Hermes-agent

ui-tui/src/__tests__/wheelAccel.test.ts

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+import { describe, expect, it } from 'vitest'
+
+import { computeWheelStep, initWheelAccel } from '../lib/wheelAccel.js'
+
+describe('wheelAccel — native path', () => {
+  it('first click after init returns base', () => {
+    const s = initWheelAccel(false, 1)
+
+    expect(computeWheelStep(s, 1, 1000)).toBe(1)
+  })
+
+  it('same-direction fast events ramp mult (window-mode)', () => {
+    const s = initWheelAccel(false, 1)
+
+    computeWheelStep(s, 1, 1000)
+    computeWheelStep(s, 1, 1020)
+    computeWheelStep(s, 1, 1040)
+
+    // Key property: doesn't shrink below base.
+    expect(computeWheelStep(s, 1, 1060)).toBeGreaterThanOrEqual(1)
+  })
+
+  it('gap beyond window resets mult to base', () => {
+    const s = initWheelAccel(false, 1)
+
+    for (let t = 1000; t < 1100; t += 20) {
+      computeWheelStep(s, 1, t)
+    }
+
+    expect(computeWheelStep(s, 1, 2000)).toBe(1)
+  })
+
+  it('direction flip defers one event for bounce detection', () => {
+    const s = initWheelAccel(false, 1)
+
+    computeWheelStep(s, 1, 1000)
+
+    expect(computeWheelStep(s, -1, 1050)).toBe(0)
+  })
+
+  it('flip-back within bounce window engages wheelMode', () => {
+    const s = initWheelAccel(false, 1)
+
+    computeWheelStep(s, 1, 1000)
+    computeWheelStep(s, -1, 1050)
+    computeWheelStep(s, 1, 1100)
+
+    expect(s.wheelMode).toBe(true)
+  })
+
+  it('flip-back outside bounce window is a real reversal (no wheelMode)', () => {
+    const s = initWheelAccel(false, 1)
+
+    computeWheelStep(s, 1, 1000)
+    computeWheelStep(s, -1, 1050)
+    computeWheelStep(s, 1, 1400)
+
+    expect(s.wheelMode).toBe(false)
+  })
+
+  it('5 consecutive sub-5ms events disengage wheelMode (trackpad signature)', () => {
+    const s = initWheelAccel(false, 1)
+    s.wheelMode = true
+    s.dir = 1
+    s.time = 1000
+
+    for (let t = 1002; t <= 1010; t += 2) {
+      computeWheelStep(s, 1, t)
+    }
+
+    expect(s.wheelMode).toBe(false)
+  })
+
+  it('1.5s idle disengages wheelMode', () => {
+    const s = initWheelAccel(false, 1)
+    s.wheelMode = true
+    s.dir = 1
+    s.time = 1000
+
+    computeWheelStep(s, 1, 3000)
+
+    expect(s.wheelMode).toBe(false)
+  })
+})
+
+describe('wheelAccel — xterm.js path', () => {
+  it('first click returns 2 after long idle', () => {
+    const s = initWheelAccel(true, 1)
+
+    expect(computeWheelStep(s, 1, 1000)).toBeGreaterThanOrEqual(1)
+  })
+
+  it('sub-5ms burst returns 1 (same-direction, same-batch)', () => {
+    const s = initWheelAccel(true, 1)
+
+    computeWheelStep(s, 1, 1000)
+
+    expect(computeWheelStep(s, 1, 1002)).toBe(1)
+  })
+
+  it('slow steady scroll stays in precision range', () => {
+    const s = initWheelAccel(true, 1)
+
+    for (let t = 1000; t < 2000; t += 33) {
+      const r = computeWheelStep(s, 1, t)
+
+      expect(r).toBeGreaterThanOrEqual(1)
+      expect(r).toBeLessThanOrEqual(6)
+    }
+  })
+
+  it('direction reversal resets mult', () => {
+    const s = initWheelAccel(true, 1)
+
+    for (let t = 1000; t < 1100; t += 20) {
+      computeWheelStep(s, 1, t)
+    }
+
+    const beforeFlip = s.mult
+
+    computeWheelStep(s, -1, 1200)
+
+    expect(s.mult).toBeLessThanOrEqual(beforeFlip)
+    expect(s.mult).toBe(2)
+  })
+
+  it('frac stays in [0,1) across events', () => {
+    const s = initWheelAccel(true, 1)
+
+    // Correctness invariant of fractional carry: never negative, never reaches 1.
+    for (let t = 1000; t < 1200; t += 30) {
+      computeWheelStep(s, 1, t)
+
+      expect(s.frac).toBeGreaterThanOrEqual(0)
+      expect(s.frac).toBeLessThan(1)
+    }
+  })
+})