test: cover regexp_replace multiline flag

datafusion/functions/src/regex/regexpreplace.rs

@@ -877,6 +877,25 @@ mod tests {
         i64
     );
 
+    #[test]
+    fn test_static_pattern_regexp_replace_multiline_flag() {
+        let values = StringArray::from(vec!["a\nb"]);
+        let patterns = StringArray::from(vec!["^b"]);
+        let replacements = StringArray::from(vec!["x"]);
+        let flags = StringArray::from(vec!["m"]);
+        let expected = StringArray::from(vec!["a\nx"]);
+
+        let re = regexp_replace_static_pattern_replace::<i32>(&[
+            Arc::new(values),
+            Arc::new(patterns),
+            Arc::new(replacements),
+            Arc::new(flags),
+        ])
+        .unwrap();
+
+        assert_eq!(re.as_ref(), &expected);
+    }
+
     #[test]
     fn test_static_pattern_regexp_replace_early_abort() {
         let values = StringArray::from(vec!["abc"; 5]);

datafusion/sqllogictest/test_files/regexp/regexp_replace.slt

@@ -113,6 +113,20 @@ SELECT regexp_replace('foobar', 'bar', 'xx', 'gi')
 ----
 fooxx
 
+query TT
+SELECT 'm', regexp_replace(concat('a', chr(10), 'b'), '^b', 'x', 'm')
+----
+m
+01)a
+02)x
+
+query TT
+SELECT 'gm', regexp_replace(concat('a', chr(10), 'b'), '^b', 'x', 'gm')
+----
+gm
+01)a
+02)x
+
 query T
 SELECT regexp_replace(arrow_cast('foobar', 'Dictionary(Int32, Utf8)'), 'bar', 'xx', 'gi')
 ----