| import { expect, test } from "bun:test" |
| import { compressCachedRepaintTrace, layoutShiftSample } from "../timeline/session-tab-repaint-probe" |
|
|
| test("compresses repeated repaint states without losing frame samples", () => { |
| const state = { |
| root: 1, |
| scrollTop: 10, |
| scrollHeight: 20, |
| bottomErrorPx: 0, |
| last: true, |
| rows: [{ key: "row", node: 2, top: 0, bottom: 10 }], |
| mounted: 1, |
| center: "content", |
| } |
| const trace = { |
| timeOriginEpochMs: 1_000, |
| startedAtPerformanceMs: 100, |
| samples: [ |
| { observedAtMs: 16, ...state, destination: ["target"], source: [] }, |
| { observedAtMs: 32, ...state, destination: ["target"], source: [] }, |
| { observedAtMs: 48, ...state, scrollTop: 11, destination: ["target"], source: [] }, |
| ], |
| mutations: [{ observedAtMs: 20, changed: [{ type: "add", node: 2 }] }], |
| shifts: [{ occurredAtMs: 24, value: 0.1 }], |
| windowMs: 1_000, |
| running: false, |
| stop() {}, |
| } |
| const compressed = compressCachedRepaintTrace(trace) |
| const samples = compressed.samples.flatMap((group) => |
| group.observedAtMs.map((observedAtMs) => ({ observedAtMs, ...group.state })), |
| ) |
|
|
| expect(samples).toEqual(trace.samples) |
| expect(compressed.mutations).toEqual(trace.mutations) |
| expect(compressed.shifts).toEqual(trace.shifts) |
| }) |
|
|
| test("records layout shifts at occurrence time within the probe window", () => { |
| expect(layoutShiftSample({ startTime: 99, value: 0.1 }, 100)).toBeUndefined() |
| expect(layoutShiftSample({ startTime: 124, value: 0.2 }, 100)).toEqual({ occurredAtMs: 24, value: 0.2 }) |
| }) |
|
|
