no-empty-interface
Disallow the declaration of empty interfaces.
An empty interface is equivalent to its supertype. If the interface does not implement a supertype, then
the interface is equivalent to an empty object ({}
). In both cases it can be omitted.
Attributes
- Included in configs
- ✅ Recommended
- 🔒 Strict
- Fixable
- 🔧 Automated Fixer
- 💡 Suggestion Fixer
- 💭 Requires type information
Rule Details
This rule aims to ensure that only meaningful interfaces are declared in the code.
- ❌ Incorrect
- ✅ Correct
// an empty interface
interface Foo {}
// an interface with only one supertype (Bar === Foo)
interface Bar extends Foo {}
// an interface with an empty list of supertypes
interface Baz {}
// an interface with any number of members
interface Foo {
name: string;
}
// same as above
interface Bar {
age: number;
}
// an interface with more than one supertype
// in this case the interface can be used as a replacement of a union type.
interface Baz extends Foo, Bar {}
Options
This rule accepts a single object option with the following default configuration:
{
"@typescript-eslint/no-empty-interface": [
"error",
{
"allowSingleExtends": false
}
]
}
allowSingleExtends: true
will silence warnings about extending a single interface without adding additional members
When Not To Use It
If you don't care about having empty/meaningless interfaces, then you will not need this rule.