How to add new line after and before method declarations in classes using prettier?

Question

What settings need to be configured to add a new line before and after method declaration in classes in typescript files using prettier plugin in vs code editor?

How can we achieve by writing any rule in .prettierrc or tslint.json file?

current behavior is

function one(){
// some code
}
function two(){
// some code
}

expected result

function one(){
// some code
}

function two(){
// some code
}

I have tried with below line in tslint.json

"lines-between-class-methods": "true"

but did not works

Answer 1

What @lakshan mentions is an ESLint rule. There is a TSLint rule that accomplishes what you are looking for but on in regards to class methods.

https://github.com/chinchiheather/tslint-lines-between-class-members

Run

npm install --save-dev tslint-lines-between-class-members

Add

tslint.json

{
  "rulesDirectory": [
    "node_modules/tslint-lines-between-class-members"
  ],
  "rules": {
    "lines-between-class-members": true,
  }
}

Answer 2

lines-between-class-members is a built-in of ESLint, the replacement of TSLint which is now deprecated. This rule works for both TypeScript and JavaScript and --fix is supported. See https://eslint.org/docs/rules/lines-between-class-members for full details. You probably want to set exceptAfterSingleLine to true for TypeScript.

To make ESLint work for TypeScript you have to install npm packages @typescript-eslint/parser and @typescript-eslint/eslint-plugin and include both parser and plugin in your ESLint config. See typescript-eslint docs.

{
  "parser": "@typescript-eslint/parser",
  "plugins": ["@typescript-eslint"],
  "rules": {
    "lines-between-class-members": ["error", "always", { "exceptAfterSingleLine": true }]
  }
}