@alcorexchange/alcor-swap-sdk/test/currencyAmount.test.ts

## Installation ​​ **npm** ``` npm i @alcorexchange/alcor-swap-sdk ``` **yarn** ``` yarn add @alcorexchange/alcor-swap-sdk ``` ## Usage ### Import:

import JSBI from "jsbi";
import { MaxUint256 } from "internalConstants";
import { Token } from "../src/entities/token";
import { CurrencyAmount } from "../src/entities/fractions/currencyAmount";
import { Percent } from "../src/entities/fractions/percent";

describe("CurrencyAmount", () => {
  const CONTRACT_ONE = "contracta";

  describe("constructor", () => {
    it("works", () => {
      const token = new Token(CONTRACT_ONE, 18, "ABC");
      const amount = CurrencyAmount.fromRawAmount(token, 100);
      expect(amount.quotient).toEqual(JSBI.BigInt(100));
    });
  });

  describe("#quotient", () => {
    it("returns the amount after multiplication", () => {
      const token = new Token(CONTRACT_ONE, 18, "ABC");
      const amount = CurrencyAmount.fromRawAmount(token, 100).multiply(
        new Percent(15, 100)
      );
      expect(amount.quotient).toEqual(JSBI.BigInt(15));
    });
  });

  it("token amount can be max uint256", () => {
    const amount = CurrencyAmount.fromRawAmount(
      new Token(CONTRACT_ONE, 18, "ABC"),
      MaxUint256
    );
    expect(amount.quotient).toEqual(MaxUint256);
  });
  it("token amount cannot exceed max uint256", () => {
    expect(() =>
      CurrencyAmount.fromRawAmount(
        new Token(CONTRACT_ONE, 18, "ABC"),
        JSBI.add(MaxUint256, JSBI.BigInt(1))
      )
    ).toThrow("AMOUNT");
  });
  it("token amount quotient cannot exceed max uint256", () => {
    expect(() =>
      CurrencyAmount.fromFractionalAmount(
        new Token(CONTRACT_ONE, 18, "ABC"),
        JSBI.add(JSBI.multiply(MaxUint256, JSBI.BigInt(2)), JSBI.BigInt(2)),
        JSBI.BigInt(2)
      )
    ).toThrow("AMOUNT");
  });
  it("token amount numerator can be gt. uint256 if denominator is gt. 1", () => {
    const amount = CurrencyAmount.fromFractionalAmount(
      new Token(CONTRACT_ONE, 18, "ABC"),
      JSBI.add(MaxUint256, JSBI.BigInt(2)),
      2
    );
    expect(amount.numerator).toEqual(JSBI.add(JSBI.BigInt(2), MaxUint256));
  });

  describe("#toFixed", () => {
    it("throws for decimals > currency.decimals", () => {
      const token = new Token(CONTRACT_ONE, 0, "CDE");
      const amount = CurrencyAmount.fromRawAmount(token, 1000);
      expect(() => amount.toFixed(3)).toThrow("DECIMALS");
    });
    it("is correct for 0 decimals", () => {
      const token = new Token(CONTRACT_ONE, 0, "CDE");
      const amount = CurrencyAmount.fromRawAmount(token, 123456);
      expect(amount.toFixed(0)).toEqual("123456");
    });
    it("is correct for 18 decimals", () => {
      const token = new Token(CONTRACT_ONE, 18, "ABC");
      const amount = CurrencyAmount.fromRawAmount(token, 1e15);
      expect(amount.toFixed(9)).toEqual("0.001000000");
    });
  });

  describe("#toSignificant", () => {
    it("does not throw for sig figs > currency.decimals", () => {
      const token = new Token(CONTRACT_ONE, 0, "CDE");
      const amount = CurrencyAmount.fromRawAmount(token, 1000);
      expect(amount.toSignificant(3)).toEqual("1000");
    });
    it("is correct for 0 decimals", () => {
      const token = new Token(CONTRACT_ONE, 0, "CDE");
      const amount = CurrencyAmount.fromRawAmount(token, 123456);
      expect(amount.toSignificant(4)).toEqual("123400");
    });
    it("is correct for 18 decimals", () => {
      const token = new Token(CONTRACT_ONE, 18, "ABC");
      const amount = CurrencyAmount.fromRawAmount(token, 1e15);
      expect(amount.toSignificant(9)).toEqual("0.001");
    });
  });

  describe("#toExact", () => {
    it("does not throw for sig figs > currency.decimals", () => {
      const token = new Token(CONTRACT_ONE, 0, "CDE");
      const amount = CurrencyAmount.fromRawAmount(token, 1000);
      expect(amount.toExact()).toEqual("1000");
    });
    it("is correct for 0 decimals", () => {
      const token = new Token(CONTRACT_ONE, 0, "CDE");
      const amount = CurrencyAmount.fromRawAmount(token, 123456);
      expect(amount.toExact()).toEqual("123456");
    });
    it("is correct for 18 decimals", () => {
      const token = new Token(CONTRACT_ONE, 18, "ABC");
      const amount = CurrencyAmount.fromRawAmount(token, 123e13);
      expect(amount.toExact()).toEqual("0.00123");
    });
  });
});