fix(scanner): preserve message count in light metadata

src/main/services/discovery/ProjectScanner.ts

@@ -39,11 +39,7 @@ import {
   type SessionsPaginationOptions,
   type WorktreeSource,
 } from '@main/types';
-import {
-  analyzeSessionFileMetadata,
-  extractCwd,
-  extractFirstUserMessagePreview,
-} from '@main/utils/jsonl';
+import { analyzeSessionFileMetadata, extractCwd } from '@main/utils/jsonl';
 import {
   buildSessionPath,
   buildSubagentsPath,
@@ -1035,20 +1031,30 @@ export class ProjectScanner {
     const effectiveMtime = prefetchedMtimeMs ?? stats?.mtimeMs ?? Date.now();
     const effectiveSize = prefetchedSize ?? stats?.size ?? -1;
     const birthtimeMs = prefetchedBirthtimeMs ?? stats?.birthtimeMs ?? effectiveMtime;
-    const cachedPreview = this.sessionPreviewCache.get(filePath);
-    const preview =
-      cachedPreview?.mtimeMs === effectiveMtime && cachedPreview.size === effectiveSize
-        ? cachedPreview.preview
-        : await this.extractLightPreviewWithRetry(filePath);
-    if (cachedPreview?.mtimeMs !== effectiveMtime || cachedPreview.size !== effectiveSize) {
-      this.sessionPreviewCache.set(filePath, {
-        mtimeMs: effectiveMtime,
-        size: effectiveSize,
-        preview,
-      });
+    let metadata: Awaited<ReturnType<typeof analyzeSessionFileMetadata>>;
+    const cachedMetadata = this.sessionMetadataCache.get(filePath);
+    if (cachedMetadata?.mtimeMs === effectiveMtime && cachedMetadata.size === effectiveSize) {
+      metadata = cachedMetadata.metadata;
+    } else {
+      try {
+        metadata = await analyzeSessionFileMetadata(filePath, this.fsProvider);
+        this.sessionMetadataCache.set(filePath, {
+          mtimeMs: effectiveMtime,
+          size: effectiveSize,
+          metadata,
+        });
+      } catch (error) {
+        logger.debug(`Failed to analyze session metadata for ${filePath}:`, error);
+        metadata = {
+          firstUserMessage: null,
+          messageCount: 0,
+          isOngoing: false,
+          gitBranch: null,
+        };
+      }
     }
     const metadataLevel: SessionMetadataLevel = 'light';
-    const previewTimestampMs = this.parseTimestampMs(preview?.timestamp);
+    const previewTimestampMs = this.parseTimestampMs(metadata.firstUserMessage?.timestamp);
     const createdAt =
       previewTimestampMs !== null && Number.isFinite(previewTimestampMs)
         ? previewTimestampMs
@@ -1059,10 +1065,10 @@ export class ProjectScanner {
       projectId,
       projectPath,
       createdAt: Math.floor(createdAt),
-      firstMessage: preview?.text,
-      messageTimestamp: preview?.timestamp,
+      firstMessage: metadata.firstUserMessage?.text,
+      messageTimestamp: metadata.firstUserMessage?.timestamp,
       hasSubagents: false,
-      messageCount: 0,
+      messageCount: metadata.messageCount,
       metadataLevel,
     };
   }
@@ -1459,31 +1465,6 @@ export class ProjectScanner {
     return results;
   }
 
-  private async extractLightPreviewWithRetry(
-    filePath: string
-  ): Promise<{ text: string; timestamp: string } | null> {
-    const maxAttempts = this.fsProvider.type === 'ssh' ? 3 : 1;
-    let lastError: unknown;
-
-    for (let attempt = 1; attempt <= maxAttempts; attempt++) {
-      try {
-        return await extractFirstUserMessagePreview(filePath, this.fsProvider);
-      } catch (error) {
-        lastError = error;
-        if (attempt < maxAttempts && this.isTransientFsError(error)) {
-          await this.sleep(50 * attempt);
-          continue;
-        }
-        break;
-      }
-    }
-
-    if (lastError) {
-      logger.debug(`Failed to extract light preview for ${filePath}:`, lastError);
-    }
-    return null;
-  }
-
   private getErrorCode(error: unknown): string {
     if (typeof error === 'object' && error !== null && 'code' in error) {
       const code = (error as { code?: unknown }).code;

test/main/services/discovery/ProjectScanner.lightMetadata.test.ts

@@ -0,0 +1,72 @@
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+import { afterEach, describe, expect, it } from 'vitest';
+
+import { ProjectScanner } from '../../../../src/main/services/discovery/ProjectScanner';
+
+describe('ProjectScanner light metadata', () => {
+  const tempDirs: string[] = [];
+
+  afterEach(() => {
+    for (const dir of tempDirs) {
+      try {
+        fs.rmSync(dir, { recursive: true, force: true, maxRetries: 5, retryDelay: 200 });
+      } catch {
+        // Ignore cleanup failures
+      }
+    }
+    tempDirs.length = 0;
+  });
+
+  it('reuses analyzed metadata so light sessions expose the real message count', async () => {
+    const projectsDir = fs.mkdtempSync(path.join(os.tmpdir(), 'scanner-light-'));
+    tempDirs.push(projectsDir);
+
+    const encodedName = '-Users-test-myproject';
+    const projectDir = path.join(projectsDir, encodedName);
+    fs.mkdirSync(projectDir);
+
+    const filePath = path.join(projectDir, 'session.jsonl');
+    fs.writeFileSync(
+      filePath,
+      [
+        JSON.stringify({
+          type: 'user',
+          uuid: 'u1',
+          cwd: '/Users/test/myproject',
+          timestamp: '2026-01-01T00:00:00.000Z',
+          message: { role: 'user', content: 'hello world' },
+        }),
+        JSON.stringify({
+          type: 'assistant',
+          uuid: 'a1',
+          timestamp: '2026-01-01T00:00:01.000Z',
+          message: { role: 'assistant', content: 'hi there' },
+        }),
+      ].join('\n') + '\n',
+      'utf8'
+    );
+
+    const scanner = new ProjectScanner(projectsDir);
+    const session = await (
+      scanner as unknown as {
+        buildLightSessionMetadata: (
+          projectId: string,
+          sessionId: string,
+          filePath: string,
+          projectPath: string
+        ) => Promise<{ messageCount: number; firstMessage?: string; metadataLevel: string }>;
+      }
+    ).buildLightSessionMetadata(
+      encodedName,
+      'session',
+      filePath,
+      '/Users/test/myproject'
+    );
+
+    expect(session.metadataLevel).toBe('light');
+    expect(session.firstMessage).toBe('hello world');
+    expect(session.messageCount).toBe(2);
+  });
+});