From c23feeab3ae6b8e6c3c7106cda953041f8a4e487 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Tue, 28 Mar 2023 14:10:43 -0700
Subject: [PATCH] :art: Make expand_tabs and collapse_tabs instance methods on
 TabSnapshot

---
 crates/editor/src/display_map.rs         |  5 ++-
 crates/editor/src/display_map/tab_map.rs | 43 +++++++++++-------------
 2 files changed, 21 insertions(+), 27 deletions(-)

diff --git a/crates/editor/src/display_map.rs b/crates/editor/src/display_map.rs
index f49b9e34b8..cdf4b7e3ad 100644
--- a/crates/editor/src/display_map.rs
+++ b/crates/editor/src/display_map.rs
@@ -19,7 +19,7 @@ use std::{any::TypeId, fmt::Debug, num::NonZeroU32, ops::Range, sync::Arc};
 pub use suggestion_map::Suggestion;
 use suggestion_map::SuggestionMap;
 use sum_tree::{Bias, TreeMap};
-use tab_map::{TabMap, TabSnapshot};
+use tab_map::TabMap;
 use wrap_map::WrapMap;
 
 pub use block_map::{
@@ -637,7 +637,7 @@ impl DisplaySnapshot {
         let chars = buffer.chars_at(Point::new(range.start.row, 0));
 
         let mut is_blank = false;
-        let indent_size = TabSnapshot::expand_tabs(
+        let indent_size = self.tab_snapshot.expand_tabs(
             chars.take_while(|c| {
                 if *c == ' ' || *c == '\t' {
                     true
@@ -649,7 +649,6 @@ impl DisplaySnapshot {
                 }
             }),
             buffer.line_len(buffer_row) as usize, // Never collapse
-            self.tab_snapshot.tab_size,
         );
 
         (indent_size as u32, is_blank)
diff --git a/crates/editor/src/display_map/tab_map.rs b/crates/editor/src/display_map/tab_map.rs
index 45c92ea7b8..29dca3b1fb 100644
--- a/crates/editor/src/display_map/tab_map.rs
+++ b/crates/editor/src/display_map/tab_map.rs
@@ -245,7 +245,7 @@ impl TabSnapshot {
         let chars = self
             .suggestion_snapshot
             .chars_at(SuggestionPoint::new(input.row(), 0));
-        let expanded = Self::expand_tabs(chars, input.column() as usize, self.tab_size);
+        let expanded = self.expand_tabs(chars, input.column() as usize);
         TabPoint::new(input.row(), expanded as u32)
     }
 
@@ -259,7 +259,7 @@ impl TabSnapshot {
             .chars_at(SuggestionPoint::new(output.row(), 0));
         let expanded = output.column() as usize;
         let (collapsed, expanded_char_column, to_next_stop) =
-            Self::collapse_tabs(chars, expanded, bias, self.tab_size);
+            self.collapse_tabs(chars, expanded, bias);
         (
             SuggestionPoint::new(output.row(), collapsed as u32),
             expanded_char_column,
@@ -282,11 +282,9 @@ impl TabSnapshot {
         fold_point.to_buffer_point(&self.suggestion_snapshot.fold_snapshot)
     }
 
-    pub fn expand_tabs(
-        chars: impl Iterator<Item = char>,
-        column: usize,
-        tab_size: NonZeroU32,
-    ) -> usize {
+    pub fn expand_tabs(&self, chars: impl Iterator<Item = char>, column: usize) -> usize {
+        let tab_size = self.tab_size.get() as usize;
+
         let mut expanded_chars = 0;
         let mut expanded_bytes = 0;
         let mut collapsed_bytes = 0;
@@ -295,7 +293,6 @@ impl TabSnapshot {
                 break;
             }
             if c == '\t' {
-                let tab_size = tab_size.get() as usize;
                 let tab_len = tab_size - expanded_chars % tab_size;
                 expanded_bytes += tab_len;
                 expanded_chars += tab_len;
@@ -309,11 +306,13 @@ impl TabSnapshot {
     }
 
     fn collapse_tabs(
+        &self,
         chars: impl Iterator<Item = char>,
         column: usize,
         bias: Bias,
-        tab_size: NonZeroU32,
     ) -> (usize, usize, usize) {
+        let tab_size = self.tab_size.get() as usize;
+
         let mut expanded_bytes = 0;
         let mut expanded_chars = 0;
         let mut collapsed_bytes = 0;
@@ -323,7 +322,6 @@ impl TabSnapshot {
             }
 
             if c == '\t' {
-                let tab_size = tab_size.get() as usize;
                 let tab_len = tab_size - (expanded_chars % tab_size);
                 expanded_chars += tab_len;
                 expanded_bytes += tab_len;
@@ -508,20 +506,17 @@ mod tests {
     };
     use rand::{prelude::StdRng, Rng};
 
-    #[test]
-    fn test_expand_tabs() {
-        assert_eq!(
-            TabSnapshot::expand_tabs("\t".chars(), 0, 4.try_into().unwrap()),
-            0
-        );
-        assert_eq!(
-            TabSnapshot::expand_tabs("\t".chars(), 1, 4.try_into().unwrap()),
-            4
-        );
-        assert_eq!(
-            TabSnapshot::expand_tabs("\ta".chars(), 2, 4.try_into().unwrap()),
-            5
-        );
+    #[gpui::test]
+    fn test_expand_tabs(cx: &mut gpui::MutableAppContext) {
+        let buffer = MultiBuffer::build_simple("", cx);
+        let buffer_snapshot = buffer.read(cx).snapshot(cx);
+        let (_, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
+        let (_, suggestion_snapshot) = SuggestionMap::new(fold_snapshot);
+        let (_, tabs_snapshot) = TabMap::new(suggestion_snapshot, 4.try_into().unwrap());
+
+        assert_eq!(tabs_snapshot.expand_tabs("\t".chars(), 0), 0);
+        assert_eq!(tabs_snapshot.expand_tabs("\t".chars(), 1), 4);
+        assert_eq!(tabs_snapshot.expand_tabs("\ta".chars(), 2), 5);
     }
 
     #[gpui::test(iterations = 100)]