## `@envelop/graphql-middleware`

This plugins wraps [`graphql-middleware`](https://github.com/maticzav/graphql-middleware) and allow
you to apply schema middlewares that uses the standard defined by `graphql-middleware`.

> You can find an awesome
> [list of middlewares here](https://github.com/maticzav/graphql-middleware#awesome-middlewares-)

## Getting Started

```
yarn add graphql-middleware @envelop/graphql-middleware
```

## Usage Example

You can use any type of middleware defined for `graphql-middleware`, here's an example for doing
that with [`graphql-shield`](https://github.com/maticzav/graphql-shield):

```ts
import { execute, parse, specifiedRules, subscribe, validate } from 'graphql'
import { and, not, or, rule, shield } from 'graphql-shield'
import { envelop, useEngine } from '@envelop/core'
import { useGraphQLMiddleware } from '@envelop/graphql-middleware'

// ...
// You can find a complete example here: https://github.com/maticzav/graphql-shield#graphql-yoga
// ...

const permissions = shield({
  Query: {
    fruits: and(isAuthenticated, or(isAdmin, isEditor))
  },
  Mutation: {
    addFruitToBasket: isAuthenticated
  },
  Fruit: isAuthenticated,
  Customer: isAdmin
})

const getEnveloped = envelop({
  plugins: [
    useEngine({ parse, validate, specifiedRules, execute, subscribe }),
    // ... other plugins ...
    useSchema(mySchema),
    useGraphQLMiddleware([permissions])
  ]
})
```