addressing review comments

cmd/challenge/catalog.go

@@ -35,14 +35,14 @@ func newCatalogCommand(cli labcli.CLI) *cobra.Command {
 		&opts.category,
 		"category",
 		[]string{},
-		`Category to filter by - one or multiple categories like linux, containers, kubernetes, ... (an empty string means all)`,
+		`Category to filter by - one or multiple categories like linux, containers, kubernetes`,
 	)
 
 	flags.StringSliceVar(
 		&opts.status,
 		"status",
 		[]string{},
-		`status to filter by - one or multiple status like todo, attempted, solved ... (empty means all))`,
+		`status to filter by - one or multiple status like todo, attempted, solved)`,
 	)
 
 	return cmd

internal/api/challenges.go

@@ -116,15 +116,13 @@ type ListChallengesOptions struct {
 func (c *Client) ListChallenges(ctx context.Context, opts *ListChallengesOptions) ([]*Challenge, error) {
 	var challenges []*Challenge
 	query := url.Values{}
-	if opts.Category != nil {
-		for _, category := range opts.Category {
-			query.Add("category",category)
-		}
+
+	for _, category := range opts.Category {
+		query.Add("category", category)
 	}
-	if opts.Status != nil {
-		for _, status := range opts.Status {
-			query.Add("status",status)
-		}
+
+	for _, status := range opts.Status {
+		query.Add("status", status)
 	}
 
 	return challenges, c.GetInto(ctx, "/challenges", query, nil, &challenges)