# Typescript style guide

## Use `type` rather than `interface` for named parameters and POJO return values.

`type` and `interface` can be used somewhat interchangeably, but let's use `type` to describe data and `interface` to describe (polymorphic) behaviour.

Good examples of data are option objects to have named parameters, and POJO (plain old javascript objects) without any methods, just fields.

Also see [this playground](https://www.typescriptlang.org/play?#code/C4TwDgpgBACghgJwgO2AeTMAlge2QZygF4oBvAKCiqmTgFsIAuKfYBLZAcwG5LqATCABs4IAPzNkAVzoAjCAl4BfcuVCQoAYQAWWIfwzY8hEvCSpDuAlABkZPlQDGOITgTNW7LstWOR+QjMUYHtqKGcCNilHYDcAChxMK3xmIIsk4wBKewcoFRVyPzgArV19KAgAD2AUfkDEYNDqCM9o2IQEjIJmHT0DLvxsijCw-ClIDsSjAkzeEebjEIYAuE5oEgADABJSKeSAOloGJSgsQh29433nVwQlDbnqfKA)

## Use `Record<string, any>` to describe a type that accepts any Javascript object.

Prefer this over index signature, `any` or `object`.