Function assertInteractionContract

src/testing/replContractHarness.ts:81–133

(
  label: string,
  frames: readonly T[],
  output: string,
  budget: InteractionBudget,
  readMetrics: (frame: T) => InteractionFrameMetrics,
)

}

export function assertInteractionContract<T>(
  label: string,
  frames: readonly T[],
  output: string,
  budget: InteractionBudget,
  readMetrics: (frame: T) => InteractionFrameMetrics,
): void {
  expect(frames.length, `${label} emitted no frames`).toBeGreaterThan(0)

  const metrics = frames.map(readMetrics)

  expect(
    metrics.every(frame => frame.flickers === 0),
    `${label} emitted flicker frames`,
  ).toBe(true)
  expect(output.includes('\u001b[2J'), `${label} emitted ED2 clear-screen`).toBe(
    false,
  )
  expect(output.includes('\u001b[3J'), `${label} emitted ED3 scrollback wipe`).toBe(
    false,
  )

  if (budget.maxFrames !== undefined && frames.length > budget.maxFrames) {
    throw new Error(
      `${label} exceeded the frame budget: ${frames.length} > ${budget.maxFrames}`,
    )
  }

  const maxBytes = Math.max(...metrics.map(frame => frame.bytes), 0)
  if (maxBytes > budget.maxBytes) {
    throw new Error(
      `${label} exceeded the repaint byte budget: ${maxBytes} > ${budget.maxBytes}`,
    )
  }

  if (budget.maxMeasured !== undefined) {
    const maxMeasured = Math.max(...metrics.map(frame => frame.yogaMeasured), 0)
    if (maxMeasured > budget.maxMeasured) {
      throw new Error(
        `${label} exceeded the Yoga measure budget: ${maxMeasured} > ${budget.maxMeasured}`,
      )
    }
  }

  if (budget.maxVisited !== undefined) {
    const maxVisited = Math.max(...metrics.map(frame => frame.yogaVisited), 0)
    if (maxVisited > budget.maxVisited) {
      throw new Error(
        `${label} exceeded the Yoga visit budget: ${maxVisited} > ${budget.maxVisited}`,
      )
    }
  }
}

export function readJsonLines<T>(path: string): T[] {
  if (!existsSync(path)) {