fix: address Select forwarding and MCP readiness review

packages/mcp/src/index.ts

@@ -98,6 +98,11 @@ const handle = await startServer({
   appAttachTimeoutMs
 })
 
+const readyMarker = process.env.OPENPENCIL_MCP_READY_MARKER
+if (readyMarker && /^open-pencil-ready:[a-f0-9-]{36}$/.test(readyMarker)) {
+  process.stderr.write(`${readyMarker}\n`)
+}
+
 process.stderr.write(`OpenPencil MCP server\n`)
 if (handle.socketPath) process.stderr.write(`  Socket: ${handle.socketPath}\n`)
 if (handle.httpPort) process.stderr.write(`  HTTP:   http://127.0.0.1:${handle.httpPort}\n`)

src/app/automation/bridge/child-ready.ts

@@ -0,0 +1,34 @@
+import type { ChildProcess } from 'node:child_process'
+import { createInterface } from 'node:readline'
+import type { Readable } from 'node:stream'
+
+/** Readiness is acknowledged over the owned child pipe, never by a public HTTP listener. */
+export function waitForChildReady(
+  child: ChildProcess & { stderr: Readable },
+  marker: string,
+  timeoutMs = 10_000
+): Promise<void> {
+  return new Promise((resolve, reject) => {
+    const lines = createInterface({ input: child.stderr })
+    const timer = setTimeout(() => finish(new Error('MCP child readiness timed out')), timeoutMs)
+    function finish(error?: Error) {
+      clearTimeout(timer)
+      lines.close()
+      child.off('exit', onExit)
+      child.off('error', onError)
+      if (error) reject(error)
+      else resolve()
+    }
+    function onExit() {
+      finish(new Error('MCP child exited before readiness acknowledgement'))
+    }
+    function onError(error: Error) {
+      finish(error)
+    }
+    child.once('exit', onExit)
+    child.once('error', onError)
+    lines.on('line', (line) => {
+      if (line === marker) finish()
+    })
+  })
+}

src/app/automation/bridge/vite-plugin.ts

@@ -1,5 +1,5 @@
 import { spawn } from 'node:child_process'
-import { createHash } from 'node:crypto'
+import { createHash, randomUUID } from 'node:crypto'
 import { mkdir } from 'node:fs/promises'
 import type { IncomingMessage } from 'node:http'
 import { tmpdir } from 'node:os'
@@ -15,6 +15,7 @@ import {
   parseDevMCPConfiguration,
   type DevMCPConfiguration
 } from '../mcp/dev-control'
+import { waitForChildReady } from './child-ready'
 
 interface AutomationEnvironmentOptions {
   authToken: string | null
@@ -103,28 +104,22 @@ export async function readDevMCPConfiguration(request: IncomingMessage): Promise
 export async function waitForAutomationHealth(
   browserURL: string,
   fetcher: typeof fetch = fetch,
-  options: { authToken?: string | null; assertRunning?: () => void } = {}
+  options: { assertRunning?: () => void } = {}
 ): Promise<void> {
   const healthURL = `${browserURL.replace(/^ws/, 'http')}/health`
   for (let attempt = 0; attempt < CHILD_HEALTH_ATTEMPTS; attempt++) {
     options.assertRunning?.()
+    let healthy = false
     try {
-      const response = await fetcher(healthURL, {
-        signal: AbortSignal.timeout(2000),
-        headers: options.authToken ? { Authorization: `Bearer ${options.authToken}` } : undefined
-      })
-      if (response.ok) {
-        const authenticated =
-          !options.authToken ||
-          Array.isArray(((await response.json()) as { tools?: unknown }).tools)
-        options.assertRunning?.()
-        if (authenticated) return
-      }
+      const response = await fetcher(healthURL, { signal: AbortSignal.timeout(2000) })
+      healthy = response.ok
     } catch (error) {
       if (attempt === CHILD_HEALTH_ATTEMPTS - 1) {
         console.warn(`[MCP] Health check failed at ${healthURL}`, error)
       }
     }
+    options.assertRunning?.()
+    if (healthy) return
     await new Promise<void>((resolve) => {
       setTimeout(resolve, CHILD_HEALTH_DELAY_MS)
     })
@@ -205,18 +200,23 @@ export function automationPlugin(
     const spawnArgs = options.portlessServiceName
       ? ['run', '--name', options.portlessServiceName, ...command]
       : command.slice(1)
+    const readyMarker = `open-pencil-ready:${randomUUID()}`
     const spawned = spawn(spawnCommand, spawnArgs, {
       stdio: ['ignore', 'inherit', 'pipe'],
-      env: createAutomationEnvironment({
-        authToken,
-        baseEnv: process.env,
-        configuration,
-        corsOrigin: options.corsOrigin,
-        discoveryPath,
-        httpPort: options.httpPort,
-        socketPath
-      })
+      env: {
+        ...createAutomationEnvironment({
+          authToken,
+          baseEnv: process.env,
+          configuration,
+          corsOrigin: options.corsOrigin,
+          discoveryPath,
+          httpPort: options.httpPort,
+          socketPath
+        }),
+        OPENPENCIL_MCP_READY_MARKER: readyMarker
+      }
     })
+    const ready = waitForChildReady(spawned, readyMarker)
     child = spawned
 
     spawned.on('error', (err) => {
@@ -242,8 +242,13 @@ export function automationPlugin(
       if (child === spawned) child = null
     })
 
+    try {
+      await ready
+    } catch (error) {
+      spawned.kill()
+      throw error
+    }
     await waitForAutomationHealth(options.browserURL, fetch, {
-      authToken: configuration.authenticationEnabled ? authToken : null,
       assertRunning() {
         if (child !== spawned || spawned.exitCode !== null || spawned.signalCode !== null) {
           throw new Error('MCP child exited before becoming ready')

src/components/ui/select/AppSelect.vue

@@ -34,7 +34,7 @@ const styles = tv(theme)()
 
 <template>
   <SelectRoot v-model="modelValue">
-    <SelectTrigger v-if="$slots.trigger" as-child>
+    <SelectTrigger v-if="$slots.trigger" as-child v-bind="$attrs" :aria-label="label">
       <slot name="trigger" />
     </SelectTrigger>
     <SelectTrigger

tests/e2e/properties/select-trigger.spec.ts

@@ -16,6 +16,7 @@ for (const custom of [false, true]) {
       const { default: AppSelect } = await import(selectPath)
       const { default: IconButton } = await import(buttonPath)
       const value = ref('first')
+      const disabled = ref(false)
       const host = document.createElement('div')
       host.dataset.slot = 'select-contract-fixture'
       document.body.append(host)
@@ -24,6 +25,8 @@ for (const custom of [false, true]) {
           AppSelect,
           {
             modelValue: value.value,
+            disabled: disabled.value,
+            'data-command': 'choose-test-style',
             'onUpdate:modelValue': (next: string) => {
               value.value = next
             },
@@ -39,6 +42,9 @@ for (const custom of [false, true]) {
       app.mount(host)
       return {
         value: () => value.value,
+        disable: () => {
+          disabled.value = true
+        },
         dispose() {
           app.unmount()
           host.remove()
@@ -61,6 +67,11 @@ for (const custom of [false, true]) {
       await page.keyboard.press('Escape')
       await expect(trigger).toBeFocused()
       if (!custom) await expect(trigger).toHaveText('Second')
+      await expect(trigger).toHaveAttribute('data-command', 'choose-test-style')
+      await fixture.evaluate((state) => state.disable())
+      await expect(trigger).toBeDisabled()
+      await trigger.dispatchEvent('click')
+      await expect(page.getByRole('option')).toHaveCount(0)
     } finally {
       await fixture.evaluate((state) => state.dispose())
       await fixture.dispose()

tests/engine/app/automation/child-ready.test.ts

@@ -0,0 +1,20 @@
+import { expect, test } from 'bun:test'
+import { spawn } from 'node:child_process'
+
+import { waitForChildReady } from '@/app/automation/bridge/child-ready'
+
+test('accepts a readiness marker split across child output chunks', async () => {
+  const child = spawn(
+    process.execPath,
+    ['-e', 'process.stderr.write("ready:"); setTimeout(() => process.stderr.write("test\\n"), 10)'],
+    { stdio: ['ignore', 'ignore', 'pipe'] }
+  )
+  await waitForChildReady(child, 'ready:test')
+})
+
+test('rejects child exit without readiness even if other output looks healthy', async () => {
+  const child = spawn(process.execPath, ['-e', 'process.stderr.write("HTTP healthy\\n")'], {
+    stdio: ['ignore', 'ignore', 'pipe']
+  })
+  await expect(waitForChildReady(child, 'ready:test')).rejects.toThrow('exited before readiness')
+})

tests/engine/app/automation/mcp-vite-plugin.test.ts

@@ -100,18 +100,29 @@ describe('MCP Vite development server', () => {
     ])
   })
 
-  test('does not accept an unrelated healthy endpoint during authenticated startup', async () => {
-    let requests = 0
-    await waitForAutomationHealth(
-      'ws://localhost:7682',
-      async (_input, init) => {
-        expect(new Headers(init?.headers).get('authorization')).toBe('Bearer test-owned-token')
-        requests++
-        return Response.json(requests === 1 ? { status: 'ok' } : { status: 'no_app', tools: [] })
-      },
-      { authToken: 'test-owned-token' }
-    )
-    expect(requests).toBe(2)
+  test('health probes do not send credentials', async () => {
+    await waitForAutomationHealth('ws://localhost:7682', async (_input, init) => {
+      expect(new Headers(init?.headers).has('authorization')).toBe(false)
+      return new Response(null)
+    })
+  })
+
+  test('propagates child exit while the request is in flight', async () => {
+    let running = true
+    await expect(
+      waitForAutomationHealth(
+        'ws://localhost:7682',
+        async () => {
+          running = false
+          return new Response(null)
+        },
+        {
+          assertRunning() {
+            if (!running) throw new Error('child exited in flight')
+          }
+        }
+      )
+    ).rejects.toThrow('child exited in flight')
   })
 
   test('rejects a failed child before probing another endpoint', async () => {