fix(cli): harden legacy select helpers

Co-Authored-By: Virgil <virgil@lethean.io>

pkg/cli/prompt.go

@@ -55,6 +55,10 @@ func Prompt(label, defaultVal string) (string, error) {
 
 // Select presents numbered options and returns the selected value.
 func Select(label string, options []string) (string, error) {
+	if len(options) == 0 {
+		return "", nil
+	}
+
 	fmt.Println(compileGlyphs(label))
 	for i, opt := range options {
 		fmt.Printf("  %d. %s\n", i+1, compileGlyphs(opt))
@@ -76,6 +80,10 @@ func Select(label string, options []string) (string, error) {
 
 // MultiSelect presents checkboxes (space-separated numbers).
 func MultiSelect(label string, options []string) ([]string, error) {
+	if len(options) == 0 {
+		return []string{}, nil
+	}
+
 	fmt.Println(compileGlyphs(label))
 	for i, opt := range options {
 		fmt.Printf("  %d. %s\n", i+1, compileGlyphs(opt))
@@ -91,7 +99,10 @@ func MultiSelect(label string, options []string) ([]string, error) {
 		return nil, err
 	}
 
-	var selected []string
+	var (
+		selected []string
+		seen     = make(map[int]bool, len(options))
+	)
 	normalized := strings.NewReplacer(",", " ").Replace(input)
 	for _, s := range strings.Fields(normalized) {
 		if strings.Contains(s, "-") {
@@ -105,7 +116,10 @@ func MultiSelect(label string, options []string) ([]string, error) {
 				continue
 			}
 			for n := start; n <= end; n++ {
-				selected = append(selected, options[n-1])
+				if !seen[n-1] {
+					seen[n-1] = true
+					selected = append(selected, options[n-1])
+				}
 			}
 			continue
 		}
@@ -114,7 +128,10 @@ func MultiSelect(label string, options []string) ([]string, error) {
 		if convErr != nil || n < 1 || n > len(options) {
 			continue
 		}
-		selected = append(selected, options[n-1])
+		if !seen[n-1] {
+			seen[n-1] = true
+			selected = append(selected, options[n-1])
+		}
 	}
 	return selected, nil
 }

pkg/cli/prompt_test.go

@@ -61,6 +61,12 @@ func TestSelect_Bad_EOF(t *testing.T) {
 	assert.ErrorIs(t, err, io.EOF)
 }
 
+func TestSelect_Good_EmptyOptions(t *testing.T) {
+	val, err := Select("Pick", nil)
+	assert.NoError(t, err)
+	assert.Empty(t, val)
+}
+
 func TestMultiSelect_Good(t *testing.T) {
 	SetStdin(strings.NewReader("1 3\n"))
 	defer SetStdin(nil)
@@ -88,6 +94,21 @@ func TestMultiSelect_Bad_EOFReturnsEmptySelection(t *testing.T) {
 	assert.Empty(t, vals)
 }
 
+func TestMultiSelect_Good_DedupesSelections(t *testing.T) {
+	SetStdin(strings.NewReader("1 1 2-3 2\n"))
+	defer SetStdin(nil)
+
+	vals, err := MultiSelect("Pick", []string{"a", "b", "c"})
+	assert.NoError(t, err)
+	assert.Equal(t, []string{"a", "b", "c"}, vals)
+}
+
+func TestMultiSelect_Good_EmptyOptions(t *testing.T) {
+	vals, err := MultiSelect("Pick", nil)
+	assert.NoError(t, err)
+	assert.Empty(t, vals)
+}
+
 func TestConfirm_Good(t *testing.T) {
 	SetStdin(strings.NewReader("y\n"))
 	defer SetStdin(nil)