protocol/contracts/staking/test/cobb_douglas.ts

271 lines
11 KiB
TypeScript

import { blockchainTests, expect, hexRandom } from '@0x/contracts-test-utils';
import { AnyRevertError, BigNumber, FixedMathRevertErrors } from '@0x/utils';
import { Decimal } from 'decimal.js';
import * as _ from 'lodash';
import { artifacts, TestCobbDouglasContract } from '../src/';
Decimal.set({ precision: 128 });
type Numberish = BigNumber | string | number;
blockchainTests('Cobb-Douglas', env => {
const FUZZ_COUNT = 1024;
let testContract: TestCobbDouglasContract;
before(async () => {
testContract = await TestCobbDouglasContract.deployFrom0xArtifactAsync(
artifacts.TestCobbDouglas,
env.provider,
env.txDefaults,
artifacts,
);
});
function toPrecision(n: Numberish, precision: number): BigNumber {
const _n = new BigNumber(n);
const integerDigits = _n.integerValue().sd(true);
const base = 10 ** (precision - integerDigits);
return _n.times(base).integerValue(BigNumber.ROUND_FLOOR).dividedBy(base);
}
function toDecimal(x: Numberish): Decimal {
if (BigNumber.isBigNumber(x)) {
return new Decimal(x.toString(10));
}
return new Decimal(x);
}
function assertRoughlyEquals(
actual: Numberish,
expected: Numberish,
precision: number = 14,
): void {
// SD is not what we want.
expect(toPrecision(actual, precision)).to.bignumber.eq(toPrecision(expected, precision));
}
function getRandomAmount(min: Numberish, max: Numberish): BigNumber {
const range = new BigNumber(max).minus(min);
const random = new BigNumber(hexRandom().substr(2), 16);
return random.mod(range).plus(min);
}
function getRandomPortion(total: Numberish): BigNumber {
return new BigNumber(total).times(Math.random()).integerValue();
}
describe('cobbDouglas()', () => {
interface CobbDouglasParams {
totalRewards: Numberish;
ownerFees: Numberish;
totalFees: Numberish;
ownerStake: Numberish;
totalStake: Numberish;
alphaNumerator: Numberish;
alphaDenominator: Numberish;
gas?: number;
}
const MAX_COBB_DOUGLAS_GAS = 15e3;
const TX_GAS_FEE = 21e3;
const DEFAULT_COBB_DOUGLAS_PARAMS: CobbDouglasParams = {
totalRewards: 100e18,
ownerFees: 10e18,
totalFees: 500e18,
ownerStake: 1.1e21,
totalStake: 3e27,
alphaNumerator: 1,
alphaDenominator: 3,
gas: MAX_COBB_DOUGLAS_GAS,
};
async function callCobbDouglasAsync(params?: Partial<CobbDouglasParams>): Promise<BigNumber> {
const _params = {
...DEFAULT_COBB_DOUGLAS_PARAMS,
...params,
};
return testContract.cobbDouglas.callAsync(
new BigNumber(_params.totalRewards),
new BigNumber(_params.ownerFees),
new BigNumber(_params.totalFees),
new BigNumber(_params.ownerStake),
new BigNumber(_params.totalStake),
new BigNumber(_params.alphaNumerator),
new BigNumber(_params.alphaDenominator),
{
gas: TX_GAS_FEE + (_params.gas === undefined ? MAX_COBB_DOUGLAS_GAS : _params.gas),
},
);
}
function cobbDouglas(params?: Partial<CobbDouglasParams>): BigNumber {
const {
totalRewards,
ownerFees,
totalFees,
ownerStake,
totalStake,
alphaNumerator,
alphaDenominator,
} = {
...DEFAULT_COBB_DOUGLAS_PARAMS,
...params,
};
const feeRatio = toDecimal(ownerFees).dividedBy(toDecimal(totalFees));
const stakeRatio = toDecimal(ownerStake).dividedBy(toDecimal(totalStake));
const alpha = toDecimal(alphaNumerator).dividedBy(toDecimal(alphaDenominator));
// totalRewards * feeRatio ^ alpha * stakeRatio ^ (1-alpha)
return new BigNumber(
feeRatio.pow(alpha).times(
stakeRatio.pow(new Decimal(1).minus(alpha)),
).times(toDecimal(totalRewards)).toFixed(0, BigNumber.ROUND_FLOOR),
);
}
function getRandomParams(overrides?: Partial<CobbDouglasParams>): CobbDouglasParams {
const totalRewards = _.get(overrides, 'totalRewards', getRandomAmount(0, 1e27)) as Numberish;
const totalFees = _.get(overrides, 'totalFees', getRandomAmount(1, 1e27)) as Numberish;
const ownerFees = _.get(overrides, 'ownerFees', getRandomPortion(totalFees)) as Numberish;
const totalStake = _.get(overrides, 'totalStake', getRandomAmount(1, 1e27)) as Numberish;
const ownerStake = _.get(overrides, 'ownerStake', getRandomPortion(totalStake)) as Numberish;
const alphaDenominator = _.get(overrides, 'alphaDenominator', getRandomAmount(1, 1e6)) as Numberish;
const alphaNumerator = _.get(overrides, 'alphaNumerator', getRandomPortion(alphaDenominator)) as Numberish;
return {
totalRewards,
ownerFees,
totalFees,
ownerStake,
totalStake,
alphaNumerator,
alphaDenominator,
};
}
it('throws if `alphaNumerator` > `alphaDenominator`', async () => {
return expect(callCobbDouglasAsync({
alphaNumerator: 11,
alphaDenominator: 10,
})).to.revertWith(new AnyRevertError()); // Just an assertion failure.
});
it('throws if `ownerFees` > `totalFees`', async () => {
const expectedError = new FixedMathRevertErrors.FixedMathSignedValueError(
FixedMathRevertErrors.ValueErrorCodes.TooLarge,
);
return expect(callCobbDouglasAsync({
ownerFees: 11,
totalFees: 10,
})).to.revertWith(expectedError);
});
it('throws if `ownerStake` > `totalStake`', async () => {
const expectedError = new FixedMathRevertErrors.FixedMathSignedValueError(
FixedMathRevertErrors.ValueErrorCodes.TooLarge,
);
return expect(callCobbDouglasAsync({
ownerStake: 11,
totalStake: 10,
})).to.revertWith(expectedError);
});
it('computes the correct reward', async () => {
const expected = cobbDouglas();
const r = await callCobbDouglasAsync();
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with zero stake ratio', async () => {
const ownerStake = 0;
const expected = cobbDouglas({ ownerStake });
const r = await callCobbDouglasAsync({ ownerStake });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with full stake ratio', async () => {
const ownerStake = DEFAULT_COBB_DOUGLAS_PARAMS.totalStake;
const expected = cobbDouglas({ ownerStake });
const r = await callCobbDouglasAsync({ ownerStake });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with a very low stake ratio', async () => {
const ownerStake = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalStake).times(1e-18);
const expected = cobbDouglas({ ownerStake });
const r = await callCobbDouglasAsync({ ownerStake });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with a very high stake ratio', async () => {
const ownerStake = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalStake).times(1 - 1e-18);
const expected = cobbDouglas({ ownerStake });
const r = await callCobbDouglasAsync({ ownerStake });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with zero fee ratio', async () => {
const ownerFees = 0;
const expected = cobbDouglas({ ownerFees });
const r = await callCobbDouglasAsync({ ownerFees });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with full fee ratio', async () => {
const ownerFees = DEFAULT_COBB_DOUGLAS_PARAMS.totalFees;
const expected = cobbDouglas({ ownerFees });
const r = await callCobbDouglasAsync({ ownerFees });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with a very low fee ratio', async () => {
const ownerFees = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalFees).times(1e-18);
const expected = cobbDouglas({ ownerFees });
const r = await callCobbDouglasAsync({ ownerFees });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with a very high fee ratio', async () => {
const ownerFees = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalFees).times(1 - 1e-18);
const expected = cobbDouglas({ ownerFees });
const r = await callCobbDouglasAsync({ ownerFees });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with equal fee and stake ratios', async () => {
const ownerFees = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalFees).times(0.5);
const ownerStake = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalStake).times(0.5);
const expected = cobbDouglas({ ownerFees, ownerStake });
const r = await callCobbDouglasAsync({ ownerFees, ownerStake });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with full fee and stake ratios', async () => {
const ownerFees = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalFees);
const ownerStake = new BigNumber(DEFAULT_COBB_DOUGLAS_PARAMS.totalStake);
const expected = cobbDouglas({ ownerFees, ownerStake });
const r = await callCobbDouglasAsync({ ownerFees, ownerStake });
assertRoughlyEquals(r, expected);
});
it('computes the correct reward with zero fee and stake ratios', async () => {
const ownerFees = 0;
const ownerStake = 0;
const expected = cobbDouglas({ ownerFees, ownerStake });
const r = await callCobbDouglasAsync({ ownerFees, ownerStake });
assertRoughlyEquals(r, expected);
});
blockchainTests.optional('fuzzing', () => {
const inputs = _.times(FUZZ_COUNT, () => getRandomParams());
for (const params of inputs) {
it(`cobbDouglas(${JSON.stringify(params)})`, async () => {
const expected = cobbDouglas(params);
const r = await callCobbDouglasAsync(params);
assertRoughlyEquals(r, expected, 12);
});
}
});
});
});
// tslint:enable:no-unnecessary-type-assertion