---
source: crates/biome_js_analyze/tests/spec_tests.rs
expression: invalid.js
---
# Input
```jsx
var x, y

function test() {
	// Comment
	let foo, bar;
}

var x = 1,
	// comment
    y = 2

let
	a = 0,
	b = 1;

let // comment
	c = 0, // trailing comment
	/*0*/d;

while(true) var v = 0, u = 1;

```

# Diagnostics
```
invalid.js:1:1 lint/style/useSingleVarDeclarator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Declare variables separately
  
  > 1 │ var x, y
      │ ^^^^^^^^
    2 │ 
    3 │ function test() {
  
  i Unsafe fix: Break out into multiple declarations
  
     1    │ - var·x,·y
        1 │ + var·x
        2 │ + var·y
     2  3 │   
     3  4 │   function test() {
  

```

```
invalid.js:5:2 lint/style/useSingleVarDeclarator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Declare variables separately
  
    3 │ function test() {
    4 │ 	// Comment
  > 5 │ 	let foo, bar;
      │ 	^^^^^^^^^^^^^
    6 │ }
    7 │ 
  
  i Unsafe fix: Break out into multiple declarations
  
     3  3 │   function test() {
     4  4 │   	// Comment
     5    │ - → let·foo,·bar;
        5 │ + → let·foo;
        6 │ + → let·bar;
     6  7 │   }
     7  8 │   
  

```

```
invalid.js:8:1 lint/style/useSingleVarDeclarator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Declare variables separately
  
     6 │ }
     7 │ 
   > 8 │ var x = 1,
       │ ^^^^^^^^^^
   > 9 │ 	// comment
  > 10 │     y = 2
       │     ^^^^^
    11 │ 
    12 │ let
  
  i Unsafe fix: Break out into multiple declarations
  
     6  6 │   }
     7  7 │   
     8    │ - var·x·=·1,
     9    │ - → //·comment
    10    │ - ····y·=·2
        8 │ + var·x·=·1
        9 │ + //·comment
       10 │ + var·y·=·2
    11 11 │   
    12 12 │   let
  

```

```
invalid.js:12:1 lint/style/useSingleVarDeclarator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Declare variables separately
  
    10 │     y = 2
    11 │ 
  > 12 │ let
       │ ^^^
  > 13 │ 	a = 0,
  > 14 │ 	b = 1;
       │ 	^^^^^^
    15 │ 
    16 │ let // comment
  
  i Unsafe fix: Break out into multiple declarations
  
    10 10 │       y = 2
    11 11 │   
    12    │ - let
    13    │ - → a·=·0,
    14    │ - → b·=·1;
       12 │ + let·a·=·0;
       13 │ + let·b·=·1;
    15 14 │   
    16 15 │   let // comment
  

```

```
invalid.js:16:1 lint/style/useSingleVarDeclarator  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Declare variables separately
  
    14 │ 	b = 1;
    15 │ 
  > 16 │ let // comment
       │ ^^^^^^^^^^^^^^
  > 17 │ 	c = 0, // trailing comment
  > 18 │ 	/*0*/d;
       │ 	^^^^^^^
    19 │ 
    20 │ while(true) var v = 0, u = 1;
  
  i Unsafe fix: Break out into multiple declarations
  
    12 12 │   let
    13 13 │   	a = 0,
    14    │ - → b·=·1;
    15    │ - 
    16    │ - let·//·comment
    17    │ - → c·=·0,·//·trailing·comment
    18    │ - → /*0*/d;
       14 │ + → b·=·1;//·comment
       15 │ + 
       16 │ + let·c·=·0;·//·trailing·comment
       17 │ + /*0*/
       18 │ + let·d;
    19 19 │   
    20 20 │   while(true) var v = 0, u = 1;
  

```

```
invalid.js:20:13 lint/style/useSingleVarDeclarator ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Declare variables separately
  
    18 │ 	/*0*/d;
    19 │ 
  > 20 │ while(true) var v = 0, u = 1;
       │             ^^^^^^^^^^^^^^^^^
    21 │ 
  

```