useBlockStatements

JavaScript (and super languages)

Summary

Rule available since: v1.0.0
Diagnostic Category: lint/style/useBlockStatements
This rule has an unsafe fix.
The default severity of this rule is information.
Sources:
- Same as curly

Description

Requires following curly brace conventions.

JavaScript allows the omission of curly braces when a block contains only one statement. However, it is considered by many to be best practice to never omit curly braces around blocks, even when they are optional, because it can lead to bugs and reduces code clarity.

Examples

Invalid

1
 if (x) x;

code-block.js:1:2 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
  > 1 │  if (x) x;
      │  ^^^^^^^^^
    2 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    1 │ ·if·(x)·{·x;·}
      │         ++  ++

1
 if (x) {
2
   x;
3
 } else y;

code-block.js:3:4 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
    1 │  if (x) {
    2 │    x;
  > 3 │  } else y;
      │    ^^^^^^^
    4 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    3 │ ·}·else·{·y;·}
      │         ++  ++

1
if (x) {
2
  x;
3
} else if (y) y;

code-block.js:3:8 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
    1 │ if (x) {
    2 │   x;
  > 3 │ } else if (y) y;
      │        ^^^^^^^^^
    4 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    3 │ }·else·if·(y)·{·y;·}
      │               ++  ++

1
   for (;;);

code-block.js:1:4 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
  > 1 │    for (;;);
      │    ^^^^^^^^^
    2 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    1   │ - ···for·(;;);
      1 │ + ···for·(;;)·{}
    2 2 │

1
   for (p in obj);

code-block.js:1:4 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
  > 1 │    for (p in obj);
      │    ^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    1   │ - ···for·(p·in·obj);
      1 │ + ···for·(p·in·obj)·{}
    2 2 │

1
  for (x of xs);

code-block.js:1:3 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
  > 1 │   for (x of xs);
      │   ^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    1   │ - ··for·(x·of·xs);
      1 │ + ··for·(x·of·xs)·{}
    2 2 │

1
  do;
2
  while (x);

code-block.js:1:3 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
  > 1 │   do;
      │   ^^^
  > 2 │   while (x);
      │   ^^^^^^^^^^
    3 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    1   │ - ··do;
      1 │ + ··do·{}
    2 2 │     while (x);
    3 3 │

1
   while (x);

code-block.js:1:4 lint/style/useBlockStatements  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Block statements are preferred in this position.
  
  > 1 │    while (x);
      │    ^^^^^^^^^^
    2 │ 
  
  ℹ Unsafe fix: Wrap the statement with a JsBlockStatement
  
    1   │ - ···while·(x);
      1 │ + ···while·(x)·{}
    2 2 │

1
  with (x);

code-block.js:1:3 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ with statements are not allowed in strict mode
  
  > 1 │   with (x);
      │   ^^^^^^^^^
    2 │

How to configure

1
{
2
  "linter": {
3
    "rules": {
4
      "style": {
5
        "useBlockStatements": "error"
6
      }
7
    }
8
  }
9
}