/** * Diablo II: Lord of Destruction v1.13c — Skill #059: Blizzard * Empirical Stress Testing & Adversarial Verification Suite * * Requirements (User Request & Solution Stress Testing Playbook): * 1. Altitude descent: 120 px to 0 px over 9 ticks (linear 120/9 px/tick, clamped at 0). * 2. Ground impact explosion at tick 9 vs immediate explosion on monster collision at tick t < 9. * 3. NextDelay = 0: multiple shards hitting the same target deal damage without cooldown immunity * (both simultaneous hits and consecutive tick hits, with differential oracle contrast). * 4. Wall collisions: shards hitting walls explode and terminate cleanly without memory leak or hanging. * 5. 100,000 tick continuous stress simulation: verifying stability, bounded active missile count, * zero NaNs, zero crashes, and zero memory leaks over 2,222+ Blizzard casts. */ import { describe, expect, it } from 'vitest' import { tickProjectiles, ISO_GROUND_ASPECT_RATIO, calculateBlizzardDamage, calculateBlizzardSynergyMultiplier, CANONICAL_113C_MISSILES, type Projectile, type ProjectileTarget, } from '../src/game/skills.ts' import { BLIZZARD_CIRCLE_X, BLIZZARD_CIRCLE_Y, getBlizzardDropOffset, } from '../src/game/engine/blizzard-table.ts' import { MissileEngine } from '../src/game/engine/missile-engine.ts' import { getSharedDataRegistry } from '../src/game/engine/data-registry.ts' import { UnitStatList } from '../src/game/engine/stat-list.ts' import { StateBus } from '../src/game/engine/state-bus.ts' import type { CombatUnitContext } from '../src/game/engine/combat-pipeline.ts' import { drawMissileProjectile } from '../src/scene/act-scene.ts' describe('[Skill #059] Blizzard — Empirical Stress & Physics Challenger Suite', () => { const openTerrain = { overlap: () => 0 } const wallTerrain = { overlap: () => 1 } // ========================================================================= // Dimension 1: Shard Altitude Descent Physics (120 px -> 0 px over 9 ticks) // ========================================================================= describe('Dimension 1: Shard Altitude Descent Physics (120 px -> 0 px over 9 ticks)', () => { const shardVariants = ['blizzard1', 'blizzard2', 'blizzard3', 'blizzard4'] as const for (const variant of shardVariants) { it(`verifies altitude descent of ${variant} tick-by-tick from 120 px to 0 px over exactly 9 ticks`, () => { let shard: Projectile = { skillId: '59', x: 200, y: 200, vx: 0, vy: 0, altitude: 120, damage: 100, ttl: 9, fromPlayer: true, missileType: variant, } const descentRate = 120 / 9 // 13.333333333333334 px/tick for (let tick = 1; tick <= 9; tick++) { const outcome = tickProjectiles([shard], [], openTerrain) shard = outcome.alive.find(p => p.missileType === variant)! expect(shard).toBeDefined() expect(shard.ttl).toBe(9 - tick) const expectedAltitude = Math.max(0, 120 - tick * descentRate) expect(shard.altitude).toBeCloseTo(expectedAltitude, 0.001) if (tick === 9) { // At tick 9, altitude reaches ground level (within IEEE-754 float precision ~1e-14) expect(shard.altitude).toBeCloseTo(0, 5) expect(shard.ttl).toBe(0) } else { expect(shard.altitude).toBeGreaterThan(0) } } }) } it('verifies altitude never drops below zero and remains non-negative even if ticked past 0', () => { let shard: Projectile = { skillId: '59', x: 100, y: 100, vx: 0, vy: 0, altitude: 5, // very close to ground damage: 100, ttl: 5, fromPlayer: true, missileType: 'blizzard1', } // Tick once: 5 - (120/9) < 0, must be clamped to exactly 0 const outcome = tickProjectiles([shard], [], openTerrain) const ticked = outcome.alive.find(p => p.missileType === 'blizzard1')! expect(ticked.altitude).toBe(0) expect(Number.isNaN(ticked.altitude!)).toBe(false) expect(Number.isFinite(ticked.altitude!)).toBe(true) }) it('verifies visual screen projection offset: drawY = WorldY - altitude', () => { const drawnSprites: { x: number; y: number }[] = [] const mockRenderer = { draw: (_frame: any, x: number, y: number) => { drawnSprites.push({ x, y }) }, drawSolid: (_x: number, _y: number) => {}, } as any const mockArt = { meta: { name: 'blizzard1', directions: 1, framesPerDirection: 6, animSpeed: 16 }, frames: { 0: [{ anchorX: 0, anchorY: 0, width: 32, height: 64 }] }, handle: 'atlas', } as any // Shard at World (200, 200), altitude 120 -> screen Y should be 200 - 120 = 80 const shardHigh: Projectile = { skillId: '59', x: 200, y: 200, vx: 0, vy: 0, altitude: 120, damage: 100, ttl: 9, fromPlayer: true, missileType: 'blizzard1', } drawMissileProjectile(mockRenderer, shardHigh, mockArt) expect(drawnSprites.length).toBe(1) expect(drawnSprites[0]!.y).toBe(200 - 120) // 80 px // Shard at World (200, 200), altitude 0 (ground level) -> screen Y should be 200 drawnSprites.length = 0 const shardGround: Projectile = { ...shardHigh, altitude: 0, ttl: 0, } drawMissileProjectile(mockRenderer, shardGround, mockArt) expect(drawnSprites.length).toBe(1) expect(drawnSprites[0]!.y).toBe(200) // 200 px }) it('verifies all 25 shards spawned from blizzardcenter initialize with altitude 120 px', () => { const center: Projectile = { skillId: '59', x: 300, y: 300, vx: 0, vy: 0, damage: 200, ttl: 100, fromPlayer: true, missileType: 'blizzardcenter', subMissileIdx: 0, } let current: Projectile[] = [center] const spawnedShards: Projectile[] = [] for (let t = 1; t <= 100; t++) { const res = tickProjectiles(current, [], openTerrain) current = res.alive as Projectile[] if (res.spawnedProjectiles && res.spawnedProjectiles.length > 0) { for (const p of res.spawnedProjectiles) { if (p.missileType?.startsWith('blizzard') && !p.missileType.includes('explode')) { spawnedShards.push(p) } } } } expect(spawnedShards.length).toBe(25) for (const shard of spawnedShards) { expect(shard.altitude).toBe(120) expect(shard.ttl).toBe(9) expect(shard.damage).toBe(200) expect(shard.statusEffect).toBe('chill') expect(shard.statusDuration).toBe(100) } }) }) // ========================================================================= // Dimension 2: Ground Impact Explosion (t = 9) vs Immediate Collision (t < 9) // ========================================================================= describe('Dimension 2: Ground Impact Explosion (t = 9) vs Immediate Collision (t < 9)', () => { it('Case A (Ground Impact): shard reaches altitude 0 at tick 9 and detonates ground impact explosion on expiry', () => { let shard: Projectile = { skillId: '59', x: 250, y: 250, vx: 0, vy: 0, altitude: 120, damage: 150, ttl: 9, fromPlayer: true, missileType: 'blizzard1', } // Over ticks 1..9, no monster is present for (let tick = 1; tick <= 9; tick++) { const res = tickProjectiles([shard], [], openTerrain) expect(res.hits.length).toBe(0) expect(res.expired).toBe(0) shard = res.alive.find(p => p.missileType === 'blizzard1')! expect(shard).toBeDefined() } // At tick 9, shard is at ground level (altitude ~0 within IEEE-754 precision, ttl 0) expect(shard.altitude).toBeCloseTo(0, 5) expect(shard.ttl).toBe(0) // On next tick (tick 10), shard expires and detonates ground explosion const detonateRes = tickProjectiles([shard], [], openTerrain) expect(detonateRes.expired).toBe(1) expect(detonateRes.alive.some(p => p.missileType === 'blizzard1')).toBe(false) expect(detonateRes.spawnedProjectiles).toBeDefined() expect(detonateRes.spawnedProjectiles!.length).toBe(1) const exp = detonateRes.spawnedProjectiles![0]! expect(exp.missileType).toBe('blizzardexplode1') expect(exp.ttl).toBe(6) // 1.13c Range = 6 expect(exp.statusEffect).toBe('chill') expect(exp.statusDuration).toBe(100) // 1.13c ElemLen = 100 expect(exp.x).toBe(250) expect(exp.y).toBe(250) }) it('Case B (Immediate Monster Collision at t < 9): parametric sweep across all ticks t in [1..8]', () => { // Test collision at every possible mid-air tick: t = 1, 2, 3, 4, 5, 6, 7, 8 for (let collisionTick = 1; collisionTick <= 8; collisionTick++) { let shard: Projectile = { skillId: '59', x: 200, y: 200, vx: 0, vy: 0, altitude: 120, damage: 120, ttl: 9, fromPlayer: true, missileType: 'blizzard2', } // Ticks before collision: target is distant/inactive const distantTarget: ProjectileTarget = { index: 1, x: 9999, y: 9999, radius: 20, alive: true } for (let t = 1; t < collisionTick; t++) { const res = tickProjectiles([shard], [distantTarget], openTerrain) expect(res.hits.length).toBe(0) shard = res.alive.find(p => p.missileType === 'blizzard2')! expect(shard).toBeDefined() expect(shard.altitude).toBeGreaterThan(0) } // At collisionTick, place target directly under the falling shard const closeTarget: ProjectileTarget = { index: 1, x: 200, y: 200, radius: 20, alive: true } const hitRes = tickProjectiles([shard], [closeTarget], openTerrain) // 1. Hit must register IMMEDIATELY at collisionTick expect(hitRes.hits.length).toBe(1) const hit = hitRes.hits[0]! expect(hit.targetIndex).toBe(1) expect(hit.damage).toBe(120) expect(hit.statusEffect).toBe('chill') expect(hit.statusDuration).toBe(100) // 2. Shard must be destroyed IMMEDIATELY on collision (not survive to tick 9) expect(hitRes.alive.some(p => p.missileType === 'blizzard2')).toBe(false) // 3. Impact explosion must be spawned IMMEDIATELY at collisionTick expect(hitRes.spawnedProjectiles).toBeDefined() expect(hitRes.spawnedProjectiles!.length).toBe(1) const exp = hitRes.spawnedProjectiles![0]! expect(exp.missileType).toBe('blizzardexplode2') expect(exp.ttl).toBe(6) expect(exp.x).toBe(200) expect(exp.y).toBe(200) } }) it('empirical finding: blizzardexplode spawned on monster hit carries damage: 0 to prevent double damage', () => { const shard: Projectile = { skillId: '59', x: 200, y: 200, vx: 0, vy: 0, altitude: 60, damage: 150, ttl: 4, fromPlayer: true, missileType: 'blizzard3', } const target: ProjectileTarget = { index: 1, x: 200, y: 200, radius: 20, alive: true } const res = tickProjectiles([shard], [target], openTerrain) expect(res.hits.length).toBe(1) expect(res.hits[0]!.damage).toBe(150) // shard dealt full damage // Spawned explosion must have damage = 0 const exp = res.spawnedProjectiles![0]! expect(exp.missileType).toBe('blizzardexplode3') expect(exp.damage).toBe(0) }) }) // ========================================================================= // Dimension 3: NextDelay = 0 Invariant (No Cooldown Immunity / Sweet-Spot Burst) // ========================================================================= describe('Dimension 3: NextDelay = 0 Invariant (No Cooldown Immunity / Sweet-Spot Burst)', () => { it('verifies simultaneous hits: 5 overlapping shards hitting the same target on the same tick all deal full damage', () => { const shards: Projectile[] = [1, 2, 3, 4, 5].map(i => ({ skillId: '59', x: 200, y: 200, vx: 0, vy: 0, damage: 100, ttl: 5, fromPlayer: true, missileType: `blizzard${((i - 1) % 4) + 1}`, })) const target: ProjectileTarget = { index: 99, x: 200, y: 200, radius: 20, alive: true } const res = tickProjectiles(shards, [target], openTerrain) // All 5 shards must hit the target without being blocked by immunity frames expect(res.hits.length).toBe(5) let totalDamage = 0 for (const hit of res.hits) { expect(hit.targetIndex).toBe(99) expect(hit.damage).toBe(100) expect(hit.statusEffect).toBe('chill') totalDamage += hit.damage } expect(totalDamage).toBe(500) }) it('verifies consecutive tick hits: shards hitting on ticks t, t+1, t+2, t+3 all deal damage without NextDelay lockout', () => { const target: ProjectileTarget = { index: 42, x: 200, y: 200, radius: 20, alive: true } let totalDamage = 0 const recordedHits: number[] = [] // On 4 consecutive ticks, a new shard hits the target for (let t = 1; t <= 4; t++) { const shard: Projectile = { skillId: '59', x: 200, y: 200, vx: 0, vy: 0, damage: 150, ttl: 5, fromPlayer: true, missileType: 'blizzard1', } const res = tickProjectiles([shard], [target], openTerrain) expect(res.hits.length).toBe(1) expect(res.hits[0]!.damage).toBe(150) recordedHits.push(res.hits[0]!.damage) totalDamage += res.hits[0]!.damage } expect(recordedHits.length).toBe(4) expect(totalDamage).toBe(600) // 150 * 4 }) it('differential contrast oracle: compares NextDelay = 0 (Blizzard) against NextDelay = 4 (Nova / Chain Lightning)', async () => { const registry = await getSharedDataRegistry() const engine = new MissileEngine(registry) const ownerStatList = new UnitStatList(registry, {}) const owner: CombatUnitContext = { id: 'sorc', name: 'Sorceress', isUndead: false, isDemon: false, statList: ownerStatList, stateBus: new StateBus(ownerStatList, registry), } const dummyStatList = new UnitStatList(registry, { maxhp: 50000 * 256, hitpoints: 50000 * 256 }) const dummy: CombatUnitContext = { id: 'boss-target', name: 'BossDummy', isUndead: false, isDemon: true, statList: dummyStatList, stateBus: new StateBus(dummyStatList, registry), } const targetPositions = new Map([['boss-target', { x: 100, y: 100 }]]) // 1. Contrast Test: Nova with nextDelay = 4 // Spawn 2 Nova missiles hitting on tick 1 and tick 2 engine.spawnMissile({ missileNameOrId: 'nova', sourceSkillId: 48, slvl: 20, owner, startX: 100, startY: 100, targetX: 100, targetY: 100, dmgPacket: { skillId: 48, attackKind: 'spell', elemType: 'ltng', elemMin256: 100 * 256, elemMax256: 100 * 256, autoHit: true }, }) engine.spawnMissile({ missileNameOrId: 'nova', sourceSkillId: 48, slvl: 20, owner, startX: 100, startY: 100, targetX: 100, targetY: 100, dmgPacket: { skillId: 48, attackKind: 'spell', elemType: 'ltng', elemMin256: 100 * 256, elemMax256: 100 * 256, autoHit: true }, }) const novaRes = engine.tick(1, [dummy], targetPositions) // Under NextDelay = 4, first Nova hits, second Nova is locked out on the same tick! expect(novaRes.hits.length).toBe(1) expect(engine.isTargetInNextDelay('boss-target', 1)).toBe(true) // 2. Blizzard Test: NextDelay = 0 // In contrast, Blizzard has NextDelay = 0 (empty in Missiles.txt) const b1 = registry.getMissileByName('blizzard1')! expect(b1.nextHit).toBe(false) expect(b1.nextDelay).toBe(0) }) }) // ========================================================================= // Dimension 4: Wall Collisions & Resource Cleanup // ========================================================================= describe('Dimension 4: Wall Collisions & Resource Cleanup', () => { it('verifies descending shard hitting a wall detonates immediately and spawns impact explosion', () => { const shard: Projectile = { skillId: '59', x: 150, y: 150, vx: 0, vy: 0, altitude: 70, damage: 100, ttl: 6, fromPlayer: true, missileType: 'blizzard4', } const res = tickProjectiles([shard], [], wallTerrain) // Shard halted and destroyed by wall expect(res.wallHits).toBe(1) expect(res.alive.some(p => p.missileType === 'blizzard4')).toBe(false) // Wall hit event recorded expect(res.wallHitEvents).toBeDefined() expect(res.wallHitEvents!.length).toBe(1) expect(res.wallHitEvents![0]!.missileType).toBe('blizzard4') // Explosion spawned expect(res.spawnedProjectiles).toBeDefined() expect(res.spawnedProjectiles!.length).toBe(1) const exp = res.spawnedProjectiles![0]! expect(exp.missileType).toBe('blizzardexplode1') expect(exp.ttl).toBe(6) }) it('verifies 1,000 shards fired into solid walls terminate cleanly without memory leak or hanging', () => { const shards: Projectile[] = [] for (let i = 0; i < 1000; i++) { shards.push({ skillId: '59', x: 100 + (i % 50), y: 100 + Math.floor(i / 50), vx: 0, vy: 0, altitude: 120, damage: 50, ttl: 9, fromPlayer: true, missileType: 'blizzard1', }) } // Tick 1: all 1,000 shards strike the wall immediately const tick1 = tickProjectiles(shards, [], wallTerrain) expect(tick1.wallHits).toBe(1000) // None of the original shards should survive expect(tick1.alive.every(p => p.missileType === 'blizzardexplode1')).toBe(true) expect(tick1.alive.length).toBe(1000) // 1,000 spawned explosions // Now tick the 1,000 explosions over open terrain until they all expire (range = 6) let active = tick1.alive as Projectile[] for (let t = 1; t <= 6; t++) { const step = tickProjectiles(active, [], openTerrain) active = step.alive as Projectile[] } // After 6 ticks, the explosions reached ttl = 0 // Next tick (tick 7): all 1,000 explosions expire const finalStep = tickProjectiles(active, [], openTerrain) expect(finalStep.expired).toBe(1000) expect(finalStep.alive.length).toBe(0) // Clean zero active missiles! }) }) // ========================================================================= // Dimension 5: 100,000-Tick Long-Run Stress Simulation (Crashes, NaNs, Leaks) // ========================================================================= describe('Dimension 5: 100,000-Tick Long-Run Stress Simulation (Crashes, NaNs, Leaks)', () => { it('runs 100,000 ticks of continuous Blizzard casting without crashes, NaNs, or memory leaks', () => { const simStartMs = Date.now() const heapBefore = process.memoryUsage().heapUsed let activeProjectiles: Projectile[] = [] let totalCasts = 0 let totalHits = 0 let totalWallHits = 0 let totalExpired = 0 let peakActiveCount = 0 // Dynamic targets moving in combat arena const targets: ProjectileTarget[] = [ { index: 0, x: 200, y: 200, radius: 25, alive: true }, { index: 1, x: 215, y: 210, radius: 20, alive: true }, { index: 2, x: 190, y: 220, radius: 20, alive: true }, { index: 3, x: 205, y: 185, radius: 20, alive: true }, { index: 4, x: 300, y: 300, radius: 25, alive: true }, ] // Semi-solid map terrain with boundary walls const hybridTerrain = { overlap: (x: number, y: number) => (x > 380 || x < 20 || y > 380 || y < 20 ? 1 : 0), } // 100,000 ticks = 4,000 seconds = 66.6 minutes of non-stop game simulation for (let tick = 0; tick < 100000; tick++) { // Cast Blizzard on cooldown (every 45 ticks = 1.80s cast delay) if (tick % 45 === 0) { totalCasts++ // Settle Blizzard center with slight spatial variation across casts const cx = 200 + ((tick / 45) % 5) * 10 const cy = 200 + ((tick / 45) % 7) * 8 activeProjectiles.push({ skillId: '59', x: cx, y: cy, vx: 0, vy: 0, damage: 150, ttl: 100, fromPlayer: true, missileType: 'blizzardcenter', subMissileIdx: 0, }) } // Monsters oscillate positions slightly every 10 ticks if (tick % 10 === 0) { for (let m = 0; m < targets.length; m++) { const angle = (tick * 0.05) + m targets[m] = { ...targets[m]!, x: 200 + Math.cos(angle) * 30, y: 200 + Math.sin(angle) * 15 * ISO_GROUND_ASPECT_RATIO, } } } // Advance simulation tick const outcome = tickProjectiles(activeProjectiles, targets, hybridTerrain) activeProjectiles = outcome.alive as Projectile[] totalHits += outcome.hits.length totalWallHits += outcome.wallHits totalExpired += outcome.expired if (activeProjectiles.length > peakActiveCount) { peakActiveCount = activeProjectiles.length } // INVARIANT 1: Bounded missile count — no runaway memory leak! // At any tick, at most 3 blizzard centers (ttl 100 / 45 = 2.22) can exist concurrently, // each emitting shards with ttl 9. Peak active projectiles must never exceed 60. if (activeProjectiles.length > 60) { throw new Error(`Memory leak detected at tick ${tick}: active projectile count reached ${activeProjectiles.length}`) } // INVARIANT 2: Zero NaNs or non-finite numbers in any active missile for (const p of activeProjectiles) { if (!Number.isFinite(p.x) || !Number.isFinite(p.y)) { throw new Error(`NaN detected in position at tick ${tick}: x=${p.x}, y=${p.y}`) } if (p.altitude !== undefined && (!Number.isFinite(p.altitude) || p.altitude < 0)) { throw new Error(`Invalid altitude at tick ${tick}: altitude=${p.altitude}`) } if (!Number.isFinite(p.ttl) || p.ttl < 0) { throw new Error(`Invalid ttl at tick ${tick}: ttl=${p.ttl}`) } } } const simElapsedMs = Date.now() - simStartMs const heapAfter = process.memoryUsage().heapUsed const heapDiffMb = (heapAfter - heapBefore) / (1024 * 1024) // Assertions on 100,000 tick completion expect(totalCasts).toBe(Math.floor(100000 / 45) + 1) // 2,223 Blizzard casts expect(totalHits).toBeGreaterThan(1000) // thousands of hits registered expect(peakActiveCount).toBeLessThanOrEqual(45) // comfortably bounded expect(activeProjectiles.length).toBeLessThanOrEqual(25) // final active count is bounded expect(heapDiffMb).toBeLessThan(15) // stable heap (< 15 MB variance) console.log(`[100,000-Tick Blizzard Stress Sim Completed]`) console.log(` Duration: ${simElapsedMs} ms (${(100000 / (simElapsedMs / 1000)).toFixed(0)} ticks/sec)`) console.log(` Total Casts: ${totalCasts}`) console.log(` Total Hits: ${totalHits}`) console.log(` Total Wall Hits: ${totalWallHits}`) console.log(` Total Expired Missiles: ${totalExpired}`) console.log(` Peak Active Projectiles: ${peakActiveCount}`) console.log(` Final Active Projectiles: ${activeProjectiles.length}`) console.log(` Heap Diff: ${heapDiffMb.toFixed(2)} MB`) }) }) })