An empty interface in TypeScript does very little: any non-nullable value is assignable to{}.Using an empty interface is often a sign of programmer error, such as misunderstanding the concept of{} or forgetting to fill in fields.

This rule aims to ensure that only meaningful interfaces are declared in the code.

exportdefault tseslint.config({
rules:{
"@typescript-eslint/no-empty-interface":"error"
}
});

module.exports={
"rules":{
"@typescript-eslint/no-empty-interface":"error"
}
};

Examples​

// an empty interface
interfaceFoo{}

// an interface with only one supertype (Bar === Foo)
interfaceBarextendsFoo{}

// an interface with an empty list of supertypes
interfaceBaz{}

// an interface with any number of members
interfaceFoo{
  name:string;
}

// same as above
interfaceBar{
  age:number;
}

// an interface with more than one supertype
// in this case the interface can be used as a replacement of an intersection type.
interfaceBazextendsFoo, Bar{}

Options​

This rule accepts the following options:

typeOptions=[
{
/** Whether to allow empty interfaces that extend a single other interface. */
    allowSingleExtends?:boolean;
},
];

const defaultOptions: Options=[{ allowSingleExtends:false}];

allowSingleExtends​

Whether to allow empty interfaces that extend a single other interface. Default: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.

Related To​

• no-empty-object-type

Resources​

• Rule source
• Test source