useThrowNewError (JavaScript)

Language JavaScript (and super languages)

Summary

Rule available since: v1.8.0
Diagnostic Category: lint/style/useThrowNewError
This rule isn’t recommended, so you need to enable it.
This rule has an unsafe fix.
The default severity of this rule is information.
Sources:
- Same as unicorn/throw-new-error

How to configure

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

Description

Require new when throwing an error.

While it’s possible to instantiate Error without using the new keyword, it’s better to be consistent: modern builtins require new to be instantiated.

Rule matches errors when their name ends with the word “Error” and the first character is uppercase.

Examples

Invalid

1
throw Error();

code-block.js:1:7 lint/style/useThrowNewError  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Use new Error() instead of Error() when throwing an error.
  
  > 1 │ throw Error();
      │       ^^^^^^^
    2 │ 
  
  ℹ Instantiate Error with new keyword for consistency with modern builtins.
  
  ℹ Unsafe fix: Add new keyword.
  
    1 │ throw·new·Error();
      │       ++++

1
throw TypeError('biome');

code-block.js:1:7 lint/style/useThrowNewError  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Use new TypeError() instead of TypeError() when throwing an error.
  
  > 1 │ throw TypeError('biome');
      │       ^^^^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Instantiate Error with new keyword for consistency with modern builtins.
  
  ℹ Unsafe fix: Add new keyword.
  
    1 │ throw·new·TypeError('biome');
      │       ++++

1
throw lib.TypeError();

code-block.js:1:7 lint/style/useThrowNewError  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ℹ Use new TypeError() instead of TypeError() when throwing an error.
  
  > 1 │ throw lib.TypeError();
      │       ^^^^^^^^^^^^^^^
    2 │ 
  
  ℹ Instantiate Error with new keyword for consistency with modern builtins.
  
  ℹ Unsafe fix: Add new keyword.
  
    1 │ throw·new·lib.TypeError();
      │       ++++

Valid

1
throw new Error();

1
throw new TypeError('biome');

1
throw new lib.TypeError();