feat: use fileutil.SaveFile() to save file via tempfile

server/src/application/saveGameState.go

@@ -2,8 +2,8 @@ package application
 
 import (
 	"encoding/json"
-	"os"
 	"path"
+	"sirlab.de/go/knowyt/fileutil"
 	"sirlab.de/go/knowyt/game"
 )
 
@@ -14,22 +14,8 @@ func (app *Application) saveGameState(gm *game.Game) error {
 		return errMarshal
 	}
 
-	dirName := path.Join(app.config.DataDir, "games", gm.GetId())
+	filename := path.Join(app.config.DataDir, "games", gm.GetId(), "state.json")
-	f, err := os.CreateTemp(dirName, "state.tmp-*.json")
+	if err := fileutil.SaveFile(filename, jsonString); err != nil {
-	if err != nil {
-		return err
-	}
-	defer os.Remove(f.Name())
-
-	if _, err := f.Write(jsonString); err != nil {
-		return err
-	}
-	if err := f.Close(); err != nil {
-		return err
-	}
-
-	fileName := path.Join(dirName, "state.json")
-	if err := os.Rename(f.Name(), fileName); err != nil {
 		return err
 	}
 

server/src/fileutil/SaveFile.go

@@ -0,0 +1,29 @@
+package fileutil
+
+import (
+	"os"
+	"path"
+)
+
+func SaveFile(filename string, data []byte) error {
+	dirname := path.Dir(filename)
+	tmpFile, err := os.CreateTemp(dirname, "save-*.tmp")
+	if err != nil {
+		return err
+	}
+	defer os.Remove(tmpFile.Name())
+
+	if _, err := tmpFile.Write(data); err != nil {
+		return err
+	}
+	if err := tmpFile.Close(); err != nil {
+		return err
+	}
+
+	if err := os.Rename(tmpFile.Name(), filename); err != nil {
+		return err
+	}
+
+	return nil
+
+}

server/src/game/game.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"sirlab.de/go/knowyt/engine"
+	"sirlab.de/go/knowyt/fileutil"
 	"sirlab.de/go/knowyt/quote"
 	"time"
 )
@@ -60,7 +61,7 @@ func (gm *Game) SaveGame() error {
 	if jsonBytes, err := json.Marshal(gmJson); err != nil {
 		return err
 	} else {
-		if err := os.WriteFile(gm.filename, jsonBytes, 0666); err != nil {
+		if err := fileutil.SaveFile(gm.filename, jsonBytes); err != nil {
 			return err
 		}
 	}

server/src/user/user.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"path"
+	"sirlab.de/go/knowyt/fileutil"
 	"strings"
 	"time"
 )
@@ -62,7 +63,7 @@ func (usr *User) SaveUser() error {
 	if jsonBytes, err := json.Marshal(userJson); err != nil {
 		return err
 	} else {
-		if err := os.WriteFile(usr.filename, jsonBytes, 0666); err != nil {
+		if err := fileutil.SaveFile(usr.filename, jsonBytes); err != nil {
 			return err
 		}
 	}