extract and test makeBackup

app/migrator/migrator.go

@@ -61,29 +61,42 @@ func ImportComments(p ImportParams) error {
 	return importer.Import(fh, p.SiteID)
 }
 
-// AutoBackup runs daily export to local files
+// AutoBackup runs daily export to local files, keeps up to keepMax backups for given siteID
 func AutoBackup(exporter Exporter, backupLocation string, siteID string, keepMax int) {
 	log.Print("[INFO] activate auto-backup")
 	tick := time.NewTicker(24 * time.Hour)
 	for range tick.C {
-		log.Print("[DEBUG] make backup")
-		fh, err := os.Create(fmt.Sprintf("%s/backup-%s-%s.gz", backupLocation, siteID, time.Now().Format("20060102")))
+		_, err := makeBackup(exporter, backupLocation, siteID)
 		if err != nil {
-			log.Printf("[WARN] can't create backup file, %s", err)
+			log.Printf("[WARN] auto-backup for %s failed, %s", siteID, err)
 			continue
 		}
-		gz := gzip.NewWriter(fh)
-
-		if err = exporter.Export(gz, siteID); err != nil {
-			log.Printf("[WARN] export failed, %+v", err)
-		}
-		_ = gz.Close()
-		_ = fh.Close()
-
 		removeOldBackupFiles(backupLocation, siteID, keepMax)
 	}
 }
 
+func makeBackup(exporter Exporter, backupLocation string, siteID string) (string, error) {
+	log.Printf("[DEBUG] make backup for %s", siteID)
+	backupFile := fmt.Sprintf("%s/backup-%s-%s.gz", backupLocation, siteID, time.Now().Format("20060102"))
+	fh, err := os.Create(backupFile)
+	if err != nil {
+		return "", errors.Wrapf(err, "can't create backup file %s", backupFile)
+	}
+	gz := gzip.NewWriter(fh)
+
+	if err = exporter.Export(gz, siteID); err != nil {
+		return "", errors.Wrapf(err, "export failed for %s", siteID)
+	}
+	if err = gz.Close(); err != nil {
+		return "", errors.Wrapf(err, "can't close gz for %s", backupFile)
+	}
+	if err = fh.Close(); err != nil {
+		return "", errors.Wrapf(err, "can't close file handler for %s", backupFile)
+	}
+	log.Printf("[DEBUG] created backup file %s", backupFile)
+	return backupFile, nil
+}
+
 func removeOldBackupFiles(backupLocation string, siteID string, keepMax int) {
 	files, err := ioutil.ReadDir(backupLocation)
 	if err != nil {

app/migrator/migrator_test.go

@@ -2,19 +2,21 @@ package migrator
 
 import (
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 )
 
 func TestMigrator_RemoveOldBackupFiles(t *testing.T) {
-	loc := "tmp/remark-backups.test"
+	loc := "/tmp/remark-backups.test"
 	defer os.RemoveAll(loc)
 
 	os.MkdirAll(loc, 0700)
-	for i := 0; i < 10; i++ {
+	for i := 1; i <= 10; i++ {
 		fname := fmt.Sprintf("%s/backup-site1-201712%02d.gz", loc, i)
 		err := ioutil.WriteFile(fname, []byte("blah"), 0600)
 		assert.Nil(t, err)
@@ -24,7 +26,29 @@ func TestMigrator_RemoveOldBackupFiles(t *testing.T) {
 	ff, err := ioutil.ReadDir(loc)
 	assert.Nil(t, err)
 	assert.Equal(t, 3, len(ff), "should keep 3 files only")
-	assert.Equal(t, "backup-site1-20171207.gz", ff[0].Name())
-	assert.Equal(t, "backup-site1-20171208.gz", ff[1].Name())
-	assert.Equal(t, "backup-site1-20171209.gz", ff[2].Name())
+	assert.Equal(t, "backup-site1-20171208.gz", ff[0].Name())
+	assert.Equal(t, "backup-site1-20171209.gz", ff[1].Name())
+	assert.Equal(t, "backup-site1-20171210.gz", ff[2].Name())
+}
+
+func TestMigrator_MakeBackup(t *testing.T) {
+	loc := "/tmp/remark-backups.test"
+	defer os.RemoveAll(loc)
+	os.MkdirAll(loc, 0700)
+
+	fname, err := makeBackup(&mockExporter{}, loc, "site1")
+	assert.NoError(t, err)
+	expFile := fmt.Sprintf("/tmp/remark-backups.test/backup-site1-%s.gz", time.Now().Format("20060102"))
+	assert.Equal(t, expFile, fname)
+
+	fi, err := os.Lstat(expFile)
+	assert.NoError(t, err)
+	assert.Equal(t, int64(52), fi.Size())
+}
+
+type mockExporter struct{}
+
+func (mock *mockExporter) Export(w io.Writer, siteID string) error {
+	w.Write([]byte("some export blah blah 1234567890"))
+	return nil
 }