let variable = 'value'
if (variable = 'should not match') {
    console.log('Oops! 😩')
}
console.log(variable)

let variable = 'value'
if ('should not match' = variable) {
    console.log('this will never happen! 😏')
}

var object = {
    trailing  : 'comma',
    unchanged : 'line'
}

var object = {
    trailing  : 'comma',
    clean     : 'only insert this line',
    unchanged : 'line',
    dirty     : 'add comma above',
}

diff -u version-1.js version-2.js

--- version-1.js	2022-11-30 09:06:25.640608070 +0545
+++ version-2.js	2022-11-30 09:06:25.650608070 +0545
@@ -1,4 +1,6 @@
 var object = {
     trailing  : 'comma',
-    unchanged : 'line'
+    clean     : 'only insert this line',
+    unchanged : 'line',
+    dirty     : 'add comma above',
 }

module.exports = {
    rules : {
        'yoda'         : ['error', 'always'],
        'comma-dangle' : ['error', 'always-multiline'],
    }
}

module.exports = {
    extends : [
        'eslint:recommended',
    ],

    rules : {
        'yoda'         : ['error', 'always'],
        'comma-dangle' : ['error', 'always-multiline'],
    }
}

rules : {
    'max-len' : [ 'error', {
        code : 120,  // its hard I know 🤕
        ignoreStrings: true,
        ignoreTrailingComments: true,
    }],

    // stop it ✋, its time to split into files
    'max-lines' : [ 'error', {
        max : 500,
        skipBlankLines : true,
        skipComments : true,
    }],
}

rules : {
    'indent' : [
        'error',
        4, // 2 it less, 4 is good, 8 is excessive
        { SwitchCase : 1 },
    ],
    'max-depth' : [ 'error', 5 ],
    'brace-style' : [
        'error',
        '1tbs',  // one true brace style 👑
        { allowSingleLine: true },
    ],
}

rules : {
    'no-unused-vars' : [ 'error', {
        args : 'none',  // for callback
    }],
}

/* eslint no-fallthrough: error */
/* eslint no-console: off */

switch ('match') {
    case 'match':
        console.log('no break here 👇')
        // break
    case 'not a match':
        console.log('should not be here')
}

eslint no-fallthrough.js

console.log('why this is in production')

// eslint-disable-next-line no-console
console.log('this is allowed')

console.log('trialing noqa') // eslint-disable-line no-console

eslint no-console.js

function foo {
    return 'module is expected to be'
}

/* global boo */
function boo {
    return 'setting global will stop pesky linter'
}

module.exports = {
    env : { // just showing options
        browser  : true,
        node     : true,
        commonjs : true,
        es6      : true,
    }
}