This rule was deprecated in ESLint v8.53.0. Please use the corresponding rule in @stylistic/eslint-plugin-js.
Some style guides require block statements to start and end with blank lines. The goal is to improve readability by visually separating the block content and the surrounding code.
if (a) {
    b();
}Since it's good to have a consistent code style, you should either always write padded blocks or never do it.
Rule Details 
This rule enforces consistent empty line padding within blocks.
Options 
This rule has two options, the first one can be a string option or an object option. The second one is an object option, it can allow exceptions.
First option 
String option:
"always"(default) requires empty lines at the beginning and ending of block statements, function bodies, class static blocks, classes, andswitchstatements."never"disallows empty lines at the beginning and ending of block statements, function bodies, class static blocks, classes, andswitchstatements.
Object option:
"blocks"require or disallow padding within block statements, function bodies, and class static blocks"classes"require or disallow padding within classes"switches"require or disallow padding withinswitchstatements
Second option 
"allowSingleLineBlocks": trueallows single-line blocks
always 
Examples of incorrect code for this rule with the default "always" option:
::: incorrect
/*eslint padded-blocks: ["error", "always"]*/
if (a) {
    b();
}
if (a) { b(); }
if (a)
{
    b();
}
if (a) {
    b();
}
if (a) {
    // comment
    b();
}
class C {
    static {
        a();
    }
}:::
Examples of correct code for this rule with the default "always" option:
::: correct
/*eslint padded-blocks: ["error", "always"]*/
if (a) {
    b();
}
if (a)
{
    b();
}
if (a) {
    // comment
    b();
}
class C {
    static {
        a();
    }
}:::
never 
Examples of incorrect code for this rule with the "never" option:
::: incorrect
/*eslint padded-blocks: ["error", "never"]*/
if (a) {
    b();
}
if (a)
{
    b();
}
if (a) {
    b();
}
if (a) {
    b();
}
class C {
    static {
        a();
    }
}:::
Examples of correct code for this rule with the "never" option:
::: correct
/*eslint padded-blocks: ["error", "never"]*/
if (a) {
    b();
}
if (a)
{
    b();
}
class C {
    static {
        a();
    }
}:::
blocks 
Examples of incorrect code for this rule with the { "blocks": "always" } option:
::: incorrect
/*eslint padded-blocks: ["error", { "blocks": "always" }]*/
if (a) {
    b();
}
if (a) { b(); }
if (a)
{
    b();
}
if (a) {
    b();
}
if (a) {
    b();
}
if (a) {
    // comment
    b();
}
class C {
    static {
        a();
    }
}:::
Examples of correct code for this rule with the { "blocks": "always" } option:
::: correct
/*eslint padded-blocks: ["error", { "blocks": "always" }]*/
if (a) {
    b();
}
if (a)
{
    b();
}
if (a) {
    // comment
    b();
}
class C {
    static {
        a();
    }
}
class D {
    static {
        a();
    }
}:::
Examples of incorrect code for this rule with the { "blocks": "never" } option:
::: incorrect
/*eslint padded-blocks: ["error", { "blocks": "never" }]*/
if (a) {
    b();
}
if (a)
{
    b();
}
if (a) {
    b();
}
if (a) {
    b();
}
class C {
    static {
        a();
    }
}:::
Examples of correct code for this rule with the { "blocks": "never" } option:
::: correct
/*eslint padded-blocks: ["error", { "blocks": "never" }]*/
if (a) {
    b();
}
if (a)
{
    b();
}
class C {
    static {
        a();
    }
}
class D {
    static {
        a();
    }
}:::
classes 
Examples of incorrect code for this rule with the { "classes": "always" } option:
::: incorrect
/*eslint padded-blocks: ["error", { "classes": "always" }]*/
class  A {
    constructor(){
    }
}:::
Examples of correct code for this rule with the { "classes": "always" } option:
::: correct
/*eslint padded-blocks: ["error", { "classes": "always" }]*/
class  A {
    constructor(){
    }
}:::
Examples of incorrect code for this rule with the { "classes": "never" } option:
::: incorrect
/*eslint padded-blocks: ["error", { "classes": "never" }]*/
class  A {
    constructor(){
    }
}:::
Examples of correct code for this rule with the { "classes": "never" } option:
::: correct
/*eslint padded-blocks: ["error", { "classes": "never" }]*/
class  A {
    constructor(){
    }
}:::
switches 
Examples of incorrect code for this rule with the { "switches": "always" } option:
::: incorrect
/*eslint padded-blocks: ["error", { "switches": "always" }]*/
switch (a) {
    case 0: foo();
}:::
Examples of correct code for this rule with the { "switches": "always" } option:
::: correct
/*eslint padded-blocks: ["error", { "switches": "always" }]*/
switch (a) {
    case 0: foo();
}
if (a) {
    b();
}:::
Examples of incorrect code for this rule with the { "switches": "never" } option:
::: incorrect
/*eslint padded-blocks: ["error", { "switches": "never" }]*/
switch (a) {
    case 0: foo();
}:::
Examples of correct code for this rule with the { "switches": "never" } option:
::: correct
/*eslint padded-blocks: ["error", { "switches": "never" }]*/
switch (a) {
    case 0: foo();
}
if (a) {
    b();
}:::
always + allowSingleLineBlocks 
Examples of incorrect code for this rule with the "always", {"allowSingleLineBlocks": true} options:
::: incorrect
/*eslint padded-blocks: ["error", "always", { allowSingleLineBlocks: true }]*/
if (a) {
    b();
}
if (a) {
    b();
}
if (a) {
    b();
}:::
Examples of correct code for this rule with the "always", {"allowSingleLineBlocks": true} options:
::: correct
/*eslint padded-blocks: ["error", "always", { allowSingleLineBlocks: true }]*/
if (a) { b(); }
if (a) {
    b();
}:::
When Not To Use It 
You can turn this rule off if you are not concerned with the consistency of padding within blocks.