Update S3 upload functions to use MIME type detection based on file content instead of name

s3/s3.go

@@ -5,9 +5,9 @@ import (
 	"context"
 	"encoding/binary"
 	"fmt"
+	"net/http"
 	"net/url"
 	"os"
-	"path"
 	"strings"
 	"time"
 
@@ -142,7 +142,7 @@ func (s ClientWithHelpers) Upload(data []byte, bucket, fileName string, metadata
 		return nil, ErrorS3ClientNotEstablished
 	}
 
-	mimeType := getTypeForFilename(fileName)
+	mimeType := http.DetectContentType(data)
 	putInput := &s3.PutObjectInput{
 		Bucket:      aws.String(bucket),
 		Key:         aws.String(fileName),
@@ -168,7 +168,7 @@ func (s ClientWithHelpers) UploadWithSettings(data []byte, bucket, fileName stri
 	}
 
 	if settings.MimeType == "" {
-		settings.MimeType = getTypeForFilename(fileName)
+		settings.MimeType = MIMEType(http.DetectContentType(data))
 	}
 
 	putInput := &s3.PutObjectInput{
@@ -242,7 +242,7 @@ func (s ClientWithHelpers) UploadWithSettingsRevised(data []byte, bucket string,
 	}
 
 	if settings.MimeType == "" {
-		settings.MimeType = getTypeForFilename(fullFileName)
+		settings.MimeType = MIMEType(http.DetectContentType(data))
 	}
 
 	putInput := &s3.PutObjectInput{
@@ -302,7 +302,7 @@ func (s ClientWithHelpers) UploadWith1DayExpiry(data []byte, bucket, fileName st
 	}
 
 	if mimeType == "" {
-		mimeType = getTypeForFilename(fileName)
+		mimeType = MIMEType(http.DetectContentType(data))
 	}
 
 	expiry := 24 * time.Hour
@@ -427,23 +427,6 @@ func (s ClientWithHelpers) UploadWithFileExtension(data []byte, bucket, filePref
 	return response, nil
 }
 
-func getTypeForFilename(f string) MIMEType {
-	ext := strings.ToLower(path.Ext(f))
-
-	switch ext {
-	case "pdf":
-		return MIMETypePDF
-	case "csv":
-		return MIMETypeCSV
-	case "zip":
-		return MIMETypeZIP
-	case "txt":
-		return MIMETypeText
-	}
-
-	return MIMETypeDefault
-}
-
 func (s ClientWithHelpers) GetObject(bucket string, fileName string, isDebug bool) (*s3.GetObjectOutput, error) {
 	if s.S3Client == nil {
 		return nil, ErrorS3ClientNotEstablished