Add MultiSelect option to toggle option under cursor when submitting empty prompt

CHANGELOG.md

@@ -4,7 +4,9 @@
 
 ## [Unreleased] <!-- ReleaseDate -->
 
-- No changes since the latest release below.
+### Features
+
+- Added `select_on_empty_submit` to MultiSelect to toggle option under cursor when submitting an empty prompt.
 
 ## [0.9.3] - 2026-02-06
 

inquire/src/prompts/multiselect/mod.rs

@@ -122,6 +122,13 @@ pub struct MultiSelect<'a, T> {
     /// config is treated as the only source of truth. If you want to customize colors
     /// and still support NO_COLOR, you will have to do this on your end.
     pub render_config: RenderConfig<'a>,
+
+    /// If true, will select the option under the cursor if the prompt is submitted without any
+    /// selections.
+    ///
+    /// This allows the MultiSelect to operate like a [Select](crate::Select) if the normal toggle
+    /// selection key has not been pressed.
+    select_on_empty_submit: Option<bool>,
 }
 
 impl<'a, T> MultiSelect<'a, T>
@@ -236,6 +243,7 @@ where
             formatter: Self::DEFAULT_FORMATTER,
             validator: None,
             render_config: get_configuration(),
+            select_on_empty_submit: None,
         }
     }
 
@@ -257,6 +265,15 @@ where
         self
     }
 
+    /// Enables selecting the current option when submitting without any selected options.
+    ///
+    /// This allows the MultiSelect to operate like a [Select](crate::Select) if the normal toggle
+    /// selection key has not been pressed.
+    pub fn with_select_on_empty_submit(mut self) -> Self {
+        self.select_on_empty_submit = Some(true);
+        self
+    }
+
     /// Enables or disables vim_mode.
     pub fn with_vim_mode(mut self, vim_mode: bool) -> Self {
         self.vim_mode = vim_mode;

inquire/src/prompts/multiselect/prompt.rs

@@ -21,6 +21,7 @@ pub struct MultiSelectPrompt<'a, T> {
     options: Vec<T>,
     string_options: Vec<String>,
     help_message: Option<&'a str>,
+    select_on_empty_submit: Option<bool>,
     cursor_index: usize,
     checked: BTreeSet<usize>,
     input: Option<Input>,
@@ -80,6 +81,7 @@ where
             string_options,
             scored_options,
             help_message: mso.help_message,
+            select_on_empty_submit: mso.select_on_empty_submit,
             cursor_index: mso.starting_cursor,
             input,
             scorer: mso.scorer,
@@ -267,6 +269,12 @@ where
     }
 
     fn submit(&mut self) -> InquireResult<Option<Vec<ListOption<T>>>> {
+        if self.select_on_empty_submit.is_some_and(|ose| ose) && self.checked.is_empty() {
+            if let Some(idx) = self.scored_options.get(self.cursor_index) {
+                self.checked.insert(*idx);
+            };
+        }
+
         let answer = match self.validate_current_answer()? {
             Validation::Valid => Some(self.get_final_answer()),
             Validation::Invalid(msg) => {

inquire/src/prompts/multiselect/test.rs

@@ -301,3 +301,58 @@ fn first_option_renders_on_new_line_without_filtering() {
     match_text(&mut output, "\r");
     match_text(&mut output, "\n");
 }
+
+#[test]
+fn select_on_empty_submit_does_nothing_when_false() {
+    let mut backend = fake_backend(vec![
+        Key::Char('1', KeyModifiers::NONE), // filter to option 1
+        Key::Enter,
+    ]);
+
+    let options = vec![1, 2, 3, 4, 5];
+
+    let ans = MultiSelect::new("Question", options)
+        .prompt_with_backend(&mut backend)
+        .unwrap();
+
+    let expected_result = Vec::<ListOption<i32>>::new();
+    assert_eq!(expected_result, ans);
+}
+
+#[test]
+fn select_on_empty_submit_selects_option_under_cursor_when_true() {
+    let mut backend = fake_backend(vec![
+        Key::Char('1', KeyModifiers::NONE), // filter to option 1
+        Key::Enter,
+    ]);
+
+    let options = vec![1, 2, 3, 4, 5];
+
+    let ans = MultiSelect::new("Question", options)
+        .with_select_on_empty_submit()
+        .prompt_with_backend(&mut backend)
+        .unwrap();
+
+    let expected_result = vec![ListOption::new(0, 1)];
+    assert_eq!(expected_result, ans);
+}
+
+#[test]
+fn select_on_empty_submit_does_nothing_when_not_empty() {
+    let mut backend = fake_backend(vec![
+        Key::Char('2', KeyModifiers::NONE), // filter to option 2
+        Key::Char(' ', KeyModifiers::NONE), // toggle option 2 and reset filter
+        Key::Char('1', KeyModifiers::NONE), // filter to option 1
+        Key::Enter,
+    ]);
+
+    let options = vec![1, 2, 3, 4, 5];
+
+    let ans = MultiSelect::new("Question", options)
+        .with_select_on_empty_submit()
+        .prompt_with_backend(&mut backend)
+        .unwrap();
+
+    let expected_result = vec![ListOption::new(1, 2)];
+    assert_eq!(expected_result, ans);
+}