1 files changed, 22 insertions, 1 deletions

diff --git a/crates/ra_editor/src/line_index.rs b/crates/ra_editor/src/line_index.rs
index 5304fbcf6..898fee7e0 100644
--- a/crates/ra_editor/src/line_index.rs
+++ b/crates/ra_editor/src/line_index.rs
@@ -128,8 +128,8 @@ impl LineIndex {
     }
 }
 
+#[cfg(test)]
 /// Simple reference implementation to use in proptests
-/// and benchmarks as baseline
 pub fn to_line_col(text: &str, offset: TextUnit) -> LineCol {
     let mut res = LineCol {
         line: 0,
@@ -270,6 +270,27 @@ mod test_line_index {
             .boxed()
     }
 
+    fn to_line_col(text: &str, offset: TextUnit) -> LineCol {
+        let mut res = LineCol {
+            line: 0,
+            col_utf16: 0,
+        };
+        for (i, c) in text.char_indices() {
+            if i + c.len_utf8() > offset.to_usize() {
+                // if it's an invalid offset, inside a multibyte char
+                // return as if it was at the start of the char
+                break;
+            }
+            if c == '\n' {
+                res.line += 1;
+                res.col_utf16 = 0;
+            } else {
+                res.col_utf16 += 1;
+            }
+        }
+        res
+    }
+
     proptest! {
         #[test]
         fn test_line_index_proptest((offset, text) in arb_text_with_offset()) {