lines-between-class-members

The --fix option on the command line can automatically fix some of the problems reported by this rule.

Requires or disallows an empty line between class members.

This rule improves readability by enforcing lines between class members. It will not check empty lines before the first member and after the last member, since that is already taken care of by padded-blocks.

Rule Details

Examples of incorrect code for this rule:

/* eslint lines-between-class-members: ["error", "always"]*/
class MyClass {
  x;
  foo() {
    //...
  }
  bar() {
    //...
  }
}

Examples of correct code for this rule:

/* eslint lines-between-class-members: ["error", "always"]*/
class MyClass {
  x;

  foo() {
    //...
  }

  bar() {
    //...
  }
}

Examples of additional correct code for this rule:

/* eslint lines-between-class-members: ["error", "always"]*/
class MyClass {
  x = 1

  ;in = 2
}

Options

This rule has a string option and an object option.

String option:

"always"(default) require an empty line after class members
"never" disallows an empty line after class members

Object option:

"exceptAfterSingleLine": false(default) do not skip checking empty lines after single-line class members
"exceptAfterSingleLine": true skip checking empty lines after single-line class members

Examples of incorrect code for this rule with the string option:

/* eslint lines-between-class-members: ["error", "always"]*/
class Foo{
  x;
  bar(){}
  baz(){}
}

/* eslint lines-between-class-members: ["error", "never"]*/
class Foo{
  x;

  bar(){}

  baz(){}
}

Examples of correct code for this rule with the string option:

/* eslint lines-between-class-members: ["error", "always"]*/
class Foo{
  x;

  bar(){}

  baz(){}
}

/* eslint lines-between-class-members: ["error", "never"]*/
class Foo{
  x;
  bar(){}
  baz(){}
}

Examples of correct code for this rule with the object option:

/* eslint lines-between-class-members: ["error", "always", { "exceptAfterSingleLine": true }]*/
class Foo{
  x; // single line class member
  bar(){} // single line class member
  baz(){
    // multi line class member
  }

  qux(){}
}

When Not To Use It

If you don't want to enforce empty lines between class members, you can disable this rule.

Compatibility

Version

This rule was introduced in ESLint 4.9.0.