Refactor Time library to use valueBefore/valueAfter (#4555)

Co-authored-by: Francisco <fg@frang.io>

test/utils/types/Time.test.js

@@ -0,0 +1,161 @@
+require('@openzeppelin/test-helpers');
+
+const { expect } = require('chai');
+const { clock } = require('../../helpers/time');
+const { product, max } = require('../../helpers/iterate');
+
+const Time = artifacts.require('$Time');
+
+const MAX_UINT32 = 1n << (32n - 1n);
+const MAX_UINT48 = 1n << (48n - 1n);
+const SOME_VALUES = [0n, 1n, 2n, 15n, 16n, 17n, 42n];
+
+const asUint = (value, size) => {
+  if (typeof value != 'bigint') {
+    value = BigInt(value);
+  }
+  // chai does not support bigint :/
+  if (value < 0 || value >= 1n << BigInt(size)) {
+    throw new Error(`value is not a valid uint${size}`);
+  }
+  return value;
+};
+
+const unpackDelay = delay => ({
+  valueBefore: (asUint(delay, 112) >> 32n) % (1n << 32n),
+  valueAfter: (asUint(delay, 112) >> 0n) % (1n << 32n),
+  effect: (asUint(delay, 112) >> 64n) % (1n << 48n),
+});
+
+const packDelay = ({ valueBefore, valueAfter = 0n, effect = 0n }) =>
+  (asUint(valueAfter, 32) << 0n) + (asUint(valueBefore, 32) << 32n) + (asUint(effect, 48) << 64n);
+
+const effectSamplesForTimepoint = timepoint => [
+  0n,
+  timepoint,
+  ...product([-1n, 1n], [1n, 2n, 17n, 42n])
+    .map(([sign, shift]) => timepoint + sign * shift)
+    .filter(effect => effect > 0n && effect <= MAX_UINT48),
+  MAX_UINT48,
+];
+
+contract('Time', function () {
+  beforeEach(async function () {
+    this.mock = await Time.new();
+  });
+
+  describe('clocks', function () {
+    it('timestamp', async function () {
+      expect(await this.mock.$timestamp()).to.be.bignumber.equal(web3.utils.toBN(await clock.timestamp()));
+    });
+
+    it('block number', async function () {
+      expect(await this.mock.$blockNumber()).to.be.bignumber.equal(web3.utils.toBN(await clock.blocknumber()));
+    });
+  });
+
+  describe('Delay', function () {
+    describe('packing and unpacking', function () {
+      const valueBefore = 17n;
+      const valueAfter = 42n;
+      const effect = 69n;
+      const delay = 1272825341158973505578n;
+
+      it('pack', async function () {
+        const packed = await this.mock.$pack(valueBefore, valueAfter, effect);
+        expect(packed).to.be.bignumber.equal(delay.toString());
+
+        const packed2 = packDelay({ valueBefore, valueAfter, effect });
+        expect(packed2).to.be.equal(delay);
+      });
+
+      it('unpack', async function () {
+        const unpacked = await this.mock.$unpack(delay);
+        expect(unpacked[0]).to.be.bignumber.equal(valueBefore.toString());
+        expect(unpacked[1]).to.be.bignumber.equal(valueAfter.toString());
+        expect(unpacked[2]).to.be.bignumber.equal(effect.toString());
+
+        const unpacked2 = unpackDelay(delay);
+        expect(unpacked2).to.be.deep.equal({ valueBefore, valueAfter, effect });
+      });
+    });
+
+    it('toDelay', async function () {
+      for (const value of [...SOME_VALUES, MAX_UINT32]) {
+        const delay = await this.mock.$toDelay(value).then(unpackDelay);
+        expect(delay).to.be.deep.equal({ valueBefore: 0n, valueAfter: value, effect: 0n });
+      }
+    });
+
+    it('getAt & getFullAt', async function () {
+      const valueBefore = 24194n;
+      const valueAfter = 4214143n;
+
+      for (const timepoint of [...SOME_VALUES, MAX_UINT48])
+        for (const effect of effectSamplesForTimepoint(timepoint)) {
+          const isPast = effect <= timepoint;
+
+          const delay = packDelay({ valueBefore, valueAfter, effect });
+
+          expect(await this.mock.$getAt(delay, timepoint)).to.be.bignumber.equal(
+            String(isPast ? valueAfter : valueBefore),
+          );
+
+          const getFullAt = await this.mock.$getFullAt(delay, timepoint);
+          expect(getFullAt[0]).to.be.bignumber.equal(String(isPast ? valueAfter : valueBefore));
+          expect(getFullAt[1]).to.be.bignumber.equal(String(isPast ? 0n : valueAfter));
+          expect(getFullAt[2]).to.be.bignumber.equal(String(isPast ? 0n : effect));
+        }
+    });
+
+    it('get & getFull', async function () {
+      const timepoint = await clock.timestamp().then(BigInt);
+      const valueBefore = 24194n;
+      const valueAfter = 4214143n;
+
+      for (const effect of effectSamplesForTimepoint(timepoint)) {
+        const isPast = effect <= timepoint;
+
+        const delay = packDelay({ valueBefore, valueAfter, effect });
+
+        expect(await this.mock.$get(delay)).to.be.bignumber.equal(String(isPast ? valueAfter : valueBefore));
+
+        const result = await this.mock.$getFull(delay);
+        expect(result[0]).to.be.bignumber.equal(String(isPast ? valueAfter : valueBefore));
+        expect(result[1]).to.be.bignumber.equal(String(isPast ? 0n : valueAfter));
+        expect(result[2]).to.be.bignumber.equal(String(isPast ? 0n : effect));
+      }
+    });
+
+    it('withUpdate', async function () {
+      const timepoint = await clock.timestamp().then(BigInt);
+      const valueBefore = 24194n;
+      const valueAfter = 4214143n;
+      const newvalueAfter = 94716n;
+
+      for (const effect of effectSamplesForTimepoint(timepoint))
+        for (const minSetback of [...SOME_VALUES, MAX_UINT32]) {
+          const isPast = effect <= timepoint;
+          const expectedvalueBefore = isPast ? valueAfter : valueBefore;
+          const expectedSetback = max(minSetback, expectedvalueBefore - newvalueAfter, 0n);
+
+          const result = await this.mock.$withUpdate(
+            packDelay({ valueBefore, valueAfter, effect }),
+            newvalueAfter,
+            minSetback,
+          );
+
+          expect(result[0]).to.be.bignumber.equal(
+            String(
+              packDelay({
+                valueBefore: expectedvalueBefore,
+                valueAfter: newvalueAfter,
+                effect: timepoint + expectedSetback,
+              }),
+            ),
+          );
+          expect(result[1]).to.be.bignumber.equal(String(timepoint + expectedSetback));
+        }
+    });
+  });
+});