light refactoring

internal/protocol/upload/http_client.go

@@ -1,18 +1,15 @@
 package upload
 
 import (
-	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io"
-	"mime/multipart"
 	"net/http"
 	"os"
-	"path/filepath"
 
 	"merkle-file-uploader/internal/merkle"
 	"merkle-file-uploader/internal/protocol"
+	"merkle-file-uploader/internal/utils"
 )
 
 var (
@@ -38,7 +35,7 @@ func (h *HttpUploader) UploadFilesFrom(filePaths []string) (
 	merkleRoot string,
 	err error,
 ) {
-	requestBody, formDataContentType, err := prepareRequestBody(filePaths)
+	requestBody, formDataContentType, err := utils.MultipartFormFromFiles(filePaths)
 	if err != nil {
 		err = fmt.Errorf("%w: error preparing POST request body: %s", ErrFailedUpload, err)
 
@@ -98,39 +95,3 @@ func (h *HttpUploader) computeMerkleRoot(filePaths []string) (merkleRoot string,
 
 	return tree.Root.Data, nil
 }
-
-func prepareRequestBody(filePaths []string) (requestBody bytes.Buffer, formDataContentType string, err error) {
-	multipartWriter := multipart.NewWriter(&requestBody)
-
-	for _, fp := range filePaths {
-		var file *os.File
-		file, err = os.Open(fp)
-		if err != nil {
-			return
-		}
-
-		var filePart io.Writer
-		filePart, err = multipartWriter.CreateFormFile("files", filepath.Base(fp))
-		if err != nil {
-			return
-		}
-
-		// copy the file content to the form file part
-		if _, err = io.Copy(filePart, file); err != nil {
-			return
-		}
-
-		if err = file.Close(); err != nil {
-			return
-		}
-	}
-
-	// Close the multipart writer to finish building the request body
-	if err = multipartWriter.Close(); err != nil {
-		return
-	}
-
-	formDataContentType = multipartWriter.FormDataContentType()
-
-	return
-}

internal/utils/http.go

@@ -1,9 +1,14 @@
 package utils
 
 import (
+	"bytes"
 	"encoding/json"
+	"io"
 	"log"
+	"mime/multipart"
 	"net/http"
+	"os"
+	"path/filepath"
 )
 
 func HttpOkJson(w http.ResponseWriter, payload any) (err error) {
@@ -16,3 +21,39 @@ func HttpError(w http.ResponseWriter, statusCode int, err error) {
 	log.Printf("%s: %s\n", http.StatusText(statusCode), err)
 	http.Error(w, http.StatusText(statusCode), statusCode)
 }
+
+func MultipartFormFromFiles(filePaths []string) (multipartForm bytes.Buffer, formDataContentType string, err error) {
+	multipartWriter := multipart.NewWriter(&multipartForm)
+
+	for _, fp := range filePaths {
+		var file *os.File
+		file, err = os.Open(fp)
+		if err != nil {
+			return
+		}
+
+		var filePart io.Writer
+		filePart, err = multipartWriter.CreateFormFile("files", filepath.Base(fp))
+		if err != nil {
+			return
+		}
+
+		// copy the file content to the form file part
+		if _, err = io.Copy(filePart, file); err != nil {
+			return
+		}
+
+		if err = file.Close(); err != nil {
+			return
+		}
+	}
+
+	// Close the multipart writer to finish building the request body
+	if err = multipartWriter.Close(); err != nil {
+		return
+	}
+
+	formDataContentType = multipartWriter.FormDataContentType()
+
+	return
+}