feat(run-protocol): variable rate vault/loan

packages/run-protocol/src/vaultFactory/vault.js

@@ -71,12 +71,6 @@ export const makeVaultKit = (
 
   const { brand: runBrand } = runMint.getIssuerRecord();
   let runDebt = AmountMath.makeEmpty(runBrand);
-  const interestCalculator = makeInterestCalculator(
-    runBrand,
-    manager.getInterestRate(),
-    manager.getChargingPeriod(),
-    manager.getRecordingPeriod(),
-  );
 
   const getCollateralAllocated = seat =>
     seat.getAmountAllocated('Collateral', collateralBrand);
@@ -472,6 +466,13 @@ export const makeVaultKit = (
    * @returns {Amount} rate of interest used for accrual period
    */
   const accrueInterestAndAddToPool = currentTime => {
+    const interestCalculator = makeInterestCalculator(
+      runBrand,
+      manager.getInterestRate(),
+      manager.getChargingPeriod(),
+      manager.getRecordingPeriod(),
+    );
+
     const debtStatus = interestCalculator.calculateReportingPeriod(
       {
         latestInterestUpdate,

packages/run-protocol/test/vaultFactory/swingsetTests/governance/bootstrap.js

@@ -7,9 +7,10 @@ import { makeRatio } from '@agoric/zoe/src/contractSupport/index.js';
 import { INTEREST_RATE_KEY } from '../../../../src/vaultFactory/params';
 import { ONE_DAY, createCommittee, installContracts, makeVats } from '../setup';
 
-const { quote: q } = assert;
 const BASIS_POINTS = 10000n;
 
+export const daysForVoting = 3;
+
 const votersVote = async (detailsP, votersP, selections) => {
   const [voters, { positions, questionHandle }] = await Promise.all([
     votersP,
@@ -96,7 +97,6 @@ const makeBootstrap = (argv, cb, vatPowers) => async (vats, devices) => {
     governor,
     vaultFactory,
     runBrand,
-    timer,
     electorateCreatorFacet,
     electorateInstance,
     brands: [collateralBrand],
@@ -117,7 +117,9 @@ const makeBootstrap = (argv, cb, vatPowers) => async (vats, devices) => {
   ).getGovernedParams({
     collateralBrand,
   });
-  log(`param values before ${q(feeParamsStateAnte)}`);
+  log(
+    `before vote, InterestRate numerator is ${feeParamsStateAnte.InterestRate.value.numerator.value}`,
+  );
 
   const contracts = {
     vaultFactory,
@@ -132,8 +134,8 @@ const makeBootstrap = (argv, cb, vatPowers) => async (vats, devices) => {
     collateralBrand,
   };
   const counter = await setUpVote(
-    makeRatio(500n, runBrand, BASIS_POINTS),
-    3n * ONE_DAY,
+    makeRatio(4321n, runBrand, BASIS_POINTS),
+    BigInt(daysForVoting) * ONE_DAY,
     votersP,
     votes,
     interestRateParam,
@@ -147,17 +149,11 @@ const makeBootstrap = (argv, cb, vatPowers) => async (vats, devices) => {
         vaultFactory.publicFacet,
       ).getGovernedParams(interestRateParam);
       log(
-        `param values after vote on (${outcome.changeParam.parameterName}) ${q(
-          feeParamsStatePost,
-        )}`,
+        `after vote on (${outcome.changeParam.parameterName}), InterestRate numerator is ${feeParamsStatePost.InterestRate.value.numerator.value}`,
       );
     })
     .catch(e => log(`BOOT fail: ${e}`));
 
-  await E(timer).tick();
-  await E(timer).tick();
-  await E(timer).tick();
-
   await E(aliceP).startTest(testName, vaultFactory.publicFacet);
 };
 

packages/run-protocol/test/vaultFactory/swingsetTests/governance/test-governance.js

@@ -75,22 +75,30 @@ async function main(t, argv) {
 const expectedVaultFactoryLog = [
   '=> alice and the vaultFactory are set up',
   '=> voter and electorate vats are set up',
-  'param values before {"ChargingPeriod":{"type":"nat","value":"[86400n]"},"InitialMargin":{"type":"ratio","value":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[100n]"},"numerator":{"brand":"[Seen]","value":"[120n]"}}},"InterestRate":{"type":"ratio","value":{"denominator":{"brand":"[Seen]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[250n]"}}},"LiquidationMargin":{"type":"ratio","value":{"denominator":{"brand":"[Seen]","value":"[100n]"},"numerator":{"brand":"[Seen]","value":"[105n]"}}},"LoanFee":{"type":"ratio","value":{"denominator":{"brand":"[Seen]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[200n]"}}},"RecordingPeriod":{"type":"nat","value":"[86400n]"}}',
-  'Voter Bob cast a ballot for {"changeParam":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"},"proposedValue":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[500n]"}}}',
+  'before vote, InterestRate numerator is 250',
+  'Voter Bob cast a ballot for {"changeParam":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"},"proposedValue":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[4321n]"}}}',
   'Voter Carol cast a ballot for {"noChange":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"}}',
   'Voter Dave cast a ballot for {"noChange":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"}}',
-  'Voter Emma cast a ballot for {"changeParam":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"},"proposedValue":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[500n]"}}}',
-  'Voter Flora cast a ballot for {"changeParam":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"},"proposedValue":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[500n]"}}}',
+  'Voter Emma cast a ballot for {"changeParam":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"},"proposedValue":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[4321n]"}}}',
+  'Voter Flora cast a ballot for {"changeParam":{"collateralBrand":"[Alleged: moola brand]","parameterName":"InterestRate"},"proposedValue":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[4321n]"}}}',
   '=> alice.oneLoanWithInterest called',
-  'param values after vote on (InterestRate) {"ChargingPeriod":{"type":"nat","value":"[86400n]"},"InitialMargin":{"type":"ratio","value":{"denominator":{"brand":"[Alleged: RUN brand]","value":"[100n]"},"numerator":{"brand":"[Seen]","value":"[120n]"}}},"InterestRate":{"type":"ratio","value":{"denominator":{"brand":"[Seen]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[500n]"}}},"LiquidationMargin":{"type":"ratio","value":{"denominator":{"brand":"[Seen]","value":"[100n]"},"numerator":{"brand":"[Seen]","value":"[105n]"}}},"LoanFee":{"type":"ratio","value":{"denominator":{"brand":"[Seen]","value":"[10000n]"},"numerator":{"brand":"[Seen]","value":"[200n]"}}},"RecordingPeriod":{"type":"nat","value":"[86400n]"}}',
   'governor from governed matches governor instance',
   'Param "InterestRate" is in the question',
-  'Alice owes {"brand":"[Alleged: RUN brand]","value":"[510000n]"} after borrowing',
-  'Alice owes {"brand":"[Alleged: RUN brand]","value":"[510069n]"} after interest',
+  'at 0 days: Alice owes {"brand":"[Alleged: RUN brand]","value":"[510000n]"}',
+  'at 1 days: Alice owes {"brand":"[Alleged: RUN brand]","value":"[510035n]"}',
+  'at 2 days: vote ready to close',
+  'at 2 days: Alice owes {"brand":"[Alleged: RUN brand]","value":"[510070n]"}',
+  'after vote on (InterestRate), InterestRate numerator is 4321',
+  'at 3 days: vote closed',
+  'at 3 days: Alice owes {"brand":"[Alleged: RUN brand]","value":"[510105n]"}',
+  'at 3 days: 1 day after votes cast, uiNotifier update #4 has interestRate.numerator 250',
+  'at 4 days: 2 days after votes cast, uiNotifier update #5 has interestRate.numerator 4321',
+  'at 4 days: Alice owes {"brand":"[Alleged: RUN brand]","value":"[510608n]"}',
 ];
 
+// NB: yarn build if changing any of the contract bundles under test
 test.serial('vaultFactory', async t => {
-  const startingValues = [[100], [1000]];
+  const startingValues = [[100], [1000]]; // [aliceValues, ownerValues]
   const dump = await main(t, ['oneLoanWithInterest', startingValues]);
   t.deepEqual(dump.log, expectedVaultFactoryLog);
 });

packages/run-protocol/test/vaultFactory/swingsetTests/governance/vat-alice.js

@@ -3,6 +3,8 @@
 import { E } from '@agoric/eventual-send';
 import { Far } from '@agoric/marshal';
 import { AmountMath } from '@agoric/ertp';
+import { daysForVoting } from './bootstrap';
+import { ONE_DAY } from '../setup';
 
 const { details: X, quote: q } = assert;
 
@@ -12,7 +14,7 @@ const { details: X, quote: q } = assert;
  * @param {ZoeService} zoe
  * @param {Brand[]} brands
  * @param {Payment[]} payments
- * @param {ManualTimer} timer
+ * @param {ManualTimer} timer configured to tick one day (@see setup.js)
  * @returns {Promise<{startTest: Function}>}
  */
 const build = async (log, zoe, brands, payments, timer) => {
@@ -39,10 +41,38 @@ const build = async (log, zoe, brands, payments, timer) => {
       }),
     );
 
-    const { vault } = await E(loanSeat).getOfferResult();
-    log(`Alice owes ${q(await E(vault).getDebtAmount())} after borrowing`);
+    /** @type {LoanKit} */
+    const { vault, uiNotifier } = await E(loanSeat).getOfferResult();
+
+    const timeLog = async msg =>
+      log(
+        `at ${(await E(timer).getCurrentTimestamp()) / ONE_DAY} days: ${msg}`,
+      );
+
+    timeLog(`Alice owes ${q(await E(vault).getDebtAmount())}`);
+
+    // accrue one day of interest at initial rate
+    await E(timer).tick();
+    timeLog(`Alice owes ${q(await E(vault).getDebtAmount())}`);
+
+    // advance time enough that governance updates the interest rate
+    await Promise.all(new Array(daysForVoting).fill(E(timer).tick()));
+    timeLog('vote ready to close');
+    timeLog(`Alice owes ${q(await E(vault).getDebtAmount())}`);
+
+    await E(timer).tick();
+    timeLog('vote closed');
+    timeLog(`Alice owes ${q(await E(vault).getDebtAmount())}`);
+
+    const uiDescription = async () => {
+      const current = await E(uiNotifier).getUpdateSince();
+      return `uiNotifier update #${current.updateCount} has interestRate.numerator ${current.value.interestRate.numerator.value}`;
+    };
+
+    timeLog(`1 day after votes cast, ${await uiDescription()}`);
     await E(timer).tick();
-    log(`Alice owes ${q(await E(vault).getDebtAmount())} after interest`);
+    timeLog(`2 days after votes cast, ${await uiDescription()}`);
+    timeLog(`Alice owes ${q(await E(vault).getDebtAmount())}`);
   };
 
   return Far('build', {