Fix

Signed-off-by: Мария Малыгина <m.malygina@yadro.com>

internal/s3/client.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"crypto/sha256"
 	"encoding/hex"
+	"fmt"
 	"strconv"
 	"time"
 
@@ -71,6 +72,8 @@ func (c *Client) Put(bucket, key string, payload goja.ArrayBuffer) PutResponse {
 	return PutResponse{Success: true}
 }
 
+const multipartUploadMinPartSize = 5 * 1024 * 1024 // 5MB
+
 func (c *Client) Multipart(bucket, key string, objPartSize int, payload goja.ArrayBuffer, concurrency int) PutResponse {
    if objPartSize < multipartUploadMinPartSize {
 		stats.Report(c.vu, objPutFails, 1)
@@ -78,10 +81,10 @@ func (c *Client) Multipart(bucket, key string, objPartSize int, payload goja.Arr
 	}
 	start := time.Now()
 	uploader := manager.NewUploader(c.cli, func(u *manager.Uploader) {
-	    u.PartSize = objPartSize
-	    uploader.Concurrency = concurrency
+	    u.PartSize = int64(objPartSize)
+	    u.Concurrency = concurrency
     })
-	result, err := uploader.Upload(context.TODO(), &s3.PutObjectInput{
+	_, err := uploader.Upload(context.TODO(), &s3.PutObjectInput{
 	    Bucket: aws.String(bucket),
 	    Key:    aws.String(key),
 	    Body:   bytes.NewReader(payload.Bytes()),