refactor: make satisfiesWant/satisfiesGive compatible with Multiples

They need to return 0 or 1, so they can return a count with Multiples.

Added tests for satisfiesWant, since it's exported.

packages/zoe/src/contractFacet/offerSafety.js

@@ -7,20 +7,25 @@ import { AmountMath } from '@agoric/ertp';
  * allocationAmount greater than or equal to requiredAmount for every
  * keyword of giveOrWant?
  *
+ * To prepare for multiples, satisfiesWant and satisfiesGive return 0 or 1.
+ * isOfferSafe will still be boolean. When we have Multiples, satisfiesWant and
+ * satisfiesGive will tell how many times the offer was matched.
+ *
  * @param {AmountKeywordRecord} giveOrWant
  * @param {AmountKeywordRecord} allocation
+ * @returns {0|1}
  */
 const satisfiesInternal = (giveOrWant = {}, allocation) => {
   const isGTEByKeyword = ([keyword, requiredAmount]) => {
     // If there is no allocation for a keyword, we know the giveOrWant
     // is not satisfied without checking further.
     if (allocation[keyword] === undefined) {
-      return false;
+      return 0;
     }
     const allocationAmount = allocation[keyword];
-    return AmountMath.isGTE(allocationAmount, requiredAmount);
+    return AmountMath.isGTE(allocationAmount, requiredAmount) ? 1 : 0;
   };
-  return Object.entries(giveOrWant).every(isGTEByKeyword);
+  return Object.entries(giveOrWant).every(isGTEByKeyword) ? 1 : 0;
 };
 
 /**
@@ -77,8 +82,11 @@ const satisfiesGive = (proposal, allocation) =>
  */
 function isOfferSafe(proposal, allocation) {
   return (
-    satisfiesGive(proposal, allocation) || satisfiesWant(proposal, allocation)
+    satisfiesGive(proposal, allocation) > 0 ||
+    satisfiesWant(proposal, allocation) > 0
   );
 }
 
+harden(isOfferSafe);
+harden(satisfiesWant);
 export { isOfferSafe, satisfiesWant };

packages/zoe/src/contractSupport/zoeHelpers.js

@@ -37,12 +37,14 @@ export const assertIssuerKeywords = (zcf, expected) => {
  * check; whether the allocation constitutes a refund is not
  * checked. The update is merged with currentAllocation
  * (update's values prevailing if the keywords are the same)
- * to produce the newAllocation.
+ * to produce the newAllocation. The return value is 0 for
+ * false and 1 for true. When multiples are introduced, any
+ * positive return value will mean true.
  *
  * @param {ZCF} zcf
  * @param {ZcfSeatPartial} seat
  * @param {AmountKeywordRecord} update
- * @returns {boolean}
+ * @returns {0|1}
  */
 export const satisfies = (zcf, seat, update) => {
   const currentAllocation = seat.getCurrentAllocation();

packages/zoe/src/zoeService/types.js

@@ -182,6 +182,7 @@
  * @property {() => Promise<OR>} getOfferResult
  * @property {() => void=} tryExit
  * @property {() => Promise<boolean>} hasExited
+ * @property {() => Promise<0|1>} wasWantSatisfied
  *
  * @property {() => Promise<Allocation>} getCurrentAllocationJig
  * Labelled "Jig" because it *should* only be used for tests, though

packages/zoe/test/unitTests/test-offerSafety.js

@@ -3,7 +3,10 @@
 // eslint-disable-next-line import/no-extraneous-dependencies
 import { test } from '@agoric/zoe/tools/prepare-test-env-ava.js';
 
-import { isOfferSafe } from '../../src/contractFacet/offerSafety.js';
+import {
+  isOfferSafe,
+  satisfiesWant,
+} from '../../src/contractFacet/offerSafety.js';
 import { setup } from './setupBasicMints.js';
 
 // Potential outcomes:
@@ -34,6 +37,7 @@ test('isOfferSafe - more than want, more than give', t => {
   const amounts = harden({ A: moola(10n), B: simoleans(7n), C: bucks(8n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 1);
 });
 
 // more than want, less than give -> true
@@ -47,6 +51,7 @@ test('isOfferSafe - more than want, less than give', t => {
   const amounts = harden({ A: moola(1n), B: simoleans(7n), C: bucks(8n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 1);
 });
 
 // more than want, equal to give -> true
@@ -60,6 +65,7 @@ test('isOfferSafe - more than want, equal to give', t => {
   const amounts = harden({ A: moola(9n), B: simoleans(6n), C: bucks(7n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 1);
 });
 
 // less than want, more than give -> true
@@ -73,6 +79,7 @@ test('isOfferSafe - less than want, more than give', t => {
   const amounts = harden({ A: moola(7n), B: simoleans(9n), C: bucks(19n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 0);
 });
 
 // less than want, less than give -> false
@@ -86,6 +93,7 @@ test('isOfferSafe - less than want, less than give', t => {
   const amounts = harden({ A: moola(7n), B: simoleans(5n), C: bucks(6n) });
 
   t.falsy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 0);
 });
 
 // less than want, equal to give -> true
@@ -99,6 +107,7 @@ test('isOfferSafe - less than want, equal to give', t => {
   const amounts = harden({ A: moola(1n), B: simoleans(5n), C: bucks(7n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 0);
 });
 
 // equal to want, more than give -> true
@@ -112,6 +121,7 @@ test('isOfferSafe - equal to want, more than give', t => {
   const amounts = harden({ A: moola(2n), B: simoleans(6n), C: bucks(8n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 1);
 });
 
 // equal to want, less than give -> true
@@ -125,6 +135,7 @@ test('isOfferSafe - equal to want, less than give', t => {
   const amounts = harden({ A: moola(0n), B: simoleans(6n), C: bucks(0n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 1);
 });
 
 // equal to want, equal to give -> true
@@ -138,6 +149,7 @@ test('isOfferSafe - equal to want, equal to give', t => {
   const amounts = harden({ A: moola(1n), B: simoleans(6n), C: bucks(7n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 1);
 });
 
 test('isOfferSafe - empty proposal', t => {
@@ -146,4 +158,5 @@ test('isOfferSafe - empty proposal', t => {
   const amounts = harden({ A: moola(1n), B: simoleans(6n), C: bucks(7n) });
 
   t.truthy(isOfferSafe(proposal, amounts));
+  t.is(satisfiesWant(proposal, amounts), 1);
 });

packages/zoe/test/unitTests/zcf/test-zcf.js

@@ -1440,7 +1440,7 @@ test('wasWantSatisfied: no', async t => {
   );
 
   await zcfSeat.exit();
-  t.false(await E(userSeat).wasWantSatisfied());
+  t.is(await E(userSeat).wasWantSatisfied(), 0);
 });
 
 test('wasWantSatisfied: yes', async t => {
@@ -1460,7 +1460,7 @@ test('wasWantSatisfied: yes', async t => {
   doubloonMint.mintGains(harden({ Bonus: doubloonAmount }), zcfSeat);
 
   await zcfSeat.exit();
-  t.true(await E(userSeat).wasWantSatisfied());
+  t.is(await E(userSeat).wasWantSatisfied(), 1);
 });
 
 test('wasWantSatisfied as promise', async t => {
@@ -1479,7 +1479,7 @@ test('wasWantSatisfied as promise', async t => {
   );
 
   const outcome = E.when(E(userSeat).wasWantSatisfied(), result =>
-    t.true(result),
+    t.is(result, 1),
   );
   doubloonMint.mintGains(harden({ Bonus: doubloonAmount }), zcfSeat);