fix(plugins): reset cache repo modifications before update

Signed-off-by: OlTrenin <rucapashna@gmail.com>

internal/plugin/installer/vcs_installer.go

@@ -21,6 +21,7 @@ import (
 	stdfs "io/fs"
 	"log/slog"
 	"os"
+	"os/exec"
 	"sort"
 
 	"github.com/Masterminds/semver/v3"
@@ -95,12 +96,63 @@ func (i *VCSInstaller) Install() error {
 	return fs.CopyDir(i.Repo.LocalPath(), i.Path())
 }
 
+// resetRepo discards all local modifications in the repository.
+// This is used to clean the cached repository before updating.
+func resetRepo(repo vcs.Repo) error {
+	// Check the VCS type to determine the appropriate reset command
+	switch repo.Vcs() {
+	case vcs.Git:
+		// For Git, use 'git reset --hard' to discard all local changes
+		cmd := exec.Command("git", "reset", "--hard")
+		cmd.Dir = repo.LocalPath()
+		if output, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("git reset failed: %w, output: %s", err, output)
+		}
+		return nil
+	case vcs.Hg:
+		// For Mercurial, use 'hg revert --all --no-backup'
+		cmd := exec.Command("hg", "revert", "--all", "--no-backup")
+		cmd.Dir = repo.LocalPath()
+		if output, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("hg revert failed: %w, output: %s", err, output)
+		}
+		return nil
+	case vcs.Bzr:
+		// For Bazaar, use 'bzr revert'
+		cmd := exec.Command("bzr", "revert")
+		cmd.Dir = repo.LocalPath()
+		if output, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("bzr revert failed: %w, output: %s", err, output)
+		}
+		return nil
+	case vcs.Svn:
+		// For SVN, use 'svn revert -R .'
+		cmd := exec.Command("svn", "revert", "-R", ".")
+		cmd.Dir = repo.LocalPath()
+		if output, err := cmd.CombinedOutput(); err != nil {
+			return fmt.Errorf("svn revert failed: %w, output: %s", err, output)
+		}
+		return nil
+	default:
+		return fmt.Errorf("unsupported VCS type: %v", repo.Vcs())
+	}
+}
+
 // Update updates a remote repository
 func (i *VCSInstaller) Update() error {
 	slog.Debug("updating", "source", i.Repo.Remote())
+
+	// Reset any local modifications in the cache directory before updating.
+	// The cached repository is managed by Helm and should not contain user modifications.
+	// Any modifications made by Helm itself (e.g., to plugin.yaml during installation)
+	// should be discarded before attempting to update.
 	if i.Repo.IsDirty() {
-		return errors.New("plugin repo was modified")
+		slog.Debug("resetting local modifications in cache", "path", i.Repo.LocalPath())
+		if err := resetRepo(i.Repo); err != nil {
+			return fmt.Errorf("failed to reset local modifications: %w", err)
+		}
 	}
+
 	if err := i.Repo.Update(); err != nil {
 		return err
 	}

internal/plugin/installer/vcs_installer_test.go

@@ -175,15 +175,88 @@ func TestVCSInstallerUpdate(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// Test update failure
-	if err := os.Remove(filepath.Join(vcsInstaller.Repo.LocalPath(), "plugin.yaml")); err != nil {
+	// Test that local modifications are automatically reset during update
+	// Remove plugin.yaml to simulate modifications
+	pluginYamlPath := filepath.Join(vcsInstaller.Repo.LocalPath(), "plugin.yaml")
+	if err := os.Remove(pluginYamlPath); err != nil {
 		t.Fatal(err)
 	}
-	// Testing update for error
-	if err := Update(vcsInstaller); err == nil {
-		t.Fatalf("expected error for plugin modified, got none")
-	} else if err.Error() != "plugin repo was modified" {
-		t.Fatalf("expected error for plugin modified, got (%v)", err)
+
+	// Verify the repo is dirty
+	if !vcsInstaller.Repo.IsDirty() {
+		t.Fatal("expected repo to be dirty after removing plugin.yaml")
+	}
+
+	// Update should succeed because local modifications are automatically reset
+	if err := Update(vcsInstaller); err != nil {
+		t.Fatalf("update should succeed after automatic reset, got error: %v", err)
+	}
+
+	// Verify plugin.yaml was restored after reset
+	if _, err := os.Stat(pluginYamlPath); err != nil {
+		t.Fatalf("plugin.yaml should be restored after update, got error: %v", err)
+	}
+
+}
+
+func TestResetRepo(t *testing.T) {
+	// Use a real git repository by cloning a test repo
+	ensure.HelmHome(t)
+
+	source := "https://github.com/adamreese/helm-env"
+
+	i, err := NewForSource(source, "")
+	if err != nil {
+		t.Fatalf("unexpected error: %s", err)
+	}
+
+	vcsInstaller, ok := i.(*VCSInstaller)
+	if !ok {
+		t.Fatal("expected a VCSInstaller")
 	}
 
+	// Clone the repository
+	if err := vcsInstaller.sync(vcsInstaller.Repo); err != nil {
+		if strings.Contains(err.Error(), "Could not resolve host: github.com") {
+			t.Skip("Unable to run test without Internet access")
+		}
+		t.Fatalf("Failed to sync repo: %v", err)
+	}
+
+	// Modify an existing file to make the repo dirty
+	pluginYaml := filepath.Join(vcsInstaller.Repo.LocalPath(), "plugin.yaml")
+	originalContent, err := os.ReadFile(pluginYaml)
+	if err != nil {
+		t.Fatalf("Failed to read plugin.yaml: %v", err)
+	}
+
+	modifiedContent := append(originalContent, []byte("\n# Test modification\n")...)
+	if err := os.WriteFile(pluginYaml, modifiedContent, 0644); err != nil {
+		t.Fatalf("Failed to modify plugin.yaml: %v", err)
+	}
+
+	// Verify the repo is dirty
+	if !vcsInstaller.Repo.IsDirty() {
+		t.Fatal("Expected repo to be dirty after modifying plugin.yaml")
+	}
+
+	// Reset the repo
+	if err := resetRepo(vcsInstaller.Repo); err != nil {
+		t.Fatalf("resetRepo failed: %v", err)
+	}
+
+	// Verify the repo is clean
+	if vcsInstaller.Repo.IsDirty() {
+		t.Fatal("Expected repo to be clean after reset")
+	}
+
+	// Verify the plugin.yaml was restored to original content
+	restoredContent, err := os.ReadFile(pluginYaml)
+	if err != nil {
+		t.Fatalf("Failed to read plugin.yaml after reset: %v", err)
+	}
+
+	if string(restoredContent) != string(originalContent) {
+		t.Fatal("Expected plugin.yaml to be restored to original content after reset")
+	}
 }