### Installing supertest-graphql with npm

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Command to install the supertest-graphql package using npm. This is the first step to use the library in your project.

```Shell
npm install supertest-graphql
```

--------------------------------

### Testing GraphQL Mutation with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Illustrates how to test a GraphQL mutation using the `.mutate()` method. Similar to queries, variables can be passed using `.variables()`. It shows an example of a `PetAnimal` mutation.

```TypeScript
const { data } = await request(app)
  .mutate(gql`
    mutation PetAnimal($petId: ID!) {
      petAnimal(petId: $petId) {
        name
        petType
      }
    }
  `)
  .variables({petId: 'my-cat' })
```

--------------------------------

### Testing GraphQL Subscriptions with supertest-graphql WebSockets

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Demonstrates testing GraphQL subscriptions over WebSockets using `supertestWs`. It shows how to set up the server for WebSocket tests, subscribe to an event, wait for the next value, and assert the response.

```TypeScript
import { supertestWs } from 'supertest-graphql'
import gql from 'graphql-tag'

// for websocket the server needs to be started and stopped manually
beForeEach(() => server.listen(0, "localhost"))
afterEach(() => server.close())

test('should get pets', async () => {
  const sub = await supertestWs(app)
    .subscribe(gql`
      subscription {
        newPetAdded {
          name
          petType
        }
      }
    `)
  
  // will wait or pop the next value
  const { data } = await sub.next().expectNoErrors()

  expect(data.newPetAdded.name).toEqual('Fifi')
})
```

--------------------------------

### Using WebSocket Legacy Protocol with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Demonstrates how to explicitly set the WebSocket protocol to the legacy version using `.protocol()` and the `LEGACY_WEBSOCKET_PROTOCOL` constant.

```TypeScript
import { supertestWs, LEGACY_WEBSOCKET_PROTOCOL } from 'supertest-graphql'

const sub = await supertestWs(app)
  .protocol(LEGACY_WEBSOCKET_PROTOCOL)
  .subscribe(...)
```

--------------------------------

### Adding Authentication to GraphQL Requests with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Shows how to add basic authentication credentials to a GraphQL request using the `.auth()` method provided by supertest.

```TypeScript
const { data } = await request(app)
  .auth('username', 'password')
  .query(...)
```

--------------------------------

### Testing GraphQL Query with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Demonstrates a basic test case using supertest-graphql to send a GraphQL query, assert no errors, and check the response data. It uses `request` to wrap the app and `gql` for parsing the query string.

```TypeScript
import request from 'supertest-graphql'
import gql from 'graphql-tag'

test('should get pets', async () => {
  const { data } = await request(app)
    .query(gql`
      query {
        pets {
          name
          petType
        }
      }
    `)
    .expectNoErrors()
  
  expect(data.pets).toHaveLength(2)
})
```

--------------------------------

### Adding Authentication to WebSocket Subscriptions with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Explains how to pass authentication parameters during the WebSocket connection handshake for subscriptions using the `.connectionParams()` method with `supertestWs`.

```TypeScript
import { supertestWs } from 'supertest-graphql'

const sub = await supertestWs(app)
  .connectionParams({
    token: 'my token'
  })
  .subscribe(...)
```

--------------------------------

### Adding Authentication Headers to GraphQL Requests with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Demonstrates how to add custom headers, such as an Authorization token, to a GraphQL request using the standard supertest `.set()` method.

```TypeScript
const { data } = await request(app)
  .set('authorization', 'my token')
  .query(...)
```

--------------------------------

### Changing GraphQL Endpoint Path with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Shows how to specify a different endpoint path for GraphQL requests using the `.path()` method, overriding the default `/graphql`.

```TypeScript
const { data } = await request(app)
  .path('/new-graphql')
  .query(...)
```

--------------------------------

### Passing Variables to GraphQL Query with supertest-graphql

Source: https://github.com/alexstrat/supertest-graphql/blob/master/README.md

Shows how to pass variables to a parameterized GraphQL query using the `.variables()` method. The variables object keys should match the variable names defined in the query.

```TypeScript
const { data } = await request(app)
  .query(gql`
    query GetPets($first: Int){
      pets(first: $first) {
        name
        petType
      }
    }
  `)
  .variables({ first: 4 })
```

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