heros_web/scripts/verify-battle-forecast.mjs

import assert from 'node:assert/strict';
import { readFile } from 'node:fs/promises';
import { createServer } from 'vite';

const server = await createServer({
  logLevel: 'error',
  server: { host: '127.0.0.1', port: 0, hmr: false },
  appType: 'custom'
});

try {
  const {
    buildCombatExchangeProjection,
    compareMoveIntentRisk,
    summarizeIntentRisk
  } = await server.ssrLoadModule('/src/game/data/battleForecast.ts');

  const before = [
    { enemyId: 'e1', kind: 'attack', targetId: 'ally', damage: 20, hitRate: 80 },
    { enemyId: 'e2', kind: 'usable', targetId: 'ally', damage: 10, hitRate: 100 },
    { enemyId: 'e3', kind: 'approach', targetId: 'ally', damage: 0, hitRate: 0 }
  ];
  const afterSaferMove = [
    { enemyId: 'e1', kind: 'approach', targetId: 'ally', damage: 0, hitRate: 0 },
    { enemyId: 'e2', kind: 'attack', targetId: 'other', damage: 10, hitRate: 100 },
    { enemyId: 'e3', kind: 'approach', targetId: 'ally', damage: 0, hitRate: 0 }
  ];

  assert.deepEqual(
    summarizeIntentRisk(before, 'ally', 25),
    {
      immediateCount: 2,
      approachCount: 1,
      expectedDamage: 26,
      rawDamage: 30,
      criticalAdjustedMaxDamage: 30,
      lethal: true,
      immediateEnemyIds: ['e1', 'e2']
    },
    'Intent risk must distinguish immediate damage from approaching enemies.'
  );

  const safer = compareMoveIntentRisk(before, afterSaferMove, 'ally', 25);
  assert.equal(safer.tone, 'safer', 'Breaking an immediate attack line must be marked safer.');
  assert.equal(safer.immediateDelta, -2, 'Move preview must report removed immediate attackers.');
  assert.equal(safer.expectedDamageDelta, -26, 'Move preview must report the selected unit damage delta.');
  assert.equal(safer.retargetedAwayCount, 1, 'Move preview must report enemies redirected away from the mover.');
  assert.equal(safer.neutralizedImmediateCount, 1, 'Move preview must report an immediate attack converted to approach.');

  const afterRiskierMove = [
    ...before,
    { enemyId: 'e4', kind: 'attack', targetId: 'ally', damage: 12, hitRate: 75 }
  ];
  const riskier = compareMoveIntentRisk(before, afterRiskierMove, 'ally', 25);
  assert.equal(riskier.tone, 'riskier', 'A new incoming attack must be marked riskier.');
  assert.equal(riskier.immediateDelta, 1);
  assert.equal(riskier.expectedDamageDelta, 9);
  assert.equal(riskier.retargetedToCount, 1);

  const criticalIntent = summarizeIntentRisk(
    [{ enemyId: 'critical-enemy', kind: 'attack', targetId: 'ally', damage: 11, hitRate: 100, criticalRate: 20 }],
    'ally',
    15
  );
  assert.equal(criticalIntent.expectedDamage, 12, 'Intent expected damage must include critical probability.');
  assert.equal(criticalIntent.criticalAdjustedMaxDamage, 17, 'Intent maximum damage must match the real 1.5x rounded critical rule.');
  assert.equal(criticalIntent.lethal, true, 'A possible critical defeat must be exposed as lethal risk.');

  const exchange = buildCombatExchangeProjection({
    attackerHp: 34,
    defenderHp: 30,
    attackDamage: 18,
    attackHitRate: 90,
    attackCriticalRate: 10,
    counter: { damage: 12, hitRate: 80, criticalRate: 5 }
  });
  assert.equal(exchange.defenderHpAfterHit, 12);
  assert.equal(exchange.attackerHpAfterCounterHit, 22);
  assert.equal(exchange.counterCondition, 'if-defender-survives');
  assert.equal(exchange.attackLethalOnHit, false);
  assert.equal(exchange.counterLethalOnHit, false);
  assert.ok(exchange.attackExpectedDamage > exchange.counterExpectedDamage);

  const lethalExchange = buildCombatExchangeProjection({
    attackerHp: 10,
    defenderHp: 16,
    attackDamage: 18,
    attackHitRate: 90,
    attackCriticalRate: 10,
    counter: { damage: 12, hitRate: 80, criticalRate: 5 }
  });
  assert.equal(lethalExchange.defenderHpAfterHit, 0);
  assert.equal(lethalExchange.counterCondition, 'on-primary-miss', 'A lethal hit must explain that only a miss permits counterattack.');
  assert.equal(lethalExchange.counterLethalOnHit, true, 'Counter forecast must expose attacker defeat risk.');

  const criticalCounterExchange = buildCombatExchangeProjection({
    attackerHp: 15,
    defenderHp: 30,
    attackDamage: 8,
    attackHitRate: 100,
    attackCriticalRate: 0,
    counter: { damage: 11, hitRate: 90, criticalRate: 20 }
  });
  assert.equal(criticalCounterExchange.attackerHpAfterCounterHit, 4);
  assert.equal(criticalCounterExchange.attackerHpAfterCounterCriticalHit, 0);
  assert.equal(criticalCounterExchange.counterLethalOnHit, false);
  assert.equal(criticalCounterExchange.counterLethalOnCritical, true, 'Counter forecast must expose critical-only defeat risk.');

  const noCounter = buildCombatExchangeProjection({
    attackerHp: 20,
    defenderHp: 20,
    attackDamage: 8,
    attackHitRate: 85,
    attackCriticalRate: 5
  });
  assert.equal(noCounter.counterCondition, 'none');
  assert.equal(noCounter.attackerHpAfterCounterHit, 20);
  assert.equal(noCounter.counterExpectedDamage, 0);

  const battleSceneSource = await readFile(new URL('../src/game/scenes/BattleScene.ts', import.meta.url), 'utf8');
  assert.match(battleSceneSource, /moveIntentRiskForTile\(unit, tile\.x, tile\.y\)/, 'Move hover must invoke intent comparison.');
  assert.match(battleSceneSource, /handleBattleKeyboardNavigation\(event\)/, 'Keyboard navigation must remain wired.');
  assert.match(battleSceneSource, /combatPreview\(preview\.defender, preview\.attacker, 'attack', undefined, true\)/, 'Exchange forecast must reuse counter combat rules.');
  assert.match(battleSceneSource, /combatExchangeCounterMetric\(exchange\)/, 'Target cards must show numeric counter data.');
  assert.match(battleSceneSource, /criticalRate: plan\.preview\?\.criticalRate \?\? 0/, 'Move risk snapshots must retain enemy critical rates.');
  assert.match(battleSceneSource, /counterLethalOnCritical/, 'Counter UI must surface critical-only defeat risk.');

  console.log('Verified critical-aware move-intent deltas, exchange projections, keyboard wiring, and counter-rule reuse.');
} finally {
  await server.close();
}