fix(generate-entry): refuse a container that does not exist

Signed-off-by: Luca Di Maio <luca.dimaio1@gmail.com>

pkg/commands/generate_entry.go

@@ -146,12 +146,17 @@ func (c *GenerateEntryCommand) resolveTargets(
 		// can't be reached — we fall back to the name in Execute.
 		images := map[string]string{}
 		if listResult, err := c.listCommand.Execute(ctx); err == nil {
+			found := false
 			for _, container := range listResult.Containers {
 				if container.Name == opts.ContainerName {
 					images[opts.ContainerName] = container.Image
+					found = true
 					break
 				}
 			}
+			if !found && !opts.Delete {
+				return nil, nil, "", fmt.Errorf("cannot find container %s, please create it first", opts.ContainerName)
+			}
 		}
 		return []string{opts.ContainerName}, images, opts.Icon, nil
 	default:

pkg/commands/generate_entry_test.go

@@ -225,3 +225,44 @@ func TestGenerateEntryCommand_SingleModeUsesImageHint(t *testing.T) {
 	assert.Contains(t, string(content), "ubuntu-distrobox.png",
 		"single-mode must key auto-detection off the image (cached icon path), not the box name 'dev'")
 }
+
+// generate-entry refuses to write an entry for a container that does not
+// exist (matches the shell, distrobox-generate-entry:285-288).
+func TestGenerateEntryCommand_RefusesNonExistentContainer(t *testing.T) {
+	tempDir := t.TempDir()
+	mock := &testutil.MockContainerManager{
+		ListContainersResult: []containermanager.Container{
+			{Name: "other", Image: "alpine", Status: "Exited", Labels: map[string]string{"manager": "distrobox"}},
+		},
+	}
+	listCmd := commands.NewListCommand(&config.Values{}, mock)
+	cmd := commands.NewGenerateEntryCommand(&config.Values{}, listCmd)
+
+	err := cmd.Execute(context.Background(), &commands.GenerateEntryOptions{
+		ContainerName:       "ghost",
+		DesktopEntryBaseDir: tempDir,
+		DistroboxPath:       "/usr/bin/distrobox",
+	})
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "cannot find container ghost")
+	assert.NoFileExists(t, filepath.Join(tempDir, "applications", "ghost.desktop"))
+}
+
+// --delete must NOT require the container to exist (its box may already
+// be gone when rm cleans up the entry).
+func TestGenerateEntryCommand_DeleteNonExistentNoError(t *testing.T) {
+	tempDir := t.TempDir()
+	mock := &testutil.MockContainerManager{
+		ListContainersResult: []containermanager.Container{},
+	}
+	listCmd := commands.NewListCommand(&config.Values{}, mock)
+	cmd := commands.NewGenerateEntryCommand(&config.Values{}, listCmd)
+
+	err := cmd.Execute(context.Background(), &commands.GenerateEntryOptions{
+		ContainerName:       "ghost",
+		Delete:              true,
+		DesktopEntryBaseDir: tempDir,
+		DistroboxPath:       "/usr/bin/distrobox",
+	})
+	require.NoError(t, err)
+}