# functional/no-mixed-types 📝 Restrict types so that only members of the same kind are allowed in them. 💼 This rule is enabled in the following configs: ☑️ `lite`,  `noOtherParadigms`, ✅ `recommended`, 🔒 `strict`. 💭 This rule requires [type information](https://typescript-eslint.io/linting/typed-linting). This rule enforces that an aliased type literal or an interface only has one type of members, eg. only data properties or only functions. ## Rule Details Mixing functions and data properties in the same type is a sign of object-orientation style. ### ❌ Incorrect ```ts /* eslint functional/no-mixed-types: "error" */ type Foo = { prop1: string; prop2: () => string; }; ``` ### ✅ Correct ```ts /* eslint functional/no-mixed-types: "error" */ type Foo = { prop1: string; prop2: number; }; ``` ```ts /* eslint functional/no-mixed-types: "error" */ type Foo = { prop1: () => string; prop2(): number; }; ``` ## Limitations This rule will only check alias type literal declarations and interface declarations. Advanced types will not be checked. For example union and intersection types will not be checked. ## Options This rule accepts an options object of the following type: ```ts type Options = { checkInterfaces: boolean; checkTypeLiterals: boolean; }; ``` ### Default Options ```ts const defaults = { checkInterfaces: true, checkTypeLiterals: true, }; ``` ### checkInterfaces If true, interface declarations will be checked. ### checkTypeLiterals If true, aliased type literal declarations will be checked.