const response = await this.page.evaluate(async ({ url, headers, orgId, streamName, logData }) => {
-    const fetchResponse = await fetch(`${url}/api/${orgId}/${streamName}/_json`, {
-        method: 'POST',
-        headers: headers,
-        body: JSON.stringify(logData)
-    });
-    return await fetchResponse.json();
+    try {
+        const fetchResponse = await fetch(`${url}/api/${orgId}/${streamName}/_json`, {
+            method: 'POST',
+            headers,
+            body: JSON.stringify(logData)
+        });
+        const body = await fetchResponse.text();
+        return { ok: fetchResponse.ok, status: fetchResponse.status, body };
+    } catch (err) {
+        return { ok: false, status: 0, body: String(err) };
+    }
 }, {
     url: process.env.INGESTION_URL,
-    headers: headers,
-    orgId: orgId,
-    streamName: streamName,
-    logData: logData
+    headers,
+    orgId,
+    streamName,
+    logData
 });

 async verifyDownload(download, expectedFileName, downloadDir) {
     const downloadPath = path.join(downloadDir, expectedFileName);
-    
-    // Save the download
     await download.saveAs(downloadPath);
-    
-    // Wait for file system to sync
-    await new Promise(resolve => setTimeout(resolve, 1000));
-    
-    // Verify file exists and has content
+    // Ensure download completed successfully
+    const failure = await download.failure();
+    expect(failure).toBeNull();
+    // Ensure the file is fully written before reading
+    const resolvedPath = await download.path();
+    expect(resolvedPath).toBeTruthy();
     expect(fs.existsSync(downloadPath)).toBe(true);
     const stats = fs.statSync(downloadPath);
     expect(stats.size).toBeGreaterThan(0);
-    
-    // Verify it's a CSV file
     const content = fs.readFileSync(downloadPath, 'utf8');
     expect(content).toContain('_timestamp');
-    ...
+    const rows = content.split('\n').filter(line => line.trim() !== '');
+    const rowCount = rows.length - 1;
+    console.log(`Download ${expectedFileName}: ${rowCount} data rows`);
+    if (expectedFileName.includes('custom_100.csv')) {
+        expect(rowCount).toBe(100);
+    } else if (expectedFileName.includes('custom_500.csv')) {
+        expect(rowCount).toBe(500);
+    } else if (expectedFileName.includes('custom_1000.csv')) {
+        expect(rowCount).toBe(1000);
+    } else if (expectedFileName.includes('custom_5000.csv')) {
+        expect(rowCount).toBe(5000);
+    } else if (expectedFileName.includes('custom_10000.csv')) {
+        expect(rowCount).toBe(10000);
+    } else if (expectedFileName.includes('sql_limit_2000.csv')) {
+        expect(rowCount).toBe(2000);
+    } else if (expectedFileName.includes('sql_limit_2000_custom_500.csv')) {
+        expect(rowCount).toBe(500);
+    } else {
+        expect(rowCount).toBeGreaterThan(0);
+    }
+    return downloadPath;
 }

 async clearQueryEditor() {
-    return await this.page.locator(this.queryEditor).getByRole('textbox').press('ControlOrMeta+a');
+    const textbox = this.page.locator(this.queryEditor).getByRole('textbox');
+    await textbox.press('ControlOrMeta+a');
+    await textbox.press('Backspace');
 }