Launcher, app/base, sentry, update service

internal/versioner/versioner.go

@@ -0,0 +1,81 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package versioner
+
+import (
+	"errors"
+	"io/ioutil"
+	"path/filepath"
+	"sort"
+
+	"github.com/Masterminds/semver/v3"
+)
+
+var (
+	ErrNoVersions   = errors.New("no available versions")
+	ErrNoExecutable = errors.New("no executable found")
+)
+
+// Versioner manages a directory of versioned app directories.
+type Versioner struct {
+	root string
+}
+
+func New(root string) *Versioner {
+	return &Versioner{root: root}
+}
+
+// ListVersions returns a collection of all available version numbers, sorted from newest to oldest.
+func (v *Versioner) ListVersions() (Versions, error) {
+	dirs, err := ioutil.ReadDir(v.root)
+	if err != nil {
+		return nil, err
+	}
+
+	var versions Versions
+
+	for _, dir := range dirs {
+		version, err := semver.StrictNewVersion(dir.Name())
+		if err != nil {
+			continue
+		}
+
+		// NOTE: If it's a bad directory, maybe delete it?
+
+		versions = append(versions, &Version{
+			version: version,
+			path:    filepath.Join(v.root, dir.Name()),
+		})
+	}
+
+	sort.Sort(sort.Reverse(versions))
+
+	return versions, nil
+}
+
+// GetExecutableInDirectory returns the full path to the executable in the given directory, if present.
+// It returns an error if the executable is missing or does not have executable permissions set.
+func (v *Versioner) GetExecutableInDirectory(name, directory string) (string, error) {
+	exe := filepath.Join(directory, getExeName(name))
+
+	if !fileExists(exe) || !fileIsExecutable(exe) {
+		return "", ErrNoExecutable
+	}
+
+	return exe, nil
+}