test: add test case demonstrating projection issue with non-String fields

- Created test entity with mixed field types (Integer, Double, Boolean, LocalDate)
- Added projection interfaces with and without @value annotations
- Test shows that non-String fields require @value annotation to work properly
- The workaround of using @value annotation works as expected

This test documents the behavior described in issue #650 where projection
interfaces return null for non-String fields unless @value annotation is used.

Related to #650

Author: bsbodden

tests/src/test/java/com/redis/om/spring/fixtures/document/model/DocumentWithMixedTypes.java

@@ -0,0 +1,39 @@
+package com.redis.om.spring.fixtures.document.model;
+
+import com.redis.om.spring.annotations.Document;
+import com.redis.om.spring.annotations.Indexed;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.data.annotation.Id;
+
+import java.time.LocalDate;
+
+@Document
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Builder
+public class DocumentWithMixedTypes {
+
+  @Id
+  private String id;
+
+  @Indexed
+  private String name;
+
+  @Indexed
+  private Integer age;
+
+  @Indexed
+  private Double salary;
+
+  @Indexed
+  private Boolean active;
+
+  @Indexed
+  private LocalDate birthDate;
+
+  private String description;
+}

tests/src/test/java/com/redis/om/spring/fixtures/document/repository/DocumentMixedTypesProjection.java

@@ -0,0 +1,22 @@
+package com.redis.om.spring.fixtures.document.repository;
+
+import java.time.LocalDate;
+
+/**
+ * Projection interface WITHOUT @Value annotations to demonstrate the issue
+ * where non-String fields return null
+ */
+public interface DocumentMixedTypesProjection {
+  
+  // String fields should work without @Value
+  String getName();
+  
+  // Non-String fields will return null without @Value annotation
+  Integer getAge();
+  
+  Double getSalary();
+  
+  Boolean getActive();
+  
+  LocalDate getBirthDate();
+}

tests/src/test/java/com/redis/om/spring/fixtures/document/repository/DocumentMixedTypesProjectionFixed.java

@@ -0,0 +1,28 @@
+package com.redis.om.spring.fixtures.document.repository;
+
+import org.springframework.beans.factory.annotation.Value;
+
+import java.time.LocalDate;
+
+/**
+ * Projection interface WITH @Value annotations as a workaround
+ * to make non-String fields work correctly
+ */
+public interface DocumentMixedTypesProjectionFixed {
+  
+  // String fields work without @Value
+  String getName();
+  
+  // Non-String fields need @Value annotation to work
+  @Value("#{target.age}")
+  Integer getAge();
+  
+  @Value("#{target.salary}")
+  Double getSalary();
+  
+  @Value("#{target.active}")
+  Boolean getActive();
+  
+  @Value("#{target.birthDate}")
+  LocalDate getBirthDate();
+}

tests/src/test/java/com/redis/om/spring/fixtures/document/repository/DocumentMixedTypesRepository.java

@@ -0,0 +1,18 @@
+package com.redis.om.spring.fixtures.document.repository;
+
+import com.redis.om.spring.fixtures.document.model.DocumentWithMixedTypes;
+import com.redis.om.spring.repository.RedisDocumentRepository;
+
+import java.util.Optional;
+
+public interface DocumentMixedTypesRepository extends RedisDocumentRepository<DocumentWithMixedTypes, String> {
+  
+  // Return the entity first to verify data exists
+  Optional<DocumentWithMixedTypes> findByName(String name);
+  
+  // Return projection without @Value annotations
+  Optional<DocumentMixedTypesProjection> findFirstByName(String name);
+  
+  // Return projection with @Value annotations  
+  Optional<DocumentMixedTypesProjectionFixed> findOneByName(String name);
+}

tests/src/test/java/com/redis/om/spring/repository/DocumentProjectionMixedTypesTest.java

@@ -0,0 +1,110 @@
+package com.redis.om.spring.repository;
+
+import com.redis.om.spring.AbstractBaseDocumentTest;
+import com.redis.om.spring.fixtures.document.model.DocumentWithMixedTypes;
+import com.redis.om.spring.fixtures.document.repository.DocumentMixedTypesProjection;
+import com.redis.om.spring.fixtures.document.repository.DocumentMixedTypesProjectionFixed;
+import com.redis.om.spring.fixtures.document.repository.DocumentMixedTypesRepository;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.time.LocalDate;
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Test to reproduce and demonstrate issue #650:
+ * Projection interfaces return null for non-String fields when not using @Value annotation
+ */
+class DocumentProjectionMixedTypesTest extends AbstractBaseDocumentTest {
+
+  @Autowired
+  private DocumentMixedTypesRepository repository;
+
+  private DocumentWithMixedTypes testEntity;
+
+  @BeforeEach
+  void setUp() {
+    testEntity = DocumentWithMixedTypes.builder()
+        .name("John Doe")
+        .age(30)
+        .salary(75000.50)
+        .active(true)
+        .birthDate(LocalDate.of(1993, 5, 15))
+        .description("Test employee")
+        .build();
+    
+    testEntity = repository.save(testEntity);
+  }
+
+  @Test
+  void testEntityFetch_VerifyDataExists() {
+    // First verify the entity exists with proper data
+    Optional<DocumentWithMixedTypes> entity = repository.findByName("John Doe");
+    
+    assertTrue(entity.isPresent(), "Entity should be found by name");
+    assertEquals("John Doe", entity.get().getName());
+    assertEquals(30, entity.get().getAge());
+    assertEquals(75000.50, entity.get().getSalary());
+    assertTrue(entity.get().getActive());
+    assertEquals(LocalDate.of(1993, 5, 15), entity.get().getBirthDate());
+  }
+
+  @Test
+  void testProjectionWithoutValueAnnotation_NonStringFieldsReturnNull() {
+    // This test demonstrates the issue - non-String fields return null without @Value
+    Optional<DocumentMixedTypesProjection> projection = repository.findFirstByName("John Doe");
+    
+    assertTrue(projection.isPresent(), "Projection should be present");
+    
+    // String field should work
+    assertEquals("John Doe", projection.get().getName(), "String field should work without @Value");
+    
+    // These assertions demonstrate the issue - all non-String fields return null
+    assertNull(projection.get().getAge(), 
+        "Integer field returns null without @Value annotation - this is the issue!");
+    assertNull(projection.get().getSalary(), 
+        "Double field returns null without @Value annotation - this is the issue!");
+    assertNull(projection.get().getActive(), 
+        "Boolean field returns null without @Value annotation - this is the issue!");
+    assertNull(projection.get().getBirthDate(), 
+        "LocalDate field returns null without @Value annotation - this is the issue!");
+  }
+
+  @Test
+  void testProjectionWithValueAnnotation_AllFieldsWork() {
+    // Test that all fields work correctly with @Value annotation (the workaround)
+    Optional<DocumentMixedTypesProjectionFixed> projection = repository.findOneByName("John Doe");
+    
+    assertTrue(projection.isPresent(), "Projection should be present");
+    
+    // All fields should work with @Value annotation
+    assertEquals("John Doe", projection.get().getName(), "String field should work");
+    assertEquals(30, projection.get().getAge(), "Integer field should work with @Value");
+    assertEquals(75000.50, projection.get().getSalary(), "Double field should work with @Value");
+    assertTrue(projection.get().getActive(), "Boolean field should work with @Value");
+    assertEquals(LocalDate.of(1993, 5, 15), projection.get().getBirthDate(), 
+        "LocalDate field should work with @Value");
+  }
+
+  @Test
+  void testDirectEntityFetch_AllFieldsWork() {
+    // Verify that the entity itself has all fields correctly stored
+    Optional<DocumentWithMixedTypes> entity = repository.findById(testEntity.getId());
+    
+    assertTrue(entity.isPresent(), "Entity should be present");
+    assertEquals("John Doe", entity.get().getName());
+    assertEquals(30, entity.get().getAge());
+    assertEquals(75000.50, entity.get().getSalary());
+    assertTrue(entity.get().getActive());
+    assertEquals(LocalDate.of(1993, 5, 15), entity.get().getBirthDate());
+  }
+
+  @AfterEach
+  void tearDown() {
+    repository.deleteAll();
+  }
+}