules here
+  'rules': {
+    'array-bracket-newline': ['error', { multiline: true }],
+    'array-bracket-spacing': ['error'],
+    'arrow-body-style': ['error', 'as-needed'],
+    'arrow-parens': ['error', 'as-needed'],
+    'arrow-spacing': ['error', { before: true, after: true }],
+    'block-spacing': ['error'],
+    'brace-style': ['error', '1tbs'],
+    'comma-dangle': ['error', 'always-multiline'], // Apply Contentflow rules
+    'comma-spacing': ['error'],
+    'comma-style': ['error', 'last'],
+    'curly': ['error'],
+    'dot-location': ['error', 'property'],
+    'dot-notation': ['error'],
+    'eol-last': ['error', 'always'],
+    'eqeqeq': ['error', 'always', { 'null': 'ignore' }],
+    'func-call-spacing': ['error', 'never'],
+    'function-paren-newline': ['error', 'multiline'],
+    'generator-star-spacing': ['off'], // allow async-await
+    'implicit-arrow-linebreak': ['error'],
+    'indent': ['error', 2],
+    'key-spacing': ['error', { beforeColon: false, afterColon: true, mode: 'strict' }],
+    'keyword-spacing': ['error'],
+    'linebreak-style': ['error', 'unix'],
+    'lines-between-class-members': ['error'],
+    'multiline-comment-style': ['warn'],
+    'newline-per-chained-call': ['error'],
+    'no-console': ['off'],
+    'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off', // allow debugger during development
+    'no-else-return': ['error'],
+    'no-extra-parens': ['error'],
+    'no-implicit-coercion': ['error'],
+    'no-lonely-if': ['error'],
+    'no-multiple-empty-lines': ['warn', { max: 2, maxEOF: 0, maxBOF: 0 }],
+    'no-multi-spaces': ['error'],
+    'no-trailing-spaces': ['error'],
+    'no-unneeded-ternary': ['error'],
+    'no-useless-return': ['error'],
+    'no-whitespace-before-property': ['error'],
+    'object-curly-newline': ['error', { consistent: true }],
+    'object-curly-spacing': ['error', 'always'],
+    'object-shorthand': ['error'],
+    'padded-blocks': ['error', 'never'],
+    'prefer-arrow-callback': ['error'],
+    'prefer-const': ['error'],
+    'prefer-object-spread': ['error'],
+    'prefer-template': ['error'],
+    'quote-props': ['error', 'consistent-as-needed', { keywords: true }],
+    'quotes': ['error', 'single', { allowTemplateLiterals: true }],
+    'semi': ['error', 'never'],
+    'space-before-blocks': ['error', 'always'],
+    'spaced-comment': ['warn', 'always'],
+    'space-infix-ops': ['error'],
+    'space-in-parens': ['error', 'never'],
+    'space-unary-ops': ['error', { words: true, nonwords: false }],
+    'switch-colon-spacing': ['error'],
+    'unicode-bom': ['error', 'never'],
+    'wrap-iife': ['error'],
+    'yoda': ['error'],
+  },
+}

frontend/app.js

@@ -1,4 +1,4 @@
-const app = new Vue({
+window.app = new Vue({
 
   created() {
     // Use defaults with custom icon paths
@@ -9,11 +9,14 @@ const app = new Vue({
       shadowUrl: '/asset/leaflet/marker-shadow.png',
     })
 
-    // This is only to detect another user updated the location
+    /*
-    // therefore this is NOT cryptographically safe!
+     * This is only to detect another user updated the location
+     * therefore this is NOT cryptographically safe!
+     */
     this.browserID = localStorage.getItem('browserID')
     if (!this.browserID) {
-      this.browserID = Math.random().toString(16).substr(2)
+      this.browserID = Math.random().toString(16)
+        .substr(2)
       localStorage.setItem('browserID', this.browserID)
     }
   },
@@ -38,12 +41,11 @@ const app = new Vue({
   methods: {
     initMap() {
       this.map = L.map('map')
-        .setView([0,0], 13)
+        .setView([0, 0], 13)
 
       L.tileLayer('https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
-        attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'
+        attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors',
       }).addTo(this.map)
-
     },
 
     shareLocation() {
@@ -73,9 +75,9 @@ const app = new Vue({
       this.socket = new WebSocket(`${window.location.href.split('#')[0].replace(/^http/, 'ws')}/ws`)
       this.socket.onclose = () => window.setTimeout(this.subscribe, 1000) // Restart socket
       this.socket.onmessage = evt => {
-        let loc= JSON.parse(evt.data)
+        const loc = JSON.parse(evt.data)
         loc.time = new Date(loc.time)
-        this.loc= loc
+        this.loc = loc
       }
     },
 
@@ -95,7 +97,7 @@ const app = new Vue({
       const center = [this.loc.lat, this.loc.lon]
 
       if (!this.marker) {
-        this.marker = L.marker(center, {icon:this.icon})
+        this.marker = L.marker(center, { icon: this.icon })
           .addTo(this.map)
       }