Magento 2 graphql image upload using file

First convert your image into base64 then use that base64 string in to graphql input.

<?php

namespace Vendor\Module\Model\Upload;

use Magento\Framework\GraphQl\Config\Element\Field;
use Magento\Framework\GraphQl\Exception\GraphQlInputException;
use Magento\Framework\GraphQl\Query\ResolverInterface;
use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
use Magento\Framework\App\Filesystem\DirectoryList;
use Magento\Framework\Filesystem;
use Magento\Framework\Filesystem\Driver\File;

class UploadImage implements ResolverInterface
{
    public function __construct(
        Filesystem $fileSystem,
        File $fileDriver
    ) {
        $this->fileSystem = $fileSystem;
        $this->fileDriver = $fileDriver;
    }
    public function resolve(
        Field $field,
        $context,
        ResolveInfo $info,
        array $value = null,
        array $args = null
    ) {
        $this->uploadFile($fileData);
    }

    public function uploadFile($fileData)
    {
        $uploadedFileName = "";
        $fileName = '';
        if (isset($fileData['name'])) {
            $fileName = $fileData['name'];
        } else {
            $fileName = rand() . time();
        }
        if (isset($fileData['filecontent'])) {
            $mediaPath = $this->fileSystem->getDirectoryRead(DirectoryList::MEDIA)->getAbsolutePath();
            $originalPath = 'ModuleName/Attachments/';
            $mediaFullPath = $mediaPath . $originalPath;
            if (!file_exists($mediaFullPath)) {
                mkdir($mediaFullPath, 0775, true);
            }
            /* Check File is exist or not */
            $fullFilepath = $mediaFullPath . $fileName;
            if ($this->fileDriver->isExists($fullFilepath)) {
                $fileName = rand() . time() . $fileName;
            }
            $fileContent = base64_decode($fileData['filecontent']);
            $savedFile = fopen($mediaFullPath . $fileName, "wb");
            fwrite($savedFile, $fileContent);
            fclose($savedFile);
            $uploadedFileName = "/" . $fileName ;
        }
        return $uploadedFileName;
    }
}

And the VAR is :

$fileData is array 
$fileData['filecontent'] = base64 string of file.
$fileData['name'] = file name.

Using base64 is the best solution.

Other solution: You can also get file data using file_get_contents() PHP function. And store in new file using file_put_contents() PHP function. This function creates an issue when data is large. When we use in graphql query then it returns only file data as a response.

Reference link :

https://www.w3schools.com/php/func_filesystem_file_get_contents.asp

https://www.w3schools.com/php/func_filesystem_file_put_contents.asp

https://www.php.net/manual/en/function.file-put-contents.php

https://www.faqcode4u.com/faq/411274/php-image-file-upload-and-convert-to-base64-without-saving-image

I suggest going with base64 implementation

Step 1: Create the directory structure for your module: app/code/XTeam/ImageUpload

Step 2: Create the file app/code/XTeam/ImageUpload/etc/schema.graphqls with the following content:

type Mutation {
    xtUploadFiles(input: [ImageUploads!]): XTUploadOutput @resolver(class: "XTeam\\ImageUpload\\Model\\Resolver\\ImgUploadFiles") @doc(description:"Upload files to the pub/media static folder")
}

input ImageUploads {
    image_url: String @doc(description: "Base64 encoded image string")
    store_id: String @doc(description: "Store ID associated with the slider")
    status: String @doc(description: "Status of the slider")
}

type XTUploadOutput {
    items: [XTUploadedReturn]
}

type XTUploadedReturn {
    order_path: String @doc(description: "File Order path")
    message: String @doc(description: "Upload message")
}

Step 3: Create the file app/code/XTeam/ImageUpload/Model/Resolver/ImgUploadFiles.php with the following content:

<?php
declare(strict_types=1);

namespace XTeam\ImageUpload\Model\Resolver;

use Magento\Framework\App\Filesystem\DirectoryList;
use Magento\Framework\Exception\InputException;
use Magento\Framework\Filesystem;
use Magento\Framework\GraphQl\Config\Element\Field;
use Magento\Framework\GraphQl\Exception\GraphQlInputException;
use Magento\Framework\GraphQl\Query\ResolverInterface;
use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
use XTeam\Slider\Model\DataexampleFactory;

class ImgUploadFiles implements ResolverInterface
{
    private $_storeManager;
    private $fileSystem;
    private $dataExampleFactory;

    public function __construct(
        \Magento\Store\Model\StoreManagerInterface $storeManager,
        Filesystem $fileSystem,
        DataexampleFactory $dataExampleFactory
    ) {
        $this->_storeManager = $storeManager;
        $this->fileSystem = $fileSystem;
        $this->dataExampleFactory = $dataExampleFactory;
    }

    public function resolve(
        Field $field,
        $context,
        ResolveInfo $info,
        array $value = null,
        array $args = null
    ) {
        if (empty($args['input']) || !is_array($args['input'])) {
            throw new GraphQlInputException(__('You must specify your input.'));
        }

        try {
            $mediaUrl = $this->_storeManager->getStore()->getBaseUrl(\Magento\Framework\UrlInterface::URL_TYPE_MEDIA);
            $mediaPath = $this->fileSystem->getDirectoryRead(DirectoryList::MEDIA)->getAbsolutePath();
            $uploadPath = 'xteam/uploads/';
            $mediaFullPath = $mediaPath . $uploadPath;

            if (!file_exists($mediaFullPath)) {
                mkdir($mediaFullPath, 0775, true);
            }

            $response = ['items' => []];
            foreach ($args['input'] as $input) {
                $base64Data = explode(',', $input['image_url']);
                $fileContent = base64_decode(end($base64Data));

                if ($fileContent === false) {
                    throw new GraphQlInputException(__('Invalid base64 encoded image.'));
                }

                $fileName = uniqid() . '.jpg';
                $filePath = $mediaFullPath . $fileName;
                file_put_contents($filePath, $fileContent);

                $dataModel = $this->dataExampleFactory->create();
                $dataModel->setData([
                    'image_url' => $mediaUrl . $uploadPath . $fileName,
                    'store_id' => $input['store_id'],
                    'status' => $input['status']
                ])->save();

                $response['items'][] = [
                    'order_path' => $uploadPath . $fileName,
                    'message' => 'Image uploaded successfully.'
                ];
            }

            return $response;
        } catch (InputException $e) {
            throw new GraphQlInputException(__($e->getMessage()));
        }
    }
}

Step 4: Use the following GraphQL mutation:

mutation {
  xtUploadFiles(
    input: [
      {
        image_url: "data:image/jpeg;base64,[BASE64_ENCODED_IMAGE]",
        store_id: "1",
        status: "true"
      }
    ]
  ) {
    items {
      order_path
      message
    }
  }
}

Gives output like this:

{
  "data": {
    "xtUploadFiles": {
      "items": [
        {
          "order_path": "xteam/uploads/unique_file_name.jpg",
          "message": "Image uploaded successfully."
        }
      ]
    }
  }
}