## File Upload Using GraphQL and Node.js

### Overview
This guide explains how to upload a file using a GraphQL mutation in a Node.js application. You will use the `graphql-request` library for making GraphQL requests and the `form-data` package to handle the file upload.

### Steps to Perform a File Upload

1. **Install Required Packages**  
First, install the necessary npm packages:

```shell
   npm install graphql-request form-data axios
   ```

2. **Set Up the GraphQL Mutation**  
Your GraphQL mutation should look like this:

```graphql
   mutation singleUpload($file: Upload!) {
        singleUpload(
          file: $file,
          entity_id: "your_entity_id", // or representative_id
          file_enum: front_drivers_license
        ) {
          filename
        }
   }
   ```

3. **Prepare the Upload Function**  
Create a Node.js script (`upload.js`) to handle the file upload:

```javascript
   const { GraphQLClient, gql } = require('graphql-request');
   const FormData = require('form-data');
   const fs = require('fs');
   const path = require('path');
   const axios = require('axios');

const ENDPOINT = 'https://your-graphql-endpoint.com/graphql';
   const TOKEN = 'your-access-token';
   const ENTITY_ID = 'your_entity_id'; // or representative_id

const query = gql`
        mutation singleUpload($file: Upload!) {
          singleUpload(
            file: $file,
            entity_id: "${ENTITY_ID}", // or representative_id
            file_enum: front_drivers_license
          ) {
            filename
          }
        }
   `;

async function uploadFile() {
         const form = new FormData();

const operations = JSON.stringify({
           query: `
             mutation singleUpload($file: Upload!) {
               singleUpload(
                 file: $file,
                 entity_id: "${ENTITY_ID}", // or representative_id
                 file_enum: front_drivers_license
               ) {
                 filename
               }
             }
           `,
           variables: {
             file: null
           }
         });

form.append('operations', operations);

const map = JSON.stringify({
           0: ['variables.file']
         });
         form.append('map', map);

const filePath = path.join(__dirname, 'my-fake-file.txt');
         form.append('0', fs.createReadStream(filePath), 'my-fake-file.txt');

try {
           const response = await axios.post(`${ENDPOINT}`, form, {
             headers: {
               ...form.getHeaders(),
               'apollo-require-preflight': true,
               Authorization: `Bearer ${TOKEN}`
             }
           });

console.log('File uploaded successfully:', response.data);
         } catch (error) {
           console.error('Error uploading file:', error);
         }
   }

uploadFile();
   ```

### Example Explanation  
- **Endpoint URL**: Replace `https://your-graphql-endpoint.com/graphql` with your actual GraphQL endpoint.  
- **Authorization Header**: Replace `your-access-token` with your actual token.  
- **File Path**: Replace `path.join(__dirname, 'my-fake-file.txt')` with the path to the file you want to upload.  
- **Entity ID**: Replace `your_entity_id` with the actual entity or representative ID required by your mutation.

### Example Script  
Here's a complete example script with placeholders replaced:

const ENDPOINT = 'https://api.example.com/graphql';
   const TOKEN = 'your-access-token';
   const ENTITY_ID = '12345'; // or representative_id

async function uploadFile() {
     const form = new FormData();

form.append('operations', operations);

const map = JSON.stringify({
       0: ['variables.file']
     });
     form.append('map', map);

const filePath = path.join(__dirname, 'my-fake-file.txt');
     form.append('0', fs.createReadStream(filePath), 'my-fake-file.txt');

console.log('File uploaded successfully:', response.data);
     } catch (error) {
       console.error('Error uploading file:', error);
     }
   }

uploadFile();
   ```

### Notes  
- Ensure the file path is correct and accessible.  
- The `Authorization` header must contain a valid token.  
- The `operations` and `map` parameters must be properly formatted JSON strings.

By following these steps, you can successfully upload a file using a GraphQL mutation with Node.js. If you encounter any issues, check the structure of your `operations` and `map` parameters, and ensure your file path is correct.