From 0dae22d4383837258f3d226d1db7b46e8d1cb25d Mon Sep 17 00:00:00 2001
From: RobbingDaHood <16130319+RobbingDaHood@users.noreply.github.com>
Date: Wed, 18 Dec 2024 09:05:04 +0100
Subject: [PATCH] #10327 Now hashtags get parsed as comment starters if they
 are prefixed with any whitespace.

---
 crates/nu-parser/src/lex.rs        |  7 +++++--
 crates/nu-parser/tests/test_lex.rs | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/crates/nu-parser/src/lex.rs b/crates/nu-parser/src/lex.rs
index 6d1adf28ef..b808f6eacc 100644
--- a/crates/nu-parser/src/lex.rs
+++ b/crates/nu-parser/src/lex.rs
@@ -149,8 +149,11 @@ pub fn lex_item(
                 quote_start = None;
             }
         } else if c == b'#' && !in_comment {
-            // To start a comment, It either need to be the first character of the token or prefixed with space.
-            in_comment = previous_char.map(|pc| pc == b' ').unwrap_or(true);
+            // To start a comment, It either need to be the first character of the token or prefixed with whitespace.
+            in_comment = previous_char
+                .map(char::from)
+                .map(char::is_whitespace)
+                .unwrap_or(true);
         } else if c == b'\n' || c == b'\r' {
             in_comment = false;
             if is_item_terminator(&block_level, c, additional_whitespace, special_tokens) {
diff --git a/crates/nu-parser/tests/test_lex.rs b/crates/nu-parser/tests/test_lex.rs
index 54ff674bb9..2c1cf85bd8 100644
--- a/crates/nu-parser/tests/test_lex.rs
+++ b/crates/nu-parser/tests/test_lex.rs
@@ -182,6 +182,20 @@ fn lex_comment_with_space_in_front_of_hashtag() {
     ));
 }
 
+#[test]
+fn lex_comment_with_tab_in_front_of_hashtag() {
+    let file = b"1..10 | each {echo test\t#testing }";
+
+    let output = lex(file, 0, &[], &[], false);
+
+    assert!(output.1.is_some());
+    assert!(matches!(
+        output.1.unwrap(),
+        ParseError::UnexpectedEof(missing_token, span) if missing_token == "}"
+            && span == Span::new(33, 34)
+    ));
+}
+
 #[test]
 fn lex_is_incomplete() {
     let file = b"let x = 300 | ;";