packages/mosaic/src/commands/fleet.spec.ts

@@ -493,7 +493,13 @@ describe('fleet command construction', () => {
     ]);
   });
 
-  it('runs fleet status through injected runner without touching tmux in tests', async () => {
+  it('runs legacy fleet status through injected runner without touching tmux in tests', async () => {
+    const home = await tempDir();
+    await mkdir(join(home, 'fleet'), { recursive: true });
+    await writeFile(
+      join(home, 'fleet', 'roster.yaml'),
+      'version: 1\ntransport: tmux\nagents: []\n',
+    );
     const calls: string[][] = [];
     const runner: CommandRunner = async (command, args) => {
       calls.push([command, ...args]);
@@ -501,11 +507,14 @@ describe('fleet command construction', () => {
     };
     const program = new Command();
     program.exitOverride();
-    registerFleetCommand(program, { runner });
+    registerFleetCommand(program, { runner, mosaicHome: home });
 
-    await program.parseAsync(['node', 'mosaic', 'fleet', 'status']);
-
-    expect(calls).toEqual([['systemctl', '--user', 'status', 'mosaic-tmux-holder.service']]);
+    try {
+      await program.parseAsync(['node', 'mosaic', 'fleet', 'status']);
+      expect(calls).toEqual([['systemctl', '--user', 'status', 'mosaic-tmux-holder.service']]);
+    } finally {
+      await rm(home, { recursive: true, force: true });
+    }
   });
 
   it('verifies liveness with tmux has-session and does not trust systemd active exited', async () => {
@@ -621,13 +630,19 @@ describe('fleet command construction', () => {
     ).rejects.toThrow('Unsupported fleet profile');
   });
 
-  it('sets process exitCode when status runner fails', async () => {
+  it('sets process exitCode when legacy status runner fails', async () => {
+    const home = await tempDir();
+    await mkdir(join(home, 'fleet'), { recursive: true });
+    await writeFile(
+      join(home, 'fleet', 'roster.yaml'),
+      'version: 1\ntransport: tmux\nagents: []\n',
+    );
     const originalExitCode = process.exitCode;
     const stderrSpy = vi.spyOn(process.stderr, 'write').mockImplementation(() => true);
     const runner: CommandRunner = async () => ({ stdout: '', stderr: 'missing\n', exitCode: 3 });
     const program = new Command();
     program.exitOverride();
-    registerFleetCommand(program, { runner });
+    registerFleetCommand(program, { runner, mosaicHome: home });
 
     try {
       await program.parseAsync(['node', 'mosaic', 'fleet', 'status']);
@@ -635,6 +650,7 @@ describe('fleet command construction', () => {
     } finally {
       process.exitCode = originalExitCode;
       stderrSpy.mockRestore();
+      await rm(home, { recursive: true, force: true });
     }
   });
 

packages/mosaic/src/fleet/fleet-reconciler.spec.ts

@@ -134,11 +134,10 @@ describe('fleet roster-owned reconciler', (): void => {
     });
     await rm(lockPath);
 
-    await chmod(fleet, 0o500);
-    await expect(acquirePrivateReconcileLock(home)()).rejects.toMatchObject({
-      code: 'lock-io-failed',
-    });
-    await chmod(fleet, 0o700);
+    const ioFailure = Object.assign(new Error('injected I/O failure'), { code: 'EIO' });
+    await expect(
+      acquirePrivateReconcileLock(home, async () => Promise.reject(ioFailure))(),
+    ).rejects.toMatchObject({ code: 'lock-io-failed' });
   });
 
   it('does not unlink a replacement lock and normally releases its own lock', async (): Promise<void> => {

packages/mosaic/src/fleet/fleet-reconciler.ts

@@ -609,6 +609,7 @@ function mosaicHomeFor(deps: FleetReconcileDeps): string {
 /** Acquires a private lock only after proving the canonical managed path. */
 export function acquirePrivateReconcileLock(
   mosaicHome: string,
+  openLock: typeof open = open,
 ): () => Promise<() => Promise<void>> {
   const fleetDir = join(mosaicHome, 'fleet');
   const lockPath = join(fleetDir, 'roster.yaml.reconcile.lock');
@@ -619,7 +620,7 @@ export function acquirePrivateReconcileLock(
 
     let handle: FileHandle;
     try {
-      handle = await open(lockPath, 'wx', 0o600);
+      handle = await openLock(lockPath, 'wx', 0o600);
     } catch (error: unknown) {
       if (isCode(error, 'EEXIST')) {
         await assertSafeLockLeafIfPresent(lockPath);