JS.TS.NO.UNNECESSARY.TYPE.ARGUMENTS

Enforces that type arguments will not be used if not required

Warns if an explicitly specified type argument is the default for that type parameter.

Rule Details

Type parameters in TypeScript may specify a default value. For example:

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function f<T = number>() {}

It is redundant to provide an explicit type parameter equal to that default.

Examples of code for this rule:

Incorrect

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function f<T = number>() {}
f<number>();

function g<T = number, U = string>() {}
g<string, string>();

class C<T = number> {}
function h(c: C<number>) {}
new C<number>();
class D extends C<number> {}

interface I<T = number> {}
class Impl implements I<number> {}

Correct

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function f<T = number>() {}
f<string>();

function g<T = number, U = string>() {}
g<number, number>();

class C<T = number> {}
new C<string>();
class D extends C<string> {}

interface I<T = number> {}
class Impl implements I<string> {}

Options

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// .eslintrc.json
{
  "rules": {
    "@typescript-eslint/no-unnecessary-type-arguments": "warn"
  }
}

This rule is not configurable.