chore: import upstream snapshot with attribution

tests/scan-progress.test.ts

@@ -0,0 +1,66 @@
+import { describe, it, expect, vi, afterEach } from 'vitest'
+import { createScanProgress, setInteractiveScanUI } from '../src/parser.js'
+
+// The scan-progress line must be silent while an interactive Ink UI (dashboard,
+// compare) is live, because it renders to the same terminal. The end-to-end
+// proof (cold dashboard WITH a plan stays silent; cold overview shows progress)
+// is documented in the PR and was run under a PTY.
+describe('createScanProgress gate', () => {
+  const origTTY = process.stderr.isTTY
+
+  afterEach(() => {
+    setInteractiveScanUI(false)
+    Object.defineProperty(process.stderr, 'isTTY', { value: origTTY, configurable: true })
+    vi.restoreAllMocks()
+  })
+
+  function forceTTY(v: boolean) {
+    Object.defineProperty(process.stderr, 'isTTY', { value: v, configurable: true })
+  }
+
+  it('writes progress for a plain CLI command in a TTY over the threshold', async () => {
+    forceTTY(true)
+    const w = vi.spyOn(process.stderr, 'write').mockReturnValue(true)
+    const p = createScanProgress('scanning', 100)
+    await p.tick(100) // final tick bypasses the 100ms throttle
+    expect(w).toHaveBeenCalled()
+    expect(String(w.mock.calls[0]![0])).toContain('scanning 100/100')
+  })
+
+  it('goes silent once an interactive Ink UI is active, even in a TTY', async () => {
+    forceTTY(true)
+    setInteractiveScanUI() // dashboard/compare call this right before render()
+    const w = vi.spyOn(process.stderr, 'write').mockReturnValue(true)
+    const p = createScanProgress('scanning', 100)
+    for (let i = 1; i <= 100; i++) await p.tick(i)
+    p.finish()
+    expect(w).not.toHaveBeenCalled()
+  })
+
+  it('finish() clears the line when progress was shown', async () => {
+    forceTTY(true)
+    const w = vi.spyOn(process.stderr, 'write').mockReturnValue(true)
+    const p = createScanProgress('scanning', 100)
+    await p.tick(100)
+    w.mockClear()
+    p.finish()
+    expect(String(w.mock.calls[0]![0])).toBe('\r\x1b[K')
+  })
+
+  it('writes nothing when stderr is not a TTY (piped/captured output)', async () => {
+    forceTTY(false)
+    const w = vi.spyOn(process.stderr, 'write').mockReturnValue(true)
+    const p = createScanProgress('scanning', 100)
+    await p.tick(100)
+    p.finish()
+    expect(w).not.toHaveBeenCalled()
+  })
+
+  it('stays silent below the small-tree threshold', async () => {
+    forceTTY(true)
+    const w = vi.spyOn(process.stderr, 'write').mockReturnValue(true)
+    const p = createScanProgress('scanning', 5)
+    await p.tick(5)
+    expect(w).not.toHaveBeenCalled()
+  })
+})