Refactor legacy code (#35708)

And by the way, remove the legacy TODO, split large functions into small
ones, and add more tests

modules/git/hook.go

@@ -47,30 +47,16 @@ func GetHook(repoPath, name string) (*Hook, error) {
 		name: name,
 		path: filepath.Join(repoPath, filepath.Join("hooks", name+".d", name)),
 	}
-	isFile, err := util.IsFile(h.path)
-	if err != nil {
-		return nil, err
-	}
-	if isFile {
-		data, err := os.ReadFile(h.path)
-		if err != nil {
-			return nil, err
-		}
+	if data, err := os.ReadFile(h.path); err == nil {
 		h.IsActive = true
 		h.Content = string(data)
 		return h, nil
+	} else if !os.IsNotExist(err) {
+		return nil, err
 	}
 
 	samplePath := filepath.Join(repoPath, "hooks", name+".sample")
-	isFile, err = util.IsFile(samplePath)
-	if err != nil {
-		return nil, err
-	}
-	if isFile {
-		data, err := os.ReadFile(samplePath)
-		if err != nil {
-			return nil, err
-		}
+	if data, err := os.ReadFile(samplePath); err == nil {
 		h.Sample = string(data)
 	}
 	return h, nil

modules/setting/config_provider.go

@@ -202,11 +202,11 @@ func NewConfigProviderFromFile(file string) (ConfigProvider, error) {
 	loadedFromEmpty := true
 
 	if file != "" {
-		isFile, err := util.IsFile(file)
+		isExist, err := util.IsExist(file)
 		if err != nil {
-			return nil, fmt.Errorf("unable to check if %q is a file. Error: %v", file, err)
+			return nil, fmt.Errorf("unable to check if %q exists: %v", file, err)
 		}
-		if isFile {
+		if isExist {
 			if err = cfg.Append(file); err != nil {
 				return nil, fmt.Errorf("failed to load config file %q: %v", file, err)
 			}

modules/util/path.go

@@ -115,15 +115,10 @@ func IsDir(dir string) (bool, error) {
 	return false, err
 }
 
-// IsFile returns true if given path is a file,
-// or returns false when it's a directory or does not exist.
-func IsFile(filePath string) (bool, error) {
-	f, err := os.Stat(filePath)
+func IsRegularFile(filePath string) (bool, error) {
+	f, err := os.Lstat(filePath)
 	if err == nil {
-		return !f.IsDir(), nil
-	}
-	if os.IsNotExist(err) {
-		return false, nil
+		return f.Mode().IsRegular(), nil
 	}
 	return false, err
 }