more alignment

Author: Brooooooklyn

crates/oxc_angular_compiler/src/parser/html/whitespace.rs

@@ -47,20 +47,48 @@ fn has_non_whitespace(s: &str) -> bool {
     s.chars().any(|c| !is_ws_char(c))
 }
 
-/// Replace consecutive whitespace with a single space.
+/// Replace runs of 2+ consecutive whitespace characters with a single space.
+/// Single whitespace characters are preserved as-is.
 fn collapse_whitespace(s: &str) -> String {
     let mut result = String::with_capacity(s.len());
-    let mut prev_ws = false;
+    let mut ws_run_start: Option<usize> = None;
+    let mut ws_run_len = 0;
 
-    for c in s.chars() {
+    for (i, c) in s.chars().enumerate() {
         if is_ws_char(c) {
-            if !prev_ws {
-                result.push(' ');
-                prev_ws = true;
+            if ws_run_start.is_none() {
+                ws_run_start = Some(i);
             }
+            ws_run_len += 1;
         } else {
+            // End of whitespace run (if any)
+            if let Some(_start) = ws_run_start {
+                if ws_run_len >= 2 {
+                    // Replace 2+ whitespace chars with single space
+                    result.push(' ');
+                } else {
+                    // Keep single whitespace char as-is
+                    // We need to get the original char
+                    if let Some(ws_char) = s.chars().nth(i - 1) {
+                        result.push(ws_char);
+                    }
+                }
+                ws_run_start = None;
+                ws_run_len = 0;
+            }
             result.push(c);
-            prev_ws = false;
+        }
+    }
+
+    // Handle trailing whitespace
+    if let Some(start) = ws_run_start {
+        if ws_run_len >= 2 {
+            result.push(' ');
+        } else {
+            // Keep single trailing whitespace char as-is
+            if let Some(ws_char) = s.chars().nth(start) {
+                result.push(ws_char);
+            }
         }
     }
 
@@ -722,9 +750,17 @@ mod tests {
 
     #[test]
     fn test_collapse_whitespace() {
+        // Multiple consecutive whitespace -> single space
         assert_eq!(collapse_whitespace("a  b"), "a b");
         assert_eq!(collapse_whitespace("a\n\n\tb"), "a b");
         assert_eq!(collapse_whitespace("  a  "), " a ");
+
+        // Single whitespace characters are preserved as-is
+        assert_eq!(collapse_whitespace("\n"), "\n");
+        assert_eq!(collapse_whitespace("a\nb"), "a\nb");
+        assert_eq!(collapse_whitespace(" "), " ");
+        assert_eq!(collapse_whitespace("\t"), "\t");
+        assert_eq!(collapse_whitespace("a b"), "a b");
     }
 
     #[test]