ESLint / Nodejs：由于默认开关大小写而导致错误掉线

Question

While trying to validate my .js file using ESLint I received a an unexpected lexical declaration (no-case declarations) error.

c:\>eslint C:\modules\myFile.js

503:17  error  Unexpected lexical declaration in case block        no-case-declarations

Following is my code that is causing the error

switch (type) {
case String(type.match(/.*test.*/i)):                        
        console.log('test')
        break;
default:
    console.log('error')
    return err;
}

There is no error shown in vs-code for this. When i transform my code like:

switch (type) {
case String(type.match(/.*test.*/i)):                        
        console.log('test')
        break;
/*default:
    console.log('error')
    return err;*/
}

all errors disappear so I am thinking it must be coming off the default case block.

Following is my esLint.rc:

{
    "root": true,
    "parserOptions": {
        "ecmaVersion": 6,
        "sourceType": "script"
    },
    "env": {
        "node": true,
        "browser": false
    },
    "extends": "eslint:recommended",
    "rules": {
        "semi": ["error", "always"],
        "indent": ["error", 4, {
            "VariableDeclarator": 2,
            "SwitchCase": 1,
            "MemberExpression": 1,
            "ArrayExpression": "first"
        }],
        "no-mixed-requires": "off",
        "no-restricted-imports": "off",
        "no-undef":"off",
        "no-console":2,
        "no-trailing-spaces": "error",
        "no-unused-vars": "warn"
    }
}

What could be the issue here? As far as i read, the default ESLint rules have a default-case rule but not a no-default-enforced rule.

Answer 1

This is a tricky one cause it's not quite what you think. The default not having {...} is the problem. So changing default: to default: { ... } will fix this. If you want to turn it off, you'll have to remove an extension in eslint.

Specifically, this is being produced by the "extends" : "eslint:recommended"

More information here