import { describe, it, expect } from "vitest";
import { evaluateSlippage } from "../../../src/guards/slippage.js";
import { Guard } from "../../../src/strategy.schema.js";

describe("Slippage Guard", () => {
  it("should pass when slippage is within limit", () => {
    const guard: Guard = {
      type: "slippage",
      params: {
        maxBps: 50, // 0.5%
      },
    };

    const context = {
      expectedAmount: 1000000n,
      actualAmount: 995000n, // 0.5% slippage
    };

    const result = evaluateSlippage(guard, context);
    expect(result.passed).toBe(true);
  });

  it("should fail when slippage exceeds limit", () => {
    const guard: Guard = {
      type: "slippage",
      params: {
        maxBps: 10, // 0.1%
      },
    };

    const context = {
      expectedAmount: 1000000n,
      actualAmount: 980000n, // 2% slippage
    };

    const result = evaluateSlippage(guard, context);
    expect(result.passed).toBe(false);
    expect(result.reason).toContain("slippage");
  });

  it("should handle zero expected amount", () => {
    const guard: Guard = {
      type: "slippage",
      params: {
        maxBps: 50,
      },
    };

    const context = {
      expectedAmount: 0n,
      actualAmount: 995000n,
    };

    const result = evaluateSlippage(guard, context);
    // Should fail if expected amount is zero
    expect(result.passed).toBe(false);
    expect(result.reason).toContain("zero");
  });
});