feat(pkg/boards): add IsUserPartitionPreservationSupported function

pkg/board/os_image.go

@@ -0,0 +1,83 @@
+// This file is part of arduino-app-cli.
+//
+// Copyright 2025 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-app-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to license@arduino.cc.
+
+package board
+
+import (
+	"bufio"
+	"io"
+	"log/slog"
+	"strings"
+
+	"github.com/arduino/arduino-app-cli/pkg/board/remote"
+)
+
+const R0_IMAGE_VERSION_ID = "20250807-136"
+
+// GetOSImageVersion returns the version of the OS image used in the board.
+// It is used by the AppLab to enforce image version compatibility.
+func GetOSImageVersion(conn remote.RemoteConn) string {
+	f, err := conn.ReadFile("/etc/buildinfo")
+	if err != nil {
+		slog.Warn("Unable to read buildinfo file", "err", err, "using_default", R0_IMAGE_VERSION_ID)
+		return R0_IMAGE_VERSION_ID
+	}
+	defer f.Close()
+
+	if version, ok := parseOSImageVersion(f); ok {
+		slog.Info("found OS Image version", "version", version)
+		return version
+	}
+	slog.Warn("Unable to find OS Image version", "using_default", R0_IMAGE_VERSION_ID)
+	return R0_IMAGE_VERSION_ID
+}
+
+func parseOSImageVersion(r io.Reader) (string, bool) {
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+
+		key, value, ok := strings.Cut(line, "=")
+		if !ok || key != "BUILD_ID" {
+			continue
+		}
+
+		version := strings.Trim(value, `"' `)
+		if version != "" {
+			return version, true
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		return "", false
+	}
+
+	return "", false
+}
+
+type OSImageRelease struct {
+	VersionLabel string
+	ID           string
+	Latest       bool
+}
+
+// Calculates whether user partition preservation is supported,
+// according to the current and target OS image versions.
+//
+// Preservation is supported if both versions are not the R0 image.
+func IsUserPartitionPreservationSupported(conn remote.RemoteConn, targetImageVersion OSImageRelease) bool {
+	currentImageVersion := GetOSImageVersion(conn)
+	return targetImageVersion.ID != R0_IMAGE_VERSION_ID && currentImageVersion != R0_IMAGE_VERSION_ID
+}

pkg/board/os_image_test.go

@@ -0,0 +1,157 @@
+// This file is part of arduino-app-cli.
+//
+// Copyright 2025 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-app-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to license@arduino.cc.
+package board
+
+import (
+	"context"
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/arduino/arduino-app-cli/pkg/board/remote"
+)
+
+// implements remote.RemoteConn
+type MockRemoteConn struct {
+	ReadFileFunc func(path string) (io.ReadCloser, error)
+}
+
+func (m *MockRemoteConn) ReadFile(path string) (io.ReadCloser, error) {
+	return m.ReadFileFunc(path)
+}
+
+// Empty definitions
+func (m *MockRemoteConn) List(path string) ([]remote.FileInfo, error) {
+	return nil, nil
+}
+func (m *MockRemoteConn) MkDirAll(path string) error {
+	return nil
+}
+func (m *MockRemoteConn) Remove(path string) error {
+	return nil
+}
+func (m *MockRemoteConn) Stats(path string) (remote.FileInfo, error) {
+	return remote.FileInfo{}, nil
+}
+func (m *MockRemoteConn) WriteFile(data io.Reader, path string) error {
+	return nil
+}
+func (m *MockRemoteConn) GetCmd(cmd string, args ...string) remote.Cmder {
+	return nil
+}
+func (m *MockRemoteConn) Forward(ctx context.Context, localPort int, remotePort int) error {
+	return nil
+}
+func (m *MockRemoteConn) ForwardKillAll(ctx context.Context) error {
+	return nil
+}
+func createBuildInfoConnection(imageVersion string) remote.RemoteConn {
+	mockConn := MockRemoteConn{
+		ReadFileFunc: func(path string) (io.ReadCloser, error) {
+			return io.NopCloser(strings.NewReader(imageVersion)), nil
+		},
+	}
+	return &mockConn
+}
+
+func TestParseOSImageVersion(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+		found    bool
+	}{
+		{
+			name:     "valid build id",
+			input:    "BUILD_ID=\"20251006-395\"\nVARIANT_ID=xfce",
+			expected: "20251006-395",
+			found:    true,
+		},
+		{
+			name:  "missing build id",
+			input: "VARIANT_ID=xfce\n",
+			found: false,
+		},
+		{
+			name:  "empty build id",
+			input: "BUILD_ID=\n",
+			found: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, ok := parseOSImageVersion(strings.NewReader(tt.input))
+			if ok != tt.found || got != tt.expected {
+				t.Fatalf("got (%q, %v), expected (%q, %v)", got, ok, tt.expected, tt.found)
+			}
+		})
+	}
+}
+
+func TestGetOSImageVersion(t *testing.T) {
+	const R0_IMAGE_VERSION_ID = "20250807-136"
+	R0Version := createBuildInfoConnection(R0_IMAGE_VERSION_ID)
+	AnotherVersion := createBuildInfoConnection("BUILD_ID=20250101-001")
+	require.Equal(t, GetOSImageVersion(R0Version), R0_IMAGE_VERSION_ID)
+	require.Equal(t, GetOSImageVersion(AnotherVersion), "20250101-001")
+}
+
+func TestIsUserPartitionPreservationSupported(t *testing.T) {
+	const R0_IMAGE_VERSION_ID = "20250807-136"
+
+	R0Version := createBuildInfoConnection(R0_IMAGE_VERSION_ID)
+	AnotherVersion := createBuildInfoConnection("BUILD_ID=20250101-001")
+
+	tests := []struct {
+		name                    string
+		currentVersion          remote.RemoteConn
+		targetVersion           string
+		isPreservationSupported bool
+	}{
+		{
+			name:                    "both versions are *not* R0",
+			currentVersion:          AnotherVersion,
+			targetVersion:           "20250101-001",
+			isPreservationSupported: true,
+		},
+		{
+			name:                    "current version is R0",
+			currentVersion:          R0Version,
+			targetVersion:           "20250101-001",
+			isPreservationSupported: false,
+		},
+		{
+			name:                    "target version is R0",
+			currentVersion:          AnotherVersion,
+			targetVersion:           R0_IMAGE_VERSION_ID,
+			isPreservationSupported: false,
+		},
+		{
+			name:                    "both versions are R0",
+			currentVersion:          R0Version,
+			targetVersion:           R0_IMAGE_VERSION_ID,
+			isPreservationSupported: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			isPreservationSupported := IsUserPartitionPreservationSupported(tt.currentVersion, OSImageRelease{ID: tt.targetVersion})
+			require.Equal(t, isPreservationSupported, tt.isPreservationSupported)
+		})
+	}
+}