Simple GraphQL Client for web browser

graphql_query.js

function graphql_query(endpoint, query, variables = {}, token = null) {
  return new Promise((resolve, reject) => {
    const headers = {
      'Content-Type': 'application/json',
    }

    if (token) {
      headers['Authorization'] = `Bearer ${token}`
    }

    fetch(endpoint, {
      method: 'post',
      headers,
      body: JSON.stringify({
        query,
        variables,
      }),
    })
    .then(response => response.json())
    .then(json => resolve(json))
    .catch(e => reject(e))
  })
}

index.html

<!-- Usage example -->

<script src="graphql_query.js"></script>
<script>
  const query = `query {
    posts {
      data {
        id
        title
      }
    }
  }`;

  graphql_query('https://graphqlzero.almansi.me/api', query)
    .then(response => {
      console.log(response)
    })
</script>