peng - Add test for verify the fix for parse and yamlIT

Signed-off-by: Jialiang Liang <jiallian@amazon.com>

Author: RyanL1997

integ-test/src/test/java/org/opensearch/sql/calcite/remote/CalciteParseCommandIT.java

@@ -5,6 +5,10 @@
 
 package org.opensearch.sql.calcite.remote;
 
+import static org.opensearch.sql.legacy.TestsConstants.TEST_INDEX_BANK;
+
+import java.io.IOException;
+import org.junit.Test;
 import org.opensearch.sql.ppl.ParseCommandIT;
 
 public class CalciteParseCommandIT extends ParseCommandIT {
@@ -13,4 +17,18 @@ public void init() throws Exception {
     super.init();
     enableCalcite();
   }
+
+  @Test
+  public void testParseErrorUnderscoreInGroupNames() throws IOException {
+    try {
+      executeQuery(
+          String.format(
+              "source=%s | parse email '.+@(?<host_name>.+)' | fields email", TEST_INDEX_BANK));
+      fail("Should have thrown an exception for underscore in named capture group");
+    } catch (Exception e) {
+      assertTrue(
+          e.getMessage()
+              .contains("Underscores are not permitted in Java Regex capture group names"));
+    }
+  }
 }

integ-test/src/yamlRestTest/resources/rest-api-spec/test/issues/3944.yml

@@ -0,0 +1,122 @@
+setup:
+  - do:
+      query.settings:
+        body:
+          transient:
+            plugins.calcite.enabled : true
+
+  - do:
+      indices.create:
+        index: accounts
+        body:
+          settings:
+            number_of_shards: 1
+            number_of_replicas: 0
+          mappings:
+            properties:
+              email:
+                type: text
+
+---
+teardown:
+  - do:
+      query.settings:
+        body:
+          transient:
+            plugins.calcite.enabled : false
+
+---
+"Enhanced error handling for underscores in rex regex capture group names":
+  - skip:
+      features:
+        - headers
+        - allowed_warnings
+  - do:
+      bulk:
+        index: accounts
+        refresh: true
+        body:
+          - '{"index": {}}'
+          - '{"email": "john@example.com"}'
+
+  - do:
+      catch: bad_request
+      headers:
+        Content-Type: 'application/json'
+      ppl:
+        body:
+          query: source=accounts | rex field=email ".+@(?<domain_name>.+)" | fields email, domain_name
+
+  - match: { $body: "{\n  \"error\": {\n    \"reason\": \"Invalid Query\",\n    \"details\": \"Underscores are not permitted in Java Regex capture group names\",\n    \"type\": \"IllegalArgumentException\"\n  },\n  \"status\": 400\n}" }
+
+---
+"Enhanced error handling for underscores in parse regex capture group names":
+  - skip:
+      features:
+        - headers
+        - allowed_warnings
+  - do:
+      bulk:
+        index: accounts
+        refresh: true
+        body:
+          - '{"index": {}}'
+          - '{"email": "john@example.com"}'
+
+  - do:
+      catch: bad_request
+      headers:
+        Content-Type: 'application/json'
+      ppl:
+        body:
+          query: source=accounts | parse email ".+@(?<host_name>.+)" | fields email, host_name
+
+  - match: { $body: "{\n  \"error\": {\n    \"reason\": \"Invalid Query\",\n    \"details\": \"Underscores are not permitted in Java Regex capture group names\",\n    \"type\": \"IllegalArgumentException\"\n  },\n  \"status\": 400\n}" }
+
+---
+"Rex command should work with valid group names without underscores":
+  - skip:
+      features:
+        - headers
+        - allowed_warnings
+  - do:
+      bulk:
+        index: accounts
+        refresh: true
+        body:
+          - '{"index": {}}'
+          - '{"email": "john@example.com"}'
+
+  - do:
+      headers:
+        Content-Type: 'application/json'
+      ppl:
+        body:
+          query: source=accounts | rex field=email ".+@(?<domain>.+)" | fields email, domain
+
+  - match: { total: 1 }
+  - match: { datarows: [["john@example.com", "example.com"]] }
+
+---
+"Parse command should work with valid group names without underscores":
+  - skip:
+      features:
+        - headers
+        - allowed_warnings
+  - do:
+      bulk:
+        index: accounts
+        refresh: true
+        body:
+          - '{"index": {}}'
+          - '{"email": "john@example.com"}'
+
+  - do:
+      headers:
+        Content-Type: 'application/json'
+      ppl:
+        body:
+          query: source=accounts | parse email ".+@(?<host>.+)" | fields email, host
+
+  - match: { total: 1 }
+  - match: { datarows: [["john@example.com", "example.com"]] }