fix: Fuzzy completion with Unicode chars

src/menu/columnar_menu.rs

@@ -1,11 +1,12 @@
-use super::{Menu, MenuBuilder, MenuEvent, MenuSettings};
+use super::{menu_functions::split_suggestion, Menu, MenuBuilder, MenuEvent, MenuSettings};
 use crate::{
     core_editor::Editor,
     menu_functions::{can_partially_complete, completer_input, replace_in_buffer},
     painting::Painter,
     Completer, Suggestion,
 };
 use nu_ansi_term::ansi::RESET;
+use unicode_segmentation::UnicodeSegmentation;
 use unicode_width::UnicodeWidthStr;
 
 /// Default values used as reference for the menu. These values are set during
@@ -38,8 +39,8 @@ struct ColumnDetails {
     pub columns: u16,
     /// Column width
     pub col_width: usize,
-    /// The shortest of the strings, which the suggestions are based on
-    pub shortest_base_string: String,
+    /// Number of graphemes in the shortest string, which the suggestions are based on
+    pub match_len: usize,
 }
 
 /// Menu to present suggestions in a columnar fashion
@@ -299,23 +300,8 @@ impl ColumnarMenu {
         use_ansi_coloring: bool,
     ) -> String {
         if use_ansi_coloring {
-            // strip quotes
-            let is_quote = |c: char| "`'\"".contains(c);
-            let shortest_base = &self.working_details.shortest_base_string;
-            let shortest_base = shortest_base
-                .strip_prefix(is_quote)
-                .unwrap_or(shortest_base);
-            let match_len = shortest_base.len();
-
-            // Split string so the match text can be styled
-            let skip_len = suggestion
-                .value
-                .chars()
-                .take_while(|c| is_quote(*c))
-                .count();
-            let (match_str, remaining_str) = suggestion
-                .value
-                .split_at((match_len + skip_len).min(suggestion.value.len()));
+            let (match_str, remaining_str) =
+                split_suggestion(&suggestion.value, self.working_details.match_len);
 
             let suggestion_style_prefix = suggestion
                 .style
@@ -510,10 +496,16 @@ impl Menu for ColumnarMenu {
         let (values, base_ranges) = completer.complete_with_base_ranges(&input, pos);
 
         self.values = values;
-        self.working_details.shortest_base_string = base_ranges
+        self.working_details.match_len = base_ranges
             .iter()
-            .map(|range| editor.get_buffer()[range.clone()].to_string())
-            .min_by_key(|s| s.width())
+            .map(|range| {
+                let s = &editor.get_buffer()[range.clone()];
+                s.strip_prefix(['`', '\'', '"'])
+                    .unwrap_or(s)
+                    .graphemes(true)
+                    .count()
+            })
+            .min()
             .unwrap_or_default();
 
         self.reset_position();

src/menu/ide_menu.rs

@@ -1,4 +1,4 @@
-use super::{Menu, MenuBuilder, MenuEvent, MenuSettings};
+use super::{menu_functions::split_suggestion, Menu, MenuBuilder, MenuEvent, MenuSettings};
 use crate::{
     core_editor::Editor,
     menu_functions::{can_partially_complete, completer_input, replace_in_buffer},
@@ -125,8 +125,8 @@ struct IdeMenuDetails {
     pub space_right: u16,
     /// Corrected description offset, based on the available space
     pub description_offset: u16,
-    /// The shortest of the strings, which the suggestions are based on
-    pub shortest_base_string: String,
+    /// Number of graphemes in the shortest string, which the suggestions are based on
+    pub match_len: usize,
 }
 
 /// Menu to present suggestions like similar to Ide completion menus
@@ -512,18 +512,8 @@ impl IdeMenu {
         };
 
         if use_ansi_coloring {
-            // strip quotes
-            let is_quote = |c: char| "`'\"".contains(c);
-            let shortest_base = &self.working_details.shortest_base_string;
-            let shortest_base = shortest_base
-                .strip_prefix(is_quote)
-                .unwrap_or(shortest_base);
-            let match_len = shortest_base.len().min(string.len());
-
-            // Split string so the match text can be styled
-            let skip_len = string.chars().take_while(|c| is_quote(*c)).count();
             let (match_str, remaining_str) =
-                string.split_at((match_len + skip_len).min(string.len()));
+                split_suggestion(&suggestion.value, self.working_details.match_len);
 
             let suggestion_style_prefix = suggestion
                 .style
@@ -642,10 +632,16 @@ impl Menu for IdeMenu {
         let (values, base_ranges) = completer.complete_with_base_ranges(&input, pos);
 
         self.values = values;
-        self.working_details.shortest_base_string = base_ranges
+        self.working_details.match_len = base_ranges
             .iter()
-            .map(|range| editor.get_buffer()[range.clone()].to_string())
-            .min_by_key(|s| s.len())
+            .map(|range| {
+                let s = &editor.get_buffer()[range.clone()];
+                s.strip_prefix(['`', '\'', '"'])
+                    .unwrap_or(s)
+                    .graphemes(true)
+                    .count()
+            })
+            .min()
             .unwrap_or_default();
 
         self.reset_position();
@@ -703,9 +699,7 @@ impl Menu for IdeMenu {
             let mut cursor_pos = self.working_details.cursor_col;
 
             if self.default_details.correct_cursor_pos {
-                let base_string = &self.working_details.shortest_base_string;
-
-                cursor_pos = cursor_pos.saturating_sub(base_string.width() as u16);
+                cursor_pos = cursor_pos.saturating_sub(self.working_details.match_len as u16);
             }
 
             let border_width = if self.default_details.border.is_some() {
@@ -1432,7 +1426,7 @@ mod tests {
             space_left: 50,
             space_right: 50,
             description_offset: 50,
-            shortest_base_string: String::new(),
+            match_len: 0,
         };
         let mut editor = Editor::default();
         // backtick at the end of the line
@@ -1460,7 +1454,7 @@ mod tests {
             space_left: 50,
             space_right: 50,
             description_offset: 50,
-            shortest_base_string: String::new(),
+            match_len: 0,
         };
         let mut editor = Editor::default();
 

src/menu/menu_functions.rs

@@ -1,4 +1,6 @@
 //! Collection of common functions that can be used to create menus
+use unicode_segmentation::UnicodeSegmentation;
+
 use crate::{Editor, Suggestion, UndoBehavior};
 
 /// Index result obtained from parsing a string with an index marker
@@ -354,6 +356,27 @@ pub fn can_partially_complete(values: &[Suggestion], editor: &mut Editor) -> boo
     }
 }
 
+/// Split suggestion based on number of graphemes in shortest matched string
+///
+/// For highlighting prefix-matched suggestions
+pub fn split_suggestion(sugg: &str, match_len: usize) -> (&str, &str) {
+    let mut graphemes = sugg.grapheme_indices(true).peekable();
+    let Some((_, first)) = graphemes.peek() else {
+        return ("", "");
+    };
+    let skip = if match_len > 0 && (*first == "`" || *first == "'" || *first == "\"") {
+        1 + match_len
+    } else {
+        match_len
+    };
+
+    if let Some((ind, _)) = graphemes.nth(skip) {
+        sugg.split_at(ind)
+    } else {
+        (sugg, "")
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -697,4 +720,27 @@ mod tests {
         assert_eq!(orig_buffer, editor.get_buffer());
         assert_eq!(orig_insertion_point, editor.insertion_point());
     }
+
+    #[rstest]
+    #[case("おはよう", "おは", "おは")]
+    #[case("`'おはよう)", "'お", "`'お")]
+    #[case("'a", "", "")]
+    #[case("おはよう", "a", "お")]
+    #[case("abcd", "お", "a")]
+    fn test_split_suggestions(
+        #[case] sugg: &str,
+        #[case] typed: &str,
+        #[case] exp_match_str: &str,
+    ) {
+        let (got_match_str, _) = split_suggestion(sugg, typed.graphemes(true).count());
+        assert_eq!(exp_match_str, got_match_str)
+    }
+
+    #[test]
+    fn test_split_suggestions_shorter_than_typed() {
+        let sugg = "a";
+        let typed = "abcd";
+        let (got_match_str, _) = split_suggestion(sugg, typed.graphemes(true).count());
+        assert_eq!("a", got_match_str)
+    }
 }