noEmptyTypeParameters

TypeScript and TSX

Summary

Rule available since: v1.5.0
Diagnostic Category: lint/complexity/noEmptyTypeParameters
This rule is recommended, which means is enabled by default.
This rule doesn’t have a fix.
The default severity of this rule is error.

Description

Disallow empty type parameters in type aliases and interfaces.

TypeScript permits the use of empty type parameter lists in type alias and interface declarations; however, this practice is generally discouraged. Allowing empty type parameter lists can lead to unclear or ambiguous code, where the intention of the generic type is not self-evident. This rule disallows empty type parameter lists in type alias and interface declarations.

Examples

Invalid

1
interface Foo<> {}

code-block.ts:1:14 lint/complexity/noEmptyTypeParameters ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Using an empty type parameter list is confusing.
  
  > 1 │ interface Foo<> {}
      │              ^^
    2 │ 
  
  ℹ Remove the empty type parameter list or add a type parameter.

1
type Bar<> = {};

code-block.ts:1:9 lint/complexity/noEmptyTypeParameters ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ Using an empty type parameter list is confusing.
  
  > 1 │ type Bar<> = {};
      │         ^^
    2 │ 
  
  ℹ Remove the empty type parameter list or add a type parameter.

Valid

1
interface Foo {}

1
type Foo<T> = {
2
 bar: T;
3
}

How to configure

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