fix: preserve files untracked by Git on plugin update (#1995)

Co-authored-by: Trevor Brown <[email protected]>

Author: andrecloutier

internal/git/git.go

@@ -115,10 +115,10 @@ func (r Repo) Update(ref string) (string, string, string, error) {
 		// If on a branch checkout the latest version of it from the remote
 		branch := head.Name()
 		ref = branch.String()
-		checkoutOptions = git.CheckoutOptions{Branch: branch, Force: true}
+		checkoutOptions = git.CheckoutOptions{Branch: branch, Keep: true}
 	} else {
 		// Checkout ref if provided
-		checkoutOptions = git.CheckoutOptions{Hash: plumbing.NewHash(ref), Force: true}
+		checkoutOptions = git.CheckoutOptions{Hash: plumbing.NewHash(ref), Keep: true}
 	}
 
 	fetchOptions := git.FetchOptions{RemoteName: DefaultRemoteName, Force: true, RefSpecs: []config.RefSpec{

internal/git/git_test.go

@@ -153,6 +153,40 @@ func TestRepoUpdate(t *testing.T) {
 		assert.Equal(t, latestHash, currentHash)
 	})
 
+	t.Run("updates repo while leaving untracked files in place", func(t *testing.T) {
+		latestHash, err := getCurrentCommit(directory)
+		assert.Nil(t, err)
+
+		_, err = checkoutPreviousCommit(directory)
+		assert.Nil(t, err)
+
+		untrackedDir := filepath.Join(directory, "untracked")
+		err = os.Mkdir(untrackedDir, 0o777)
+		assert.Nil(t, err)
+
+		expectedContent := []byte("dummy_content")
+		err = os.WriteFile(filepath.Join(untrackedDir, "file_one"), expectedContent, 0o777)
+		assert.Nil(t, err)
+		err = os.WriteFile(filepath.Join(untrackedDir, "file_two"), expectedContent, 0o777)
+		assert.Nil(t, err)
+
+		updatedToRef, _, _, err := repo.Update("")
+		assert.Nil(t, err)
+		assert.Equal(t, "refs/heads/master", updatedToRef)
+
+		currentHash, err := getCurrentCommit(directory)
+		assert.Nil(t, err)
+		assert.Equal(t, latestHash, currentHash)
+
+		content, err := os.ReadFile(filepath.Join(untrackedDir, "file_one"))
+		assert.Nil(t, err)
+		assert.Equal(t, expectedContent, content)
+
+		content, err = os.ReadFile(filepath.Join(untrackedDir, "file_two"))
+		assert.Nil(t, err)
+		assert.Equal(t, expectedContent, content)
+	})
+
 	t.Run("Returns error when specified ref does not exist", func(t *testing.T) {
 		ref := "non-existent"
 		updatedToRef, _, _, err := repo.Update(ref)