fix: use parent project name for worktree observation writes (#1820)

* fix: use parent project name for worktree observation writes (#1819)

Observations and sessions from git worktrees were stored under
basename(cwd) instead of the parent repo name because write paths
called getProjectName() (not worktree-aware) instead of
getProjectContext() (worktree-aware). This is the same bug as
#1081, #1317, and #1500 — it regressed because the two functions
coexist and new code reached for the simpler one.

Fix: getProjectContext() now returns parentProjectName as primary
when in a worktree, and all four write-path call sites now use
getProjectContext().primary instead of getProjectName().

Includes regression test that creates a real worktree directory
structure and asserts primary === parentProjectName.

* fix: address review nitpicks — allProjects fallback, JSDoc, write-path test

- ContextBuilder: default projects to context.allProjects for legacy
  worktree-labeled record compatibility
- ProjectContext: clarify JSDoc that primary is canonical (parent repo
  in worktrees)
- Tests: add write-path regression test mirroring session-init/SessionRoutes
  pattern; refactor worktree fixture into beforeAll/afterAll

* refactor(project-name): rename local to cwdProjectName and dedupe allProjects

Addresses final CodeRabbit nitpick: disambiguates the local variable
from the returned `primary` field, and dedupes allProjects via Set
in case parent and cwd resolve to the same name.

---------

Co-authored-by: Ethan Hurst <ethan.hurst@outlook.com.au>

src/cli/handlers/session-init.ts

@@ -6,7 +6,7 @@
 
 import type { EventHandler, NormalizedHookInput, HookResult } from '../types.js';
 import { ensureWorkerRunning, workerHttpRequest } from '../../shared/worker-utils.js';
-import { getProjectName } from '../../utils/project-name.js';
+import { getProjectContext } from '../../utils/project-name.js';
 import { logger } from '../../utils/logger.js';
 import { HOOK_EXIT_CODES } from '../../shared/hook-constants.js';
 import { isProjectExcluded } from '../../utils/project-filter.js';
@@ -42,7 +42,7 @@ export const sessionInitHandler: EventHandler = {
     // Use placeholder so sessions still get created and tracked for memory
     const prompt = (!rawPrompt || !rawPrompt.trim()) ? '[media prompt]' : rawPrompt;
 
-    const project = getProjectName(cwd);
+    const project = getProjectContext(cwd).primary;
     const platformSource = normalizePlatformSource(input.platform);
 
     logger.debug('HOOK', 'session-init: Calling /api/sessions/init', { contentSessionId: sessionId, project });

src/services/context/ContextBuilder.ts

@@ -10,7 +10,7 @@ import { homedir } from 'os';
 import { unlinkSync } from 'fs';
 import { SessionStore } from '../sqlite/SessionStore.js';
 import { logger } from '../../utils/logger.js';
-import { getProjectName } from '../../utils/project-name.js';
+import { getProjectContext } from '../../utils/project-name.js';
 
 import type { ContextInput, ContextConfig, Observation, SessionSummary } from './types.js';
 import { loadContextConfig } from './ContextConfigLoader.js';
@@ -129,11 +129,12 @@ export async function generateContext(
 ): Promise<string> {
   const config = loadContextConfig();
   const cwd = input?.cwd ?? process.cwd();
-  const project = getProjectName(cwd);
+  const context = getProjectContext(cwd);
+  const project = context.primary;
   const platformSource = input?.platform_source;
 
-  // Use provided projects array (for worktree support) or fall back to single project
-  const projects = input?.projects || [project];
+  // Use provided projects array (for worktree support) or fall back to all known projects
+  const projects = input?.projects ?? context.allProjects;
 
   // Full mode: fetch all observations but keep normal rendering (level 1 summaries)
   if (input?.full) {

src/services/transcripts/processor.ts

@@ -4,7 +4,7 @@ import { fileEditHandler } from '../../cli/handlers/file-edit.js';
 import { sessionCompleteHandler } from '../../cli/handlers/session-complete.js';
 import { ensureWorkerRunning, workerHttpRequest } from '../../shared/worker-utils.js';
 import { logger } from '../../utils/logger.js';
-import { getProjectContext, getProjectName } from '../../utils/project-name.js';
+import { getProjectContext } from '../../utils/project-name.js';
 import { writeAgentsMd } from '../../utils/agents-md-utils.js';
 import { resolveFieldSpec, resolveFields, matchesRule } from './field-utils.js';
 import { expandHomePath } from './config.js';
@@ -104,7 +104,7 @@ export class TranscriptEventProcessor {
     const resolved = resolveFieldSpec(fieldSpec, entry, ctx);
     if (typeof resolved === 'string' && resolved.trim()) return resolved;
     if (watch.project) return watch.project;
-    if (session.cwd) return getProjectName(session.cwd);
+    if (session.cwd) return getProjectContext(session.cwd).primary;
     return session.project;
   }
 

src/services/worker/http/routes/SessionRoutes.ts

@@ -22,7 +22,7 @@ import { PrivacyCheckValidator } from '../../validation/PrivacyCheckValidator.js
 import { SettingsDefaultsManager } from '../../../../shared/SettingsDefaultsManager.js';
 import { USER_SETTINGS_PATH } from '../../../../shared/paths.js';
 import { getProcessBySession, ensureProcessExit } from '../../ProcessRegistry.js';
-import { getProjectName } from '../../../../utils/project-name.js';
+import { getProjectContext } from '../../../../utils/project-name.js';
 import { normalizePlatformSource } from '../../../../shared/platform-source.js';
 
 export class SessionRoutes extends BaseRouteHandler {
@@ -507,7 +507,7 @@ export class SessionRoutes extends BaseRouteHandler {
   private handleObservationsByClaudeId = this.wrapHandler((req: Request, res: Response): void => {
     const { contentSessionId, tool_name, tool_input, tool_response, cwd } = req.body;
     const platformSource = normalizePlatformSource(req.body.platformSource);
-    const project = typeof cwd === 'string' && cwd.trim() ? getProjectName(cwd) : '';
+    const project = typeof cwd === 'string' && cwd.trim() ? getProjectContext(cwd).primary : '';
 
     if (!contentSessionId) {
       return this.badRequest(res, 'Missing contentSessionId');

src/utils/project-name.ts

@@ -58,13 +58,13 @@ export function getProjectName(cwd: string | null | undefined): string {
  * Project context with worktree awareness
  */
 export interface ProjectContext {
-  /** The current project name (worktree or main repo) */
+  /** Canonical project name for writes/queries (parent repo in worktrees) */
   primary: string;
   /** Parent project name if in a worktree, null otherwise */
   parent: string | null;
   /** True if currently in a worktree */
   isWorktree: boolean;
-  /** All projects to query: [primary] for main repo, [parent, primary] for worktree */
+  /** All projects to query: [primary] for main repo, [parentRepo, worktreeName] for worktree */
   allProjects: string[];
 }
 
@@ -78,24 +78,26 @@ export interface ProjectContext {
  * @returns ProjectContext with worktree info
  */
 export function getProjectContext(cwd: string | null | undefined): ProjectContext {
-  const primary = getProjectName(cwd);
+  const cwdProjectName = getProjectName(cwd);
 
   if (!cwd) {
-    return { primary, parent: null, isWorktree: false, allProjects: [primary] };
+    return { primary: cwdProjectName, parent: null, isWorktree: false, allProjects: [cwdProjectName] };
   }
 
   const expandedCwd = expandTilde(cwd);
   const worktreeInfo = detectWorktree(expandedCwd);
 
   if (worktreeInfo.isWorktree && worktreeInfo.parentProjectName) {
-    // In a worktree: include parent first for chronological ordering
+    // In a worktree: use parent project name as primary so observations
+    // are stored under the same project as the main repo (#1081, #1500, #1819)
+    const allProjects = Array.from(new Set([worktreeInfo.parentProjectName, cwdProjectName]));
     return {
-      primary,
+      primary: worktreeInfo.parentProjectName,
       parent: worktreeInfo.parentProjectName,
       isWorktree: true,
-      allProjects: [worktreeInfo.parentProjectName, primary]
+      allProjects
     };
   }
 
-  return { primary, parent: null, isWorktree: false, allProjects: [primary] };
+  return { primary: cwdProjectName, parent: null, isWorktree: false, allProjects: [cwdProjectName] };
 }

tests/utils/project-name.test.ts

@@ -5,7 +5,7 @@
  * Source: src/utils/project-name.ts
  */
 
-import { describe, it, expect } from 'bun:test';
+import { describe, it, expect, beforeAll, afterAll } from 'bun:test';
 import { homedir } from 'os';
 import { getProjectName, getProjectContext } from '../../src/utils/project-name.js';
 
@@ -96,4 +96,51 @@ describe('getProjectContext', () => {
     expect(ctx.primary).toBe('unknown-project');
     expect(ctx.parent).toBeNull();
   });
+
+  describe('worktree regression (#1081, #1500, #1819)', () => {
+    let tmp: string;
+    let mainRepo: string;
+    let worktreeCheckout: string;
+
+    beforeAll(async () => {
+      const { mkdtempSync, mkdirSync, writeFileSync } = await import('fs');
+      const { join } = await import('path');
+      const { tmpdir } = await import('os');
+
+      tmp = mkdtempSync(join(tmpdir(), 'cm-wt-'));
+      mainRepo = join(tmp, 'main-repo');
+      const worktreeGitDir = join(mainRepo, '.git', 'worktrees', 'my-worktree');
+      worktreeCheckout = join(tmp, 'my-worktree');
+
+      mkdirSync(worktreeGitDir, { recursive: true });
+      mkdirSync(worktreeCheckout, { recursive: true });
+      writeFileSync(
+        join(worktreeCheckout, '.git'),
+        `gitdir: ${worktreeGitDir}\n`
+      );
+    });
+
+    afterAll(async () => {
+      const { rmSync } = await import('fs');
+      rmSync(tmp, { recursive: true, force: true });
+    });
+
+    it('uses parent project name as primary when in a worktree', () => {
+      const ctx = getProjectContext(worktreeCheckout);
+      expect(ctx.isWorktree).toBe(true);
+      expect(ctx.primary).toBe('main-repo');
+      expect(ctx.parent).toBe('main-repo');
+      expect(ctx.allProjects).toEqual(['main-repo', 'my-worktree']);
+    });
+
+    it('write-path call sites resolve to parent project in worktrees', () => {
+      // Mirrors the pattern used by session-init.ts and SessionRoutes.ts:
+      //   const project = getProjectContext(cwd).primary;
+      // This must resolve to the parent repo, not the worktree name,
+      // so observations are stored under the correct project.
+      const project = getProjectContext(worktreeCheckout).primary;
+      expect(project).toBe('main-repo');
+      expect(project).not.toBe('my-worktree');
+    });
+  });
 });