noEmptyTypeParameters

Diagnostic Category: lint/complexity/noEmptyTypeParameters

TypeScript and TSX

Since: v1.5.0

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

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.

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

interface Foo {}

type Foo<T> = {
 bar: T;
}

How to configure

{
  "linter": {
    "rules": {
      "complexity": {
        "noEmptyTypeParameters": "error"
      }
    }
  }
}