[Go] echo의 파일 업로드 처리(서버 측)

개시하다

이루어지다

package main

import (
	"fmt"
	"github.com/labstack/echo/v4"
	"io"
	"os"
	"strings"
)

func upload(c echo.Context) error {
	file, err := c.FormFile("file")
	if err != nil {
		return err
	}
	src, err := file.Open()
	if err != nil {
		return err
	}
	defer src.Close()

	fileModel := strings.Split(file.Filename, ".")
	fileName := fileModel[0]
	extension := fileModel[1]
	dst, err := os.Create(fmt.Sprintf("%s_out.%s", fileName, extension))
	if err != nil {
		return err
	}
	defer dst.Close()

	if _, err = io.Copy(dst, src); err != nil {
		return err
	}

	return c.HTML(200, "Image has been saved.")
}

func main() {
	e := echo.New()
	e.POST("/upload", upload)
	e.Start(":8080")
}

테스트

package main

import (
	"bytes"
	"github.com/labstack/echo/v4"
	"github.com/stretchr/testify/assert"
	"io"
	"io/ioutil"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"os"
	"testing"
)

func TestUpload(t *testing.T) {

	// テストサーバ起動
	e := echo.New()
	e.POST("/upload", upload)
	testServer := httptest.NewServer(e)
	defer testServer.Close()

	// クライアントの画像ファイルアップロード処理
	var buffer bytes.Buffer
	writer := multipart.NewWriter(&buffer)
	fileWriter, err := writer.CreateFormFile("file", "test.png")
	if err != nil{
		t.Fatalf("Failed to create file writer. %s", err)
	}

	readFile, err := os.Open("test.png")
	if err != nil {
		t.Fatalf("Failed to open file. %s", err)
	}
	defer readFile.Close()
	io.Copy(fileWriter, readFile)
	writer.Close()

	res, err := http.Post(testServer.URL + "/upload", writer.FormDataContentType(), &buffer)
	if err != nil{
		t.Fatalf("Failed to POST request. %s", err)
	}

	// API レスポンス検証
	message, err := ioutil.ReadAll(res.Body)
	res.Body.Close()
	if err != nil {
		t.Fatalf("Failed to read HTTP response body. %s", err)
	}
	assert.Equal(t, "Image has been saved.", string(message))

	// アップロードを行った画像ファイルとサーバ側が保存した画像の内容が一致しているかどうか検証
	outFile, err := os.Open("test_out.png")
	if err != nil {
		t.Fatalf("Failed to open file. %s", err)
	}
	defer outFile.Close()
	var expectedBytes []byte
	readFile.Write(expectedBytes)
	var actualBytes []byte
	outFile.Write(actualBytes)
	assert.Equal(t, expectedBytes, actualBytes)
}

$ go test -run TestUpload
PASS
ok      go-sample       0.116s