complete test of Get product API endpoint

catalog-service/src/main/java/com/maxwell/catalog_service/domain/ProductNotFoundException.java

@@ -0,0 +1,10 @@
+package com.maxwell.catalog_service.domain;
+
+public class ProductNotFoundException extends RuntimeException {
+    public ProductNotFoundException(String message) {
+        super(message);
+    }
+    public static ProductNotFoundException forCode(String code) {
+        return new ProductNotFoundException("Product not found with code: " + code);
+    }
+}

catalog-service/src/main/java/com/maxwell/catalog_service/web/exception/GlobalExceptionHandler.java

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+package com.maxwell.catalog_service.web.exception;
+
+import com.maxwell.catalog_service.domain.ProductNotFoundException;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ProblemDetail;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+import java.net.URI;
+import java.time.Instant;
+
+@RestControllerAdvice
+class GlobalExceptionHandler extends ResponseEntityExceptionHandler {
+    private static final URI NOT_FOUND_TYPE = URI.create("https://api.bookstore.com/errors/not-found");
+    private static final URI ISE_FOUND_TYPE = URI.create("https://api.bookstore.com/errors/server-error");
+    private static final String SERVICE_NAME = "catalog-service";
+
+    @ExceptionHandler(Exception.class)
+    ProblemDetail handleUnhandledException(Exception e) {
+        ProblemDetail problemDetail =
+                ProblemDetail.forStatusAndDetail(HttpStatus.INTERNAL_SERVER_ERROR, e.getMessage());
+        problemDetail.setTitle("Internal Server Error");
+        problemDetail.setType(ISE_FOUND_TYPE);
+        problemDetail.setProperty("service", SERVICE_NAME);
+        problemDetail.setProperty("error_category", "Generic");
+        problemDetail.setProperty("timestamp", Instant.now());
+        return problemDetail;
+    }
+
+    @ExceptionHandler(ProductNotFoundException.class)
+    ProblemDetail handleProductNotFoundException(ProductNotFoundException e) {
+        ProblemDetail problemDetail = ProblemDetail.forStatusAndDetail(HttpStatus.NOT_FOUND, e.getMessage());
+        problemDetail.setTitle("Product Not Found");
+        problemDetail.setType(NOT_FOUND_TYPE);
+        problemDetail.setProperty("service", SERVICE_NAME);
+        problemDetail.setProperty("error_category", "Generic");
+        problemDetail.setProperty("timestamp", Instant.now());
+        return problemDetail;
+    }
+}

catalog-service/src/test/java/com/maxwell/catalog_service/domain/ProductRepositoryTest.java

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+package com.maxwell.catalog_service.domain;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.DynamicPropertyRegistry;
+import org.springframework.test.context.DynamicPropertySource;
+import org.springframework.test.context.jdbc.Sql;
+import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DataJpaTest
+@Testcontainers
+@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
+@Sql("/test-data.sql")
+class ProductRepositoryTest {
+
+        @Container
+        static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:16-alpine");
+
+        @DynamicPropertySource
+        static void configureProperties(DynamicPropertyRegistry registry) {
+                registry.add("spring.datasource.url", postgres::getJdbcUrl);
+                registry.add("spring.datasource.username", postgres::getUsername);
+                registry.add("spring.datasource.password", postgres::getPassword);
+        }
+
+        @Autowired
+        private ProductRepository productRepository;
+
+        @Test
+        void shouldGetProductByCode() {
+                ProductEntity product = productRepository.findByCode("P100").orElseThrow();
+                assertThat(product.getCode()).isEqualTo("P100");
+        }
+
+        @Test
+        void shouldReturnEmptyWhenProductCodeNotExists() {
+                assertThat(productRepository.findByCode("invalid_product_code")).isEmpty();
+        }
+}