# Install
```
$ npm i @darkobits/interop-import-default
```
# Use
This function is intended to gracefully address issues with the default exports of packages that may
have been transpiled/bundled improperly or were simply transpiled to run in an environment that has
built-in support for addressing this kind of issue.
This problem can often rear its head when working in mixed CJS / ESM environments.
### Before / Ideal:
```ts
import wonky from 'wonky';
// Use `wonky` as the developer intended.
```
Sometimes, based on the Node version running this code and how the code was transpiled/bundled, a
package's default export may be on a property key `default` on the value imported.
### Naive TypeScript Fix:
```ts
import wonkyExport from 'wonky';
const wonky = wonkyExport.default;
// Now, typeof wonky is incorrect; IntelliSense is broken, and
// TypeScript will throw errors.
```
Furthermore, you may run into cases where your code behaves differently in different runtime
environments, especially if you are authoring a library and you don't know how your code will be
transpiled by the end user. Some bundlers have built-in interop features that address this issue, but
running the same code in Node will produce an error.
Even worse, TypeScript can miss this error at compile-time, mistakenly thinking that the default
export of a package is the value we expected it to be rather than an object with a nested `default`
property.
This function is designed to be used as a **runtime dependency** that will address both of these\
problems. First, it ensures your code runs the same way in both types of environments by returning the
provided value as-is if it doesn't contain a `default` key. Second, it type-casts the return value as
the type of the parameter provided, so TypeScript will always be happy. 🌈
```ts
import wonkyExport from 'wonky';
import { interopImportDefault } from '@darkobits/interop-import-default';
const wonky = interopImportDefault(wonkyExport);
// Use `wonky` as the developer intended.
```
---
_Source: https://npm.io/package/@darkobits/interop-import-default · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._
---
_Source: https://npm.io/package/@darkobits/interop-import-default · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._