test: Add unit tests for Query class validation and equality behavior

spring-ai-rag/src/test/java/org/springframework/ai/rag/QueryTests.java

@@ -19,6 +19,7 @@
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
 
 /**
  * Unit tests for {@link Query}.
@@ -39,4 +40,42 @@ void whenTextIsEmptyThenThrow() {
 			.hasMessageContaining("text cannot be null or empty");
 	}
 
+	@Test
+	void whenTextIsBlankThenThrow() {
+		assertThatThrownBy(() -> new Query("   ")).isInstanceOf(IllegalArgumentException.class)
+			.hasMessageContaining("text cannot be null or empty");
+	}
+
+	@Test
+	void whenTextIsTabsAndSpacesThenThrow() {
+		assertThatThrownBy(() -> new Query("\t\n  \r")).isInstanceOf(IllegalArgumentException.class)
+			.hasMessageContaining("text cannot be null or empty");
+	}
+
+	@Test
+	void whenMultipleQueriesWithSameTextThenEqual() {
+		String text = "Same query text";
+		Query query1 = new Query(text);
+		Query query2 = new Query(text);
+
+		assertThat(query1).isEqualTo(query2);
+		assertThat(query1.hashCode()).isEqualTo(query2.hashCode());
+	}
+
+	@Test
+	void whenQueriesWithDifferentTextThenNotEqual() {
+		Query query1 = new Query("First query");
+		Query query2 = new Query("Second query");
+
+		assertThat(query1).isNotEqualTo(query2);
+		assertThat(query1.hashCode()).isNotEqualTo(query2.hashCode());
+	}
+
+	@Test
+	void whenCompareQueryToNullThenNotEqual() {
+		Query query = new Query("Test query");
+
+		assertThat(query).isNotEqualTo(null);
+	}
+
 }