Add IT test

Needed to trigger filter pushdown.

Author: bpintea

x-pack/plugin/esql/qa/server/src/main/java/org/elasticsearch/xpack/esql/qa/rest/RestEsqlTestCase.java

@@ -1408,7 +1408,36 @@ public void testAsyncGetWithoutContentType() throws IOException {
                 .item(matchesMap().entry("name", "integer").entry("type", "integer")),
             values
         );
+    }
 
+    public void testReplaceStringCasingWithInsensitiveWildcardMatch() throws IOException {
+        createIndex(testIndexName(), Settings.EMPTY, """
+            {
+                "properties": {
+                    "reserved": {
+                        "type": "keyword"
+                    },
+                    "optional": {
+                        "type": "keyword"
+                    }
+                }
+            }
+            """);
+        Request doc = new Request("POST", testIndexName() + "/_doc?refresh=true");
+        doc.setJsonEntity("""
+            {
+                "reserved": "_\\"_$_(_)_+_._[_]_^_{_|_}___",
+                "optional": "_#_&_<_>___"
+            }
+            """);
+        client().performRequest(doc);
+        var query = "FROM " + testIndexName() + """
+            | WHERE TO_LOWER(reserved) LIKE "_\\"_$_(_)_+_._[_]_^_{_|_}*"
+            | WHERE TO_LOWER(optional) LIKE "_#_&_<_>*"
+            | KEEP reserved, optional
+            """;
+        var answer = runEsql(requestObjectBuilder().query(query));
+        assertThat(answer.get("values"), equalTo(List.of(List.of("_\"_$_(_)_+_._[_]_^_{_|_}___", "_#_&_<_>___"))));
     }
 
     protected static Request prepareRequestWithOptions(RequestObjectBuilder requestObject, Mode mode) throws IOException {