Bridge handler regression net: pre-read map, ack, degrades

Six mocked-boundary tests for the paths the live e2e exercised: @token
pre-reads into the embed map, @@/@- passthrough, missing-file and
cold-machine degrades on both directions, ack-only stdout replacement,
and no write on command failure.

Claude-Session: https://claude.ai/code/session_01CgaxNAaeD3taGdghbXn17w

Author: Sg312

apps/sim/lib/mothership/tools/handlers/sim-cli-bridge.test.ts

@@ -0,0 +1,102 @@
+/**
+ * @vitest-environment node
+ */
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const { mockRead, mockWrite, mockRunEmbeddedCli, mockMint } = vi.hoisted(() => ({
+  mockRead: vi.fn(),
+  mockWrite: vi.fn(),
+  mockRunEmbeddedCli: vi.fn(),
+  mockMint: vi.fn(),
+}))
+
+vi.mock('@/lib/execution/remote-sandbox/session-files', () => ({
+  readSessionSandboxFile: mockRead,
+  writeSessionSandboxFile: mockWrite,
+}))
+vi.mock('sim/embed', () => ({
+  runEmbeddedCli: mockRunEmbeddedCli,
+  createEmbeddedClient: vi.fn(),
+}))
+vi.mock('@/lib/mothership/chat/delegation', () => ({ mintDelegationToken: mockMint }))
+vi.mock('@/lib/core/utils/urls', () => ({ getInternalApiBaseUrl: () => 'http://internal' }))
+
+import { executeSimCli } from '@/lib/mothership/tools/handlers/sim-cli'
+
+const context = { workspaceId: 'ws-1', userId: 'u-1', chatId: 'chat-1' } as Parameters<
+  typeof executeSimCli
+>[1]
+
+describe('sim-cli machine file bridge', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockMint.mockResolvedValue('key')
+    mockRunEmbeddedCli.mockResolvedValue({ exitCode: 0, stdout: 'BIG OUTPUT', stderr: '' })
+  })
+
+  it('pre-reads @tokens from the machine into the embed file map', async () => {
+    mockRead.mockResolvedValue({ outcome: 'read', content: '{"text":"hi"}' })
+    await executeSimCli({ args: ['workflows', 'run', 'wf1', '--input', '@env.json'] }, context)
+    expect(mockRead).toHaveBeenCalledWith('mothership-chat:chat-1', 'env.json')
+    expect(mockRunEmbeddedCli).toHaveBeenCalledWith(
+      ['workflows', 'run', 'wf1', '--input', '@env.json'],
+      expect.anything(),
+      { fileArguments: { 'env.json': '{"text":"hi"}' } }
+    )
+  })
+
+  it('leaves @@ literals and @- alone, and omits missing files from the map', async () => {
+    mockRead.mockResolvedValue({ outcome: 'no-file', detail: 'nope' })
+    await executeSimCli({ args: ['x', '@@literal', '@missing.json'] }, context)
+    expect(mockRead).toHaveBeenCalledTimes(1)
+    expect(mockRunEmbeddedCli).toHaveBeenCalledWith(
+      ['x', '@@literal', '@missing.json'],
+      expect.anything(),
+      {
+        fileArguments: {},
+      }
+    )
+  })
+
+  it('cold machine on read degrades via the empty map (CLI core words the refusal)', async () => {
+    mockRead.mockResolvedValue({ outcome: 'no-session' })
+    await executeSimCli({ args: ['x', '@env.json'] }, context)
+    expect(mockRunEmbeddedCli).toHaveBeenCalledWith(['x', '@env.json'], expect.anything(), {
+      fileArguments: {},
+    })
+  })
+
+  it('outputFile lands stdout on the machine and returns only the ack', async () => {
+    mockWrite.mockResolvedValue({ outcome: 'written', path: '/home/user/trace.json' })
+    const result = await executeSimCli(
+      { args: ['logs', 'get', 'r1'], outputFile: 'trace.json' },
+      context
+    )
+    expect(mockWrite).toHaveBeenCalledWith('mothership-chat:chat-1', 'trace.json', 'BIG OUTPUT')
+    const output = result.output as { stdout: string }
+    expect(output.stdout).toContain('written to trace.json')
+    expect(output.stdout).toContain('10 chars')
+    expect(output.stdout).not.toContain('BIG OUTPUT')
+  })
+
+  it('outputFile on a cold machine returns output inline with boot guidance', async () => {
+    mockWrite.mockResolvedValue({ outcome: 'no-session' })
+    const result = await executeSimCli(
+      { args: ['logs', 'get', 'r1'], outputFile: 'trace.json' },
+      context
+    )
+    const output = result.output as { stdout: string }
+    expect(output.stdout).toContain('BIG OUTPUT')
+    expect(output.stdout).toContain('not booted')
+  })
+
+  it('outputFile is skipped on command failure so the error stays visible', async () => {
+    mockRunEmbeddedCli.mockResolvedValue({ exitCode: 1, stdout: '', stderr: 'boom' })
+    const result = await executeSimCli(
+      { args: ['logs', 'get', 'r1'], outputFile: 'trace.json' },
+      context
+    )
+    expect(mockWrite).not.toHaveBeenCalled()
+    expect(result.success).toBe(false)
+  })
+})