initial ai assistance

test/ai.test.tsx

@@ -0,0 +1,58 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { cleanup, fireEvent, render, screen, waitFor } from '@testing-library/react'
+import { cleanReply, rewriteMessages } from '../src/ai/rewrite'
+
+const generate = vi.fn()
+vi.mock('../src/ai/engine', () => ({
+  aiSupported: () => true,
+  getEngine: async () => ({ generate }),
+}))
+const { RewriteButton } = await import('../src/ai/RewriteButton')
+
+afterEach(() => {
+  cleanup()
+  generate.mockReset()
+})
+
+describe('rewrite prompts', () => {
+  it('carries the task, text, format and length limit', () => {
+    const m = rewriteMessages('shorten', 'Hello world', { 'x-editor': 'markdown', maxLength: 50 }, 'Intro')
+    expect(m[0].content).toContain('Markdown')
+    expect(m[0].content).toContain('50 characters')
+    expect(m[1].content).toContain('Field: Intro')
+    expect(m[1].content).toContain('Hello world')
+  })
+  it('strips fences/quotes and enforces maxLength', () => {
+    expect(cleanReply('```\nHi there\n```', {})).toBe('Hi there')
+    expect(cleanReply('"Hi there"', {})).toBe('Hi there')
+    expect(cleanReply('abcdefghij', { maxLength: 4 })).toBe('abcd')
+  })
+})
+
+describe('RewriteButton', () => {
+  it('only writes after Accept', async () => {
+    generate.mockResolvedValue('Better text')
+    const onAccept = vi.fn()
+    render(<RewriteButton schema={{}} value="Bad txt" onAccept={onAccept} />)
+    fireEvent.change(screen.getByLabelText('Rewrite with AI'), { target: { value: 'fix' } })
+    await screen.findByLabelText('AI suggestion')
+    expect(onAccept).not.toHaveBeenCalled()
+    fireEvent.click(screen.getByText('Accept'))
+    expect(onAccept).toHaveBeenCalledWith('Better text')
+  })
+  it('Reject leaves the value alone', async () => {
+    generate.mockResolvedValue('Other')
+    const onAccept = vi.fn()
+    render(<RewriteButton schema={{}} value="x" onAccept={onAccept} />)
+    fireEvent.change(screen.getByLabelText('Rewrite with AI'), { target: { value: 'improve' } })
+    fireEvent.click(await screen.findByText('Reject'))
+    expect(onAccept).not.toHaveBeenCalled()
+    await waitFor(() => screen.getByLabelText('Rewrite with AI'))
+  })
+  it('surfaces engine errors', async () => {
+    generate.mockRejectedValue(new Error('boom'))
+    render(<RewriteButton schema={{}} value="x" onAccept={() => {}} />)
+    fireEvent.change(screen.getByLabelText('Rewrite with AI'), { target: { value: 'improve' } })
+    expect((await screen.findByRole('alert')).textContent).toBe('boom')
+  })
+})