---
source: crates/biome_js_analyze/tests/spec_tests.rs
expression: invalid.js
---
# Input
```jsx
var regex = RegExp("\\x1f");
var regex = RegExp("\\u{1111}*\\x1F", "u");
var regex = new RegExp("\\x1f\\x1e");
var regex = new RegExp("\\x1fFOO\\x00");
var regex = new RegExp("FOO\\x1fFOO\\x1f");
var regex = new RegExp("\\x1f");
var regex = new RegExp("\\u001F", flags);
var regex = new RegExp("\\u{1111}*\\x1F", "u");
var regex = new RegExp("\\u{1F}", "u");
var regex = new RegExp("\\u{1F}", "gui");
var regex = new RegExp("\\x0C");
var regex = new RegExp("\x0C");
var regex = /\x00/;
var regex = /\x0C/;
var regex = /\x1F/;
var regex = /\u000C/;
var regex = /\u{C}/u;
var regex = /\\\x1f\\x1e/;
var regex = /\\\x1fFOO\\x00/;
var regex = /FOO\\\x1fFOO\\x1f/;
var regex = /(?<a>\\x1f)/;
var regex = /(?<\u{1d49c}>.)\x1f/;
var regex = /\u{1111}*\x1F/u;
var regex = /\u{1F}/u;
var regex = /\u{1F}/gui;

```

# Diagnostics
```
invalid.js:1:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f
  
  > 1 │ var regex = RegExp("\\x1f");
      │             ^^^^^^^^^^^^^^^
    2 │ var regex = RegExp("\\u{1111}*\\x1F", "u");
    3 │ var regex = new RegExp("\\x1f\\x1e");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:2:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1F
  
    1 │ var regex = RegExp("\\x1f");
  > 2 │ var regex = RegExp("\\u{1111}*\\x1F", "u");
      │             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    3 │ var regex = new RegExp("\\x1f\\x1e");
    4 │ var regex = new RegExp("\\x1fFOO\\x00");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:3:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f, \x1e
  
    1 │ var regex = RegExp("\\x1f");
    2 │ var regex = RegExp("\\u{1111}*\\x1F", "u");
  > 3 │ var regex = new RegExp("\\x1f\\x1e");
      │             ^^^^^^^^^^^^^^^^^^^^^^^^
    4 │ var regex = new RegExp("\\x1fFOO\\x00");
    5 │ var regex = new RegExp("FOO\\x1fFOO\\x1f");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:4:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f, \x00
  
    2 │ var regex = RegExp("\\u{1111}*\\x1F", "u");
    3 │ var regex = new RegExp("\\x1f\\x1e");
  > 4 │ var regex = new RegExp("\\x1fFOO\\x00");
      │             ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    5 │ var regex = new RegExp("FOO\\x1fFOO\\x1f");
    6 │ var regex = new RegExp("\\x1f");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:5:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f, \x1f
  
    3 │ var regex = new RegExp("\\x1f\\x1e");
    4 │ var regex = new RegExp("\\x1fFOO\\x00");
  > 5 │ var regex = new RegExp("FOO\\x1fFOO\\x1f");
      │             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    6 │ var regex = new RegExp("\\x1f");
    7 │ var regex = new RegExp("\\u001F", flags);
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:6:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f
  
    4 │ var regex = new RegExp("\\x1fFOO\\x00");
    5 │ var regex = new RegExp("FOO\\x1fFOO\\x1f");
  > 6 │ var regex = new RegExp("\\x1f");
      │             ^^^^^^^^^^^^^^^^^^^
    7 │ var regex = new RegExp("\\u001F", flags);
    8 │ var regex = new RegExp("\\u{1111}*\\x1F", "u");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:7:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \u001F
  
    5 │ var regex = new RegExp("FOO\\x1fFOO\\x1f");
    6 │ var regex = new RegExp("\\x1f");
  > 7 │ var regex = new RegExp("\\u001F", flags);
      │             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    8 │ var regex = new RegExp("\\u{1111}*\\x1F", "u");
    9 │ var regex = new RegExp("\\u{1F}", "u");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:8:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1F
  
     6 │ var regex = new RegExp("\\x1f");
     7 │ var regex = new RegExp("\\u001F", flags);
   > 8 │ var regex = new RegExp("\\u{1111}*\\x1F", "u");
       │             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     9 │ var regex = new RegExp("\\u{1F}", "u");
    10 │ var regex = new RegExp("\\u{1F}", "gui");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:9:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \u{1F}
  
     7 │ var regex = new RegExp("\\u001F", flags);
     8 │ var regex = new RegExp("\\u{1111}*\\x1F", "u");
   > 9 │ var regex = new RegExp("\\u{1F}", "u");
       │             ^^^^^^^^^^^^^^^^^^^^^^^^^^
    10 │ var regex = new RegExp("\\u{1F}", "gui");
    11 │ var regex = new RegExp("\\x0C");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:10:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \u{1F}
  
     8 │ var regex = new RegExp("\\u{1111}*\\x1F", "u");
     9 │ var regex = new RegExp("\\u{1F}", "u");
  > 10 │ var regex = new RegExp("\\u{1F}", "gui");
       │             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    11 │ var regex = new RegExp("\\x0C");
    12 │ var regex = new RegExp("\x0C");
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:11:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x0C
  
     9 │ var regex = new RegExp("\\u{1F}", "u");
    10 │ var regex = new RegExp("\\u{1F}", "gui");
  > 11 │ var regex = new RegExp("\\x0C");
       │             ^^^^^^^^^^^^^^^^^^^
    12 │ var regex = new RegExp("\x0C");
    13 │ var regex = /\x00/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:12:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x0C
  
    10 │ var regex = new RegExp("\\u{1F}", "gui");
    11 │ var regex = new RegExp("\\x0C");
  > 12 │ var regex = new RegExp("\x0C");
       │             ^^^^^^^^^^^^^^^^^^
    13 │ var regex = /\x00/;
    14 │ var regex = /\x0C/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:13:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x00
  
    11 │ var regex = new RegExp("\\x0C");
    12 │ var regex = new RegExp("\x0C");
  > 13 │ var regex = /\x00/;
       │             ^^^^^^
    14 │ var regex = /\x0C/;
    15 │ var regex = /\x1F/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:14:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x0C
  
    12 │ var regex = new RegExp("\x0C");
    13 │ var regex = /\x00/;
  > 14 │ var regex = /\x0C/;
       │             ^^^^^^
    15 │ var regex = /\x1F/;
    16 │ var regex = /\u000C/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:15:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1F
  
    13 │ var regex = /\x00/;
    14 │ var regex = /\x0C/;
  > 15 │ var regex = /\x1F/;
       │             ^^^^^^
    16 │ var regex = /\u000C/;
    17 │ var regex = /\u{C}/u;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:16:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \u000C
  
    14 │ var regex = /\x0C/;
    15 │ var regex = /\x1F/;
  > 16 │ var regex = /\u000C/;
       │             ^^^^^^^^
    17 │ var regex = /\u{C}/u;
    18 │ var regex = /\\\x1f\\x1e/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:17:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \u{C}
  
    15 │ var regex = /\x1F/;
    16 │ var regex = /\u000C/;
  > 17 │ var regex = /\u{C}/u;
       │             ^^^^^^^^
    18 │ var regex = /\\\x1f\\x1e/;
    19 │ var regex = /\\\x1fFOO\\x00/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:18:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f
  
    16 │ var regex = /\u000C/;
    17 │ var regex = /\u{C}/u;
  > 18 │ var regex = /\\\x1f\\x1e/;
       │             ^^^^^^^^^^^^^
    19 │ var regex = /\\\x1fFOO\\x00/;
    20 │ var regex = /FOO\\\x1fFOO\\x1f/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:19:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f
  
    17 │ var regex = /\u{C}/u;
    18 │ var regex = /\\\x1f\\x1e/;
  > 19 │ var regex = /\\\x1fFOO\\x00/;
       │             ^^^^^^^^^^^^^^^^
    20 │ var regex = /FOO\\\x1fFOO\\x1f/;
    21 │ var regex = /(?<a>\\x1f)/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:20:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f
  
    18 │ var regex = /\\\x1f\\x1e/;
    19 │ var regex = /\\\x1fFOO\\x00/;
  > 20 │ var regex = /FOO\\\x1fFOO\\x1f/;
       │             ^^^^^^^^^^^^^^^^^^^
    21 │ var regex = /(?<a>\\x1f)/;
    22 │ var regex = /(?<\u{1d49c}>.)\x1f/;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:22:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1f
  
    20 │ var regex = /FOO\\\x1fFOO\\x1f/;
    21 │ var regex = /(?<a>\\x1f)/;
  > 22 │ var regex = /(?<\u{1d49c}>.)\x1f/;
       │             ^^^^^^^^^^^^^^^^^^^^^
    23 │ var regex = /\u{1111}*\x1F/u;
    24 │ var regex = /\u{1F}/u;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:23:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \x1F
  
    21 │ var regex = /(?<a>\\x1f)/;
    22 │ var regex = /(?<\u{1d49c}>.)\x1f/;
  > 23 │ var regex = /\u{1111}*\x1F/u;
       │             ^^^^^^^^^^^^^^^^
    24 │ var regex = /\u{1F}/u;
    25 │ var regex = /\u{1F}/gui;
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:24:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \u{1F}
  
    22 │ var regex = /(?<\u{1d49c}>.)\x1f/;
    23 │ var regex = /\u{1111}*\x1F/u;
  > 24 │ var regex = /\u{1F}/u;
       │             ^^^^^^^^^
    25 │ var regex = /\u{1F}/gui;
    26 │ 
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```

```
invalid.js:25:13 lint/suspicious/noControlCharactersInRegex ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ! Unexpected control character(s) in regular expression: \u{1F}
  
    23 │ var regex = /\u{1111}*\x1F/u;
    24 │ var regex = /\u{1F}/u;
  > 25 │ var regex = /\u{1F}/gui;
       │             ^^^^^^^^^^^
    26 │ 
  
  i Control characters are unusual and potentially incorrect inputs, so they are disallowed.
  

```