fix invalid escape sequence at end of file, sort messages by kind

crates/ruff/src/message/mod.rs

@@ -25,6 +25,7 @@ pub use pylint::PylintEmitter;
 pub use text::TextEmitter;
 
 use crate::jupyter::JupyterIndex;
+use crate::registry::AsRule;
 use ruff_diagnostics::{Diagnostic, DiagnosticKind, Fix};
 use ruff_python_ast::source_code::{SourceFile, SourceLocation};
 
@@ -75,7 +76,11 @@ impl Message {
 
 impl Ord for Message {
     fn cmp(&self, other: &Self) -> Ordering {
-        (self.filename(), self.start()).cmp(&(other.filename(), other.start()))
+        (self.filename(), self.start(), self.kind.rule()).cmp(&(
+            other.filename(),
+            other.start(),
+            other.kind.rule(),
+        ))
     }
 }
 

crates/ruff/src/rules/pycodestyle/rules/invalid_escape_sequence.rs

@@ -89,10 +89,15 @@ pub fn invalid_escape_sequence(
                 continue;
             }
 
-            // If we're at the end of the line, skip.
+            // If we're at the end of the file, skip.
             let Some((_, next_char)) = chars_iter.peek() else {
-                    continue;
-                };
+                continue;
+            };
+
+            // If we're at the end of the line, skip
+            if matches!(next_char, '\n' | '\r') {
+                continue;
+            }
 
             // If the next character is a valid escape sequence, skip.
             if VALID_ESCAPE_SEQUENCES.contains(next_char) {