healer-man/src/game/combatSpellBlocking.test.ts

import { describe, expect, it } from "vitest";
import { resolveCombatResult, type CombatRollStage, type ResolveCombatResultInput } from "./combatResults";

function directSpell(overrides: Partial<ResolveCombatResultInput> = {}): ResolveCombatResultInput {
  return {
    amount: 100, attackKind: "melee", damageSchool: "physical",
    attacker: { level: 30, criticalChancePercent: 20 },
    defender: { level: 30, blockPercent: 80, blockValue: 15 },
    rules: { blockMode: "post-hit", canMiss: false },
    roll: (stage) => stage === "block" ? 0.1 : 0.8,
    ...overrides,
  };
}

describe("source direct spell post-hit block", () => {
  it("keeps block outside the attack table and independently mitigates a critical hit", () => {
    const result = resolveCombatResult(directSpell({ roll: () => 0.1 }));
    expect(result.attackTable.blockPercent).toBe(0);
    expect(result.attackTable.criticalPercent).toBe(20);
    expect(result).toMatchObject({ outcome: "crit", critical: true, blocked: true,
      damageBeforeMitigation: 200, blockedAmount: 15, finalDamage: 185,
      postHitBlockRoll: 0.1, postHitBlockChancePercent: 80 });
  });

  it("records a normal blocked hit and caps block value at remaining damage", () => {
    expect(resolveCombatResult(directSpell({ defender: { level: 30, blockPercent: 80, blockValue: 500 } })))
      .toMatchObject({ outcome: "block", critical: false, blocked: true, blockedAmount: 100, finalDamage: 0 });
  });

  it("does not reinterpret a failed independent block roll as an attack-table block", () => {
    expect(resolveCombatResult(directSpell({ roll: () => 0.9 })))
      .toMatchObject({ outcome: "hit", blocked: false, finalDamage: 100 });
  });

  it.each(["miss", "dodge", "parry", "immune"] as const)("does not roll a block after %s", (avoidance) => {
    const stages: CombatRollStage[] = [];
    const result = resolveCombatResult(directSpell({
      attacker: { level: 30, criticalChancePercent: 0 },
      defender: { level: 30, dodgePercent: avoidance === "dodge" ? 100 : 0,
        parryPercent: avoidance === "parry" ? 100 : 0, blockPercent: 100, blockValue: 15 },
      rules: { blockMode: "post-hit", canMiss: avoidance === "miss", immune: avoidance === "immune" },
      roll: (stage) => { stages.push(stage); return 0; },
    }));
    expect(result.landed).toBe(false);
    expect(stages).toEqual(["outcome"]);
    expect(result.blocked).toBe(false);
  });

  it.each([
    { damageSchool: "arcane" as const },
    { attackKind: "spell" as const },
    { rules: { blockMode: "post-hit" as const, canBlock: false, canMiss: false } },
  ])("requires a physical weapon packet and an enabled block rule: %j", (overrides) => {
    const stages: CombatRollStage[] = [];
    const result = resolveCombatResult(directSpell({ ...overrides,
      roll: (stage) => { stages.push(stage); return 0.8; } }));
    expect(result.blocked).toBe(false);
    expect(stages).toEqual(["outcome"]);
  });

  it("preserves the single-roll autoattack table", () => {
    const stages: CombatRollStage[] = [];
    const result = resolveCombatResult(directSpell({ rules: { isAutoAttack: true, canMiss: false },
      roll: (stage) => { stages.push(stage); return 0.1; } }));
    expect(result).toMatchObject({ outcome: "block", critical: false, blocked: true, finalDamage: 85 });
    expect(stages).toEqual(["outcome"]);
    expect(result.postHitBlockRoll).toBeUndefined();
  });
});

describe("source critical block roll", () => {
  it("doubles an attack-table block after an independent integer roll", () => {
    const stages: CombatRollStage[] = [];
    const result = resolveCombatResult(directSpell({
      attacker: { level: 30, criticalChancePercent: 0 },
      defender: { level: 30, blockPercent: 80, blockValue: 15, criticalBlockChancePercent: 20 },
      rules: { canMiss: false },
      roll: (stage) => {
        stages.push(stage);
        return stage === "outcome" ? 0.1 : 0.199;
      },
    }));

    expect(result).toMatchObject({ outcome: "block", blocked: true,
      blockedAmount: 30, finalDamage: 70, criticalBlockChancePercent: 20,
      criticalBlockRoll: 19, criticalBlocked: true });
    expect(stages).toEqual(["outcome", "critical-block"]);
  });

  it("doubles a successful post-hit block and samples after the ordinary block", () => {
    const stages: CombatRollStage[] = [];
    const result = resolveCombatResult(directSpell({
      defender: { level: 30, blockPercent: 80, blockValue: 15, criticalBlockChancePercent: 20 },
      roll: (stage) => {
        stages.push(stage);
        return stage === "outcome" ? 0.8 : stage === "block" ? 0.1 : 0.199;
      },
    }));

    expect(result).toMatchObject({ outcome: "block", blocked: true, blockedAmount: 30,
      finalDamage: 70, postHitBlockRoll: 0.1, criticalBlockRoll: 19, criticalBlocked: true });
    expect(stages).toEqual(["outcome", "block", "critical-block"]);
  });

  it("keeps ordinary block value when the independent integer roll fails", () => {
    const result = resolveCombatResult(directSpell({
      defender: { level: 30, blockPercent: 80, blockValue: 15, criticalBlockChancePercent: 20 },
      roll: (stage) => stage === "outcome" ? 0.8 : stage === "block" ? 0.1 : 0.2,
    }));

    expect(result).toMatchObject({ blocked: true, blockedAmount: 15, finalDamage: 85,
      criticalBlockRoll: 20, criticalBlocked: false });
  });

  it("does not roll critical block when the attack did not block", () => {
    const stages: CombatRollStage[] = [];
    const result = resolveCombatResult(directSpell({
      defender: { level: 30, blockPercent: 80, blockValue: 15, criticalBlockChancePercent: 100 },
      roll: (stage) => { stages.push(stage); return 0.99; },
    }));

    expect(result).toMatchObject({ outcome: "hit", blocked: false, blockedAmount: 0 });
    expect(result.criticalBlocked).toBeUndefined();
    expect(stages).toEqual(["outcome", "block"]);
  });

  it.each([
    { chance: 0, expected: false, blockedAmount: 15 },
    { chance: 100, expected: true, blockedAmount: 30 },
  ])("matches roll_chance_i at $chance percent while consuming its 0..99 sample", ({ chance, expected, blockedAmount }) => {
    const stages: CombatRollStage[] = [];
    const result = resolveCombatResult(directSpell({
      attacker: { level: 30, criticalChancePercent: 0 },
      defender: { level: 30, blockPercent: 80, blockValue: 15, criticalBlockChancePercent: chance },
      rules: { canMiss: false },
      roll: (stage) => { stages.push(stage); return stage === "outcome" ? 0.1 : 0.5; },
    }));

    expect(result).toMatchObject({ blocked: true, blockedAmount, criticalBlockChancePercent: chance,
      criticalBlockRoll: 50, criticalBlocked: expected });
    expect(stages).toEqual(["outcome", "critical-block"]);
  });
});