peng - add more IT for highlight cases

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

Author: RyanL1997

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

@@ -213,6 +213,67 @@ public void testHighlightWithStats() throws IOException {
     assertTrue("Response should contain datarows", result.has("datarows"));
   }
 
+  @Test
+  public void testHighlightBooleanOrSearch() throws IOException {
+    JSONObject result =
+        executeQueryWithHighlight(
+            "source=" + TEST_INDEX_ACCOUNT + " \"Holmes\" OR \"Bond\"", "[\"*\"]");
+    JSONArray dataRows = result.getJSONArray("datarows");
+    assertTrue("OR search should return results", dataRows.length() > 0);
+    assertHighlightsExist(result);
+    // Verify highlights contain fragments for both search terms
+    JSONArray highlights = result.getJSONArray("highlights");
+    boolean foundHolmes = false;
+    boolean foundBond = false;
+    for (int i = 0; i < highlights.length(); i++) {
+      String hlStr = highlights.getJSONObject(i).toString();
+      if (hlStr.contains("Holmes")) foundHolmes = true;
+      if (hlStr.contains("Bond")) foundBond = true;
+    }
+    assertTrue("Highlights should contain Holmes fragments", foundHolmes);
+    assertTrue("Highlights should contain Bond fragments", foundBond);
+  }
+
+  @Test
+  public void testHighlightBooleanAndSearch() throws IOException {
+    JSONObject result =
+        executeQueryWithHighlight(
+            "source=" + TEST_INDEX_ACCOUNT + " \"Holmes\" AND \"Lane\"", "[\"*\"]");
+    JSONArray dataRows = result.getJSONArray("datarows");
+    assertTrue("AND search should return results", dataRows.length() > 0);
+    assertHighlightsExist(result);
+    // Verify highlights contain fragments for both terms
+    JSONArray highlights = result.getJSONArray("highlights");
+    boolean foundHolmes = false;
+    boolean foundLane = false;
+    for (int i = 0; i < highlights.length(); i++) {
+      String hlStr = highlights.getJSONObject(i).toString();
+      if (hlStr.contains("Holmes")) foundHolmes = true;
+      if (hlStr.contains("Lane")) foundLane = true;
+    }
+    assertTrue("Highlights should contain Holmes fragments", foundHolmes);
+    assertTrue("Highlights should contain Lane fragments", foundLane);
+  }
+
+  @Test
+  public void testHighlightNotSearch() throws IOException {
+    // NOT queries negate the match — the query succeeds but highlights are empty
+    // because there are no positive matches to highlight
+    JSONObject result =
+        executeQueryWithHighlight("source=" + TEST_INDEX_ACCOUNT + " NOT \"Holmes\"", "[\"*\"]");
+    JSONArray dataRows = result.getJSONArray("datarows");
+    assertTrue("NOT search should return results", dataRows.length() > 0);
+  }
+
+  @Test
+  public void testHighlightBooleanOrWithFilter() throws IOException {
+    JSONObject result =
+        executeQueryWithHighlight(
+            "source=" + TEST_INDEX_ACCOUNT + " \"Holmes\" OR \"Bond\" | where age > 30", "[\"*\"]");
+    assertTrue("Response should contain datarows", result.has("datarows"));
+    assertHighlightsExist(result);
+  }
+
   @Test
   public void testHighlightNoSearchQuery() throws IOException {
     // Without a search query, request should still succeed (highlights may or may not be present)

ppl/src/test/java/org/opensearch/sql/ppl/domain/PPLQueryRequestTest.java

@@ -8,6 +8,7 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 
 import java.util.List;
@@ -198,4 +199,87 @@ public void testGetHighlightConfigPerFieldOptions() {
     assertEquals(3, config.fields().get("title").get("number_of_fragments"));
     assertEquals("plain", config.fields().get("body").get("type"));
   }
+
+  @Test
+  public void testGetHighlightConfigEmptyFieldNameThrows() {
+    JSONObject json = new JSONObject("{\"query\": \"source=t\", \"highlight\": [\"\"]}");
+    PPLQueryRequest request = new PPLQueryRequest("source=t", json, "/_plugins/_ppl");
+    IllegalArgumentException e =
+        assertThrows(IllegalArgumentException.class, request::getHighlightConfig);
+    assertTrue(e.getMessage().contains("non-empty"));
+  }
+
+  @Test
+  public void testGetHighlightConfigNegativeFragmentSizeThrows() {
+    JSONObject json =
+        new JSONObject(
+            "{\"query\": \"source=t\", \"highlight\": {"
+                + "\"fields\": {\"*\": {}}, \"fragment_size\": -1}}");
+    PPLQueryRequest request = new PPLQueryRequest("source=t", json, "/_plugins/_ppl");
+    IllegalArgumentException e =
+        assertThrows(IllegalArgumentException.class, request::getHighlightConfig);
+    assertTrue(e.getMessage().contains("fragment_size must be a positive integer"));
+  }
+
+  @Test
+  public void testGetHighlightConfigZeroFragmentSizeThrows() {
+    JSONObject json =
+        new JSONObject(
+            "{\"query\": \"source=t\", \"highlight\": {"
+                + "\"fields\": {\"*\": {}}, \"fragment_size\": 0}}");
+    PPLQueryRequest request = new PPLQueryRequest("source=t", json, "/_plugins/_ppl");
+    IllegalArgumentException e =
+        assertThrows(IllegalArgumentException.class, request::getHighlightConfig);
+    assertTrue(e.getMessage().contains("fragment_size must be a positive integer"));
+  }
+
+  @Test
+  public void testGetHighlightConfigExceedMaxFieldsArrayThrows() {
+    // Build an array with 101 fields
+    StringBuilder sb = new StringBuilder("{\"query\": \"source=t\", \"highlight\": [");
+    for (int i = 0; i < 101; i++) {
+      if (i > 0) sb.append(",");
+      sb.append("\"field").append(i).append("\"");
+    }
+    sb.append("]}");
+    JSONObject json = new JSONObject(sb.toString());
+    PPLQueryRequest request = new PPLQueryRequest("source=t", json, "/_plugins/_ppl");
+    IllegalArgumentException e =
+        assertThrows(IllegalArgumentException.class, request::getHighlightConfig);
+    assertTrue(e.getMessage().contains("fields count exceeds maximum"));
+  }
+
+  @Test
+  public void testGetHighlightConfigExceedMaxFieldsObjectThrows() {
+    // Build an object with 101 fields
+    StringBuilder sb = new StringBuilder("{\"query\": \"source=t\", \"highlight\": {\"fields\": {");
+    for (int i = 0; i < 101; i++) {
+      if (i > 0) sb.append(",");
+      sb.append("\"field").append(i).append("\": {}");
+    }
+    sb.append("}}}");
+    JSONObject json = new JSONObject(sb.toString());
+    PPLQueryRequest request = new PPLQueryRequest("source=t", json, "/_plugins/_ppl");
+    IllegalArgumentException e =
+        assertThrows(IllegalArgumentException.class, request::getHighlightConfig);
+    assertTrue(e.getMessage().contains("fields count exceeds maximum"));
+  }
+
+  @Test
+  public void testGetHighlightConfigExceedMaxTagsThrows() {
+    // Build pre_tags array with 11 entries
+    StringBuilder sb =
+        new StringBuilder(
+            "{\"query\": \"source=t\", \"highlight\": {\"fields\": {\"*\": {}}, \"pre_tags\": [");
+    for (int i = 0; i < 11; i++) {
+      if (i > 0) sb.append(",");
+      sb.append("\"tag").append(i).append("\"");
+    }
+    sb.append("]}}");
+    JSONObject json = new JSONObject(sb.toString());
+    PPLQueryRequest request = new PPLQueryRequest("source=t", json, "/_plugins/_ppl");
+    IllegalArgumentException e =
+        assertThrows(IllegalArgumentException.class, request::getHighlightConfig);
+    assertTrue(e.getMessage().contains("pre_tags count exceeds maximum"));
+  }
 }