Refactor report generation and enhance integration tests

- Updated ReportService to streamline Excel report merging logic by introducing a new method for conditional merging.
- Enhanced integration tests to include fiscal period handling and ensure correct artifact generation, particularly for scenarios with empty forecast sections.
- Improved test assertions to validate the presence of expected artifacts and their properties in the generated reports.

server/api/src/main/java/com/hanwha/nexacrodemo/report/ReportService.java

@@ -201,11 +201,11 @@ public class ReportService {
         Row titleRow = sheet.createRow(0);
         titleRow.setHeightInPoints(24);
         createCell(titleRow, 0, sheetName + " Detail", styles.get("title"));
-        sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, Math.max(0, columnCount - 1)));
+        mergeIfNeeded(sheet, 0, columnCount);
 
         Row subtitleRow = sheet.createRow(1);
         createCell(subtitleRow, 0, "Fiscal period " + fiscalPeriod + " | Rows " + rows.size(), styles.get("subtitle"));
-        sheet.addMergedRegion(new CellRangeAddress(1, 1, 0, Math.max(0, columnCount - 1)));
+        mergeIfNeeded(sheet, 1, columnCount);
 
         if (rows.isEmpty()) {
             Row emptyRow = sheet.createRow(3);
@@ -347,6 +347,12 @@ public class ReportService {
         cell.setCellStyle(style);
     }
 
+    private void mergeIfNeeded(Sheet sheet, int rowIndex, int columnCount) {
+        if (columnCount > 1) {
+            sheet.addMergedRegion(new CellRangeAddress(rowIndex, rowIndex, 0, columnCount - 1));
+        }
+    }
+
     private CellStyle styleForKey(Map<String, CellStyle> styles, String key) {
         return key.toLowerCase().contains("ratio") ? styles.get("ratio") : styles.get("number");
     }

server/api/src/test/java/com/hanwha/nexacrodemo/consolidation/ConsolidationIntegrationTest.java

@@ -10,6 +10,7 @@ import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.hanwha.nexacrodemo.upload.TestWorkbookFactory;
 import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
 import org.apache.poi.ss.usermodel.WorkbookFactory;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
@@ -20,12 +21,14 @@ import org.springframework.http.MediaType;
 import org.springframework.mock.web.MockHttpSession;
 import org.springframework.mock.web.MockMultipartFile;
 import org.springframework.test.context.ActiveProfiles;
+import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.web.servlet.MockMvc;
 import org.springframework.test.web.servlet.MvcResult;
 
 @SpringBootTest
 @AutoConfigureMockMvc
 @ActiveProfiles("test")
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
 class ConsolidationIntegrationTest {
 
     @Autowired
@@ -39,24 +42,27 @@ class ConsolidationIntegrationTest {
 
     @Test
     void validUploadsCanBeConsolidatedAndReported() throws Exception {
+        String fiscalPeriod = "2026-04";
         MockHttpSession session = login("operator", "demo1234");
 
-        upload(session, "trial-balance", "tb-valid.xlsx", TestWorkbookFactory.trialBalanceValid());
+        upload(session, "trial-balance", fiscalPeriod, "tb-valid.xlsx", withFiscalPeriod(TestWorkbookFactory.trialBalanceValid(), fiscalPeriod));
-        upload(session, "forecast", "forecast-valid.xlsx", TestWorkbookFactory.forecastValid());
+        upload(session, "forecast", fiscalPeriod, "forecast-valid.xlsx", withFiscalPeriod(TestWorkbookFactory.forecastValid(), fiscalPeriod));
 
         MvcResult runResult = mockMvc.perform(post("/api/consolidations/runs")
                 .contentType(MediaType.APPLICATION_JSON)
                 .session(session)
                 .content("""
                     {
-                      "fiscalPeriod": "2026-03",
+                      "fiscalPeriod": "%s",
                       "reportCurrency": "KRW"
                     }
-                    """))
+                    """.formatted(fiscalPeriod)))
             .andExpect(status().isOk())
             .andExpect(jsonPath("$.statusCode").value("REQUESTED"))
             .andReturn();
 
+        long runId = objectMapper.readTree(runResult.getResponse().getContentAsByteArray()).path("id").asLong();
+
         consolidationService.processPendingRuns("test-worker");
 
         mockMvc.perform(get("/api/tx/consolidations/overview").session(session))
@@ -65,20 +71,24 @@ class ConsolidationIntegrationTest {
 
         MvcResult overviewResult = mockMvc.perform(get("/api/tx/reports/overview").session(session))
             .andExpect(status().isOk())
-            .andExpect(jsonPath("$.datasets.artifacts.length()").value(2))
             .andExpect(jsonPath("$.datasets.jobLogs[0].logLevel").exists())
             .andReturn();
 
         JsonNode artifacts = objectMapper.readTree(overviewResult.getResponse().getContentAsByteArray())
             .path("datasets")
             .path("artifacts");
+        int artifactCountForRun = 0;
         long excelArtifactId = -1L;
         for (JsonNode artifact : artifacts) {
+            if (artifact.path("runId").asLong() != runId) {
+                continue;
+            }
+            artifactCountForRun++;
             if ("EXCEL".equals(artifact.path("artifactType").asText())) {
                 excelArtifactId = artifact.path("id").asLong();
-                break;
             }
         }
+        Assertions.assertEquals(2, artifactCountForRun);
         Assertions.assertTrue(excelArtifactId > 0, "EXCEL artifact should exist");
 
         MvcResult excelDownload = mockMvc.perform(get("/api/reports/{artifactId}/download", excelArtifactId).session(session))
@@ -92,7 +102,61 @@ class ConsolidationIntegrationTest {
         }
     }
 
-    private void upload(MockHttpSession session, String templateCode, String fileName, byte[] content) throws Exception {
+    @Test
+    void consolidationStillSucceedsWhenForecastSectionIsEmpty() throws Exception {
+        String fiscalPeriod = "2026-03";
+        MockHttpSession session = login("operator", "demo1234");
+
+        upload(session, "trial-balance", fiscalPeriod, "tb-valid.xlsx", TestWorkbookFactory.trialBalanceValid());
+
+        MvcResult runResult = mockMvc.perform(post("/api/consolidations/runs")
+                .contentType(MediaType.APPLICATION_JSON)
+                .session(session)
+                .content("""
+                    {
+                      "fiscalPeriod": "%s",
+                      "reportCurrency": "KRW"
+                    }
+                    """.formatted(fiscalPeriod)))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.statusCode").value("REQUESTED"))
+            .andReturn();
+
+        long runId = objectMapper.readTree(runResult.getResponse().getContentAsByteArray()).path("id").asLong();
+
+        consolidationService.processPendingRuns("test-worker");
+
+        MvcResult overviewResult = mockMvc.perform(get("/api/tx/reports/overview").session(session))
+            .andExpect(status().isOk())
+            .andReturn();
+
+        JsonNode artifacts = objectMapper.readTree(overviewResult.getResponse().getContentAsByteArray())
+            .path("datasets")
+            .path("artifacts");
+        int artifactCountForRun = 0;
+        long excelArtifactId = -1L;
+        for (JsonNode artifact : artifacts) {
+            if (artifact.path("runId").asLong() != runId) {
+                continue;
+            }
+            artifactCountForRun++;
+            if ("EXCEL".equals(artifact.path("artifactType").asText())) {
+                excelArtifactId = artifact.path("id").asLong();
+            }
+        }
+        Assertions.assertEquals(2, artifactCountForRun);
+        Assertions.assertTrue(excelArtifactId > 0, "EXCEL artifact should exist");
+
+        MvcResult excelDownload = mockMvc.perform(get("/api/reports/{artifactId}/download", excelArtifactId).session(session))
+            .andExpect(status().isOk())
+            .andReturn();
+
+        try (var workbook = WorkbookFactory.create(new ByteArrayInputStream(excelDownload.getResponse().getContentAsByteArray()))) {
+            Assertions.assertEquals("No data available", workbook.getSheet("Forecast").getRow(3).getCell(0).getStringCellValue());
+        }
+    }
+
+    private void upload(MockHttpSession session, String templateCode, String fiscalPeriod, String fileName, byte[] content) throws Exception {
         MockMultipartFile file = new MockMultipartFile(
             "file",
             fileName,
@@ -103,12 +167,27 @@ class ConsolidationIntegrationTest {
         mockMvc.perform(multipart("/api/uploads")
                 .file(file)
                 .param("templateCode", templateCode)
-                .param("fiscalPeriod", "2026-03")
+                .param("fiscalPeriod", fiscalPeriod)
                 .session(session))
             .andExpect(status().isOk())
             .andExpect(jsonPath("$.statusCode").value("ACCEPTED"));
     }
 
+    private byte[] withFiscalPeriod(byte[] content, String fiscalPeriod) throws Exception {
+        try (var workbook = WorkbookFactory.create(new ByteArrayInputStream(content))) {
+            var dataSheet = workbook.getSheet("DATA");
+            for (int rowIndex = 1; rowIndex <= dataSheet.getLastRowNum(); rowIndex++) {
+                var row = dataSheet.getRow(rowIndex);
+                if (row != null && row.getCell(0) != null) {
+                    row.getCell(0).setCellValue(fiscalPeriod);
+                }
+            }
+            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+            workbook.write(outputStream);
+            return outputStream.toByteArray();
+        }
+    }
+
     private MockHttpSession login(String username, String password) throws Exception {
         MvcResult result = mockMvc.perform(post("/api/auth/login")
                 .contentType(MediaType.APPLICATION_JSON)