async function createStreamVisualizer(asyncIterable, options) { const { maxPoints, alpha, width, height, yDomain } = options; const data = []; let ema; for await (const point of asyncIterable) { if (ema === undefined) { ema = point.value; } else { ema = alpha * point.value + (1 - alpha) * ema; } data.push({ timestamp: point.timestamp, value: point.value, ema }); if (data.length > maxPoints) { data.shift(); } } if (data.length === 0) { return { data, path: '' }; } const d3 = await import('https://cdn.jsdelivr.net/npm/d3@7/+esm'); const xDomain = [data[0].timestamp, data[data.length - 1].timestamp]; const xScale = d3.scaleLinear().domain(xDomain).range([0, width]); const yScale = d3.scaleLinear().domain(yDomain).range([height, 0]); const lineGenerator = d3.line() .x(d => xScale(d.timestamp)) .y(d => yScale(d.ema)); return { data, path: lineGenerator(data) }; } export default createStreamVisualizer; // Generation time: 21.308s // Result: PASS