---
source: crates/biome_js_analyze/tests/spec_tests.rs
expression: invalid.js
---
# Input
```jsx
if (Boolean(foo)) {
}

if (!!Boolean(foo)) {
}

if (!Boolean(foo)) {
}

while (!!foo) {}

let x = 1;
do {
	1 + 1;
} while (Boolean(x));

for (; !!foo; ) {}

new Boolean(!!x);

!!!x;

!Boolean(x);
```

# Diagnostics
```
invalid.js:1:5 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant `Boolean` call
  
  > 1 │ if (Boolean(foo)) {
      │     ^^^^^^^^^^^^
    2 │ }
    3 │ 
  
  i It is not necessary to use `Boolean` call when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant `Boolean` call
  
    1 │ if·(Boolean(foo))·{
      │     --------   -   

```

```
invalid.js:4:5 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant double-negation.
  
    2 │ }
    3 │ 
  > 4 │ if (!!Boolean(foo)) {
      │     ^^^^^^^^^^^^^^
    5 │ }
    6 │ 
  
  i It is not necessary to use double-negation when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant double-negation
  
    4 │ if·(!!Boolean(foo))·{
      │     --               

```

```
invalid.js:4:7 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant `Boolean` call
  
    2 │ }
    3 │ 
  > 4 │ if (!!Boolean(foo)) {
      │       ^^^^^^^^^^^^
    5 │ }
    6 │ 
  
  i It is not necessary to use `Boolean` call when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant `Boolean` call
  
    4 │ if·(!!Boolean(foo))·{
      │       --------   -   

```

```
invalid.js:7:6 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant `Boolean` call
  
    5 │ }
    6 │ 
  > 7 │ if (!Boolean(foo)) {
      │      ^^^^^^^^^^^^
    8 │ }
    9 │ 
  
  i It is not necessary to use `Boolean` call when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant `Boolean` call
  
    7 │ if·(!Boolean(foo))·{
      │      --------   -   

```

```
invalid.js:10:8 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant double-negation.
  
     8 │ }
     9 │ 
  > 10 │ while (!!foo) {}
       │        ^^^^^
    11 │ 
    12 │ let x = 1;
  
  i It is not necessary to use double-negation when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant double-negation
  
    10 │ while·(!!foo)·{}
       │        --       

```

```
invalid.js:15:10 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant `Boolean` call
  
    13 │ do {
    14 │ 	1 + 1;
  > 15 │ } while (Boolean(x));
       │          ^^^^^^^^^^
    16 │ 
    17 │ for (; !!foo; ) {}
  
  i It is not necessary to use `Boolean` call when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant `Boolean` call
  
    15 │ }·while·(Boolean(x));
       │          -------- -  

```

```
invalid.js:17:8 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant double-negation.
  
    15 │ } while (Boolean(x));
    16 │ 
  > 17 │ for (; !!foo; ) {}
       │        ^^^^^
    18 │ 
    19 │ new Boolean(!!x);
  
  i It is not necessary to use double-negation when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant double-negation
  
    17 │ for·(;·!!foo;·)·{}
       │        --         

```

```
invalid.js:19:13 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant double-negation.
  
    17 │ for (; !!foo; ) {}
    18 │ 
  > 19 │ new Boolean(!!x);
       │             ^^^
    20 │ 
    21 │ !!!x;
  
  i It is not necessary to use double-negation when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant double-negation
  
    19 │ new·Boolean(!!x);
       │             --   

```

```
invalid.js:21:2 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant double-negation.
  
    19 │ new Boolean(!!x);
    20 │ 
  > 21 │ !!!x;
       │  ^^^
    22 │ 
    23 │ !Boolean(x);
  
  i It is not necessary to use double-negation when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant double-negation
  
    21 │ !!!x;
       │  --  

```

```
invalid.js:23:2 lint/complexity/noExtraBooleanCast  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Avoid redundant `Boolean` call
  
    21 │ !!!x;
    22 │ 
  > 23 │ !Boolean(x);
       │  ^^^^^^^^^^
  
  i It is not necessary to use `Boolean` call when a value will already be coerced to a boolean.
  
  i Unsafe fix: Remove redundant `Boolean` call
  
    23 │ !Boolean(x);
       │  -------- - 

```