protocol/contracts/staking/test/cobb_douglas.ts
Lawrence Forman 19f44fac1e @0x/contracts-staking: Reformulate cobb-douglas to be more efficient.
`@0x/contracts-staking`: Remove some unecessary asserts.
`@0x/contracts-staking`: Fix some broken test assertions.
`@0x/contracts-staking`: Generate better random values in tests.
`@0x/contracts-staking`: Rename `PPM_ONE` constant to `PPM_DENOMINATOR`.
`@0x/contracts-staking`: Minor solidity code improvements.
`@0x/contracts-staking`: Use more constants from `@0x/contracts-test-utils` in tests.
2019-09-04 20:18:55 -04:00

280 lines
13 KiB
TypeScript

import { blockchainTests, constants, expect, filterLogsToArguments } from '@0x/contracts-test-utils';
import { StakingRevertErrors } from '@0x/order-utils';
import { BigNumber, OwnableRevertErrors } from '@0x/utils';
import * as _ from 'lodash';
import {
artifacts,
TestCobbDouglasCobbDouglasAlphaChangedEventArgs,
TestCobbDouglasContract,
TestCobbDouglasEvents,
} from '../src/';
import { assertRoughlyEquals, getRandomInteger, getRandomPortion, Numberish, toDecimal } from './utils/number_utils';
// tslint:disable: no-unnecessary-type-assertion
blockchainTests('Cobb-Douglas', env => {
const FUZZ_COUNT = 1024;
const PRECISION = 15;
let testContract: TestCobbDouglasContract;
let ownerAddress: string;
let notOwnerAddress: string;
before(async () => {
[ownerAddress, notOwnerAddress] = await env.getAccountAddressesAsync();
testContract = await TestCobbDouglasContract.deployFrom0xArtifactAsync(
artifacts.TestCobbDouglas,
env.provider,
env.txDefaults,
artifacts,
);
});
blockchainTests.resets('setCobbDouglasAlpha()', () => {
const NEGATIVE_ONE = constants.MAX_UINT256.minus(1);
it('throws if not called by owner', async () => {
const [n, d] = [new BigNumber(1), new BigNumber(2)];
const tx = testContract.setCobbDouglasAlpha.awaitTransactionSuccessAsync(n, d, { from: notOwnerAddress });
const expectedError = new OwnableRevertErrors.OnlyOwnerError(notOwnerAddress, ownerAddress);
return expect(tx).to.revertWith(expectedError);
});
it('throws with int256(numerator) < 0', async () => {
const [n, d] = [NEGATIVE_ONE, NEGATIVE_ONE];
const tx = testContract.setCobbDouglasAlpha.awaitTransactionSuccessAsync(n, d);
const expectedError = new StakingRevertErrors.InvalidCobbDouglasAlphaError(n, d);
return expect(tx).to.revertWith(expectedError);
});
it('throws with int256(denominator) < 0', async () => {
const [n, d] = [new BigNumber(1), NEGATIVE_ONE];
const tx = testContract.setCobbDouglasAlpha.awaitTransactionSuccessAsync(n, d);
const expectedError = new StakingRevertErrors.InvalidCobbDouglasAlphaError(n, d);
return expect(tx).to.revertWith(expectedError);
});
it('throws with denominator == 0', async () => {
const [n, d] = [new BigNumber(0), new BigNumber(0)];
const tx = testContract.setCobbDouglasAlpha.awaitTransactionSuccessAsync(n, d);
const expectedError = new StakingRevertErrors.InvalidCobbDouglasAlphaError(n, d);
return expect(tx).to.revertWith(expectedError);
});
it('throws with numerator > denominator', async () => {
const [n, d] = [new BigNumber(2), new BigNumber(1)];
const tx = testContract.setCobbDouglasAlpha.awaitTransactionSuccessAsync(n, d);
const expectedError = new StakingRevertErrors.InvalidCobbDouglasAlphaError(n, d);
return expect(tx).to.revertWith(expectedError);
});
async function setCobbDouglasAlphaAndAssertEffectsAsync(n: Numberish, d: Numberish): Promise<void> {
const [_n, _d] = [new BigNumber(n), new BigNumber(d)];
const receipt = await testContract.setCobbDouglasAlpha.awaitTransactionSuccessAsync(_n, _d);
const logs = filterLogsToArguments<TestCobbDouglasCobbDouglasAlphaChangedEventArgs>(
receipt.logs,
TestCobbDouglasEvents.CobbDouglasAlphaChanged,
);
expect(logs.length).to.eq(1);
expect(logs[0].numerator).to.bignumber.eq(_n);
expect(logs[0].denominator).to.bignumber.eq(_d);
const [actualNumerator, actualDenominator] = await testContract.getCobbDouglasAlpha.callAsync();
expect(actualNumerator).to.bignumber.eq(_n);
expect(actualDenominator).to.bignumber.eq(_d);
}
it('accepts numerator == denominator', async () => {
return setCobbDouglasAlphaAndAssertEffectsAsync(1, 1);
});
it('accepts numerator < denominator', async () => {
return setCobbDouglasAlphaAndAssertEffectsAsync(1, 2);
});
it('accepts numerator == 0', async () => {
return setCobbDouglasAlphaAndAssertEffectsAsync(0, 1);
});
});
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 = 11e3;
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(toDecimal(1).minus(alpha)))
.times(toDecimal(totalRewards))
.toFixed(0, BigNumber.ROUND_FLOOR),
);
}
function getRandomParams(overrides?: Partial<CobbDouglasParams>): CobbDouglasParams {
const totalRewards = _.get(overrides, 'totalRewards', getRandomInteger(0, 1e27)) as Numberish;
const totalFees = _.get(overrides, 'totalFees', getRandomInteger(1, 1e27)) as Numberish;
const ownerFees = _.get(overrides, 'ownerFees', getRandomPortion(totalFees)) as Numberish;
const totalStake = _.get(overrides, 'totalStake', getRandomInteger(1, 1e27)) as Numberish;
const ownerStake = _.get(overrides, 'ownerStake', getRandomPortion(totalStake)) as Numberish;
const alphaDenominator = _.get(overrides, 'alphaDenominator', getRandomInteger(1, 1e6)) as Numberish;
const alphaNumerator = _.get(overrides, 'alphaNumerator', getRandomPortion(alphaDenominator)) as Numberish;
return {
totalRewards,
ownerFees,
totalFees,
ownerStake,
totalStake,
alphaNumerator,
alphaDenominator,
};
}
it('computes the correct reward', async () => {
const expected = cobbDouglas();
const r = await callCobbDouglasAsync();
assertRoughlyEquals(r, expected, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
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, PRECISION);
});
}
});
});
});
// tslint:enable:no-unnecessary-type-assertion