feat: Check that makeInstance() returns an actual invite

Includes a test.

closes #820

packages/zoe/src/zoe.js

@@ -543,7 +543,13 @@ const makeZoe = (additionalEndowments = {}) => {
               // Once the contract is made, we add the publicAPI to the
               // contractRecord
               instanceTable.update(instanceHandle, { publicAPI });
-              return invite;
+              return inviteIssuer.isLive(invite).then(success => {
+                assert(
+                  success,
+                  details`invites must be issued by the inviteIssuer.`,
+                );
+                return invite;
+              });
             });
         };
 

packages/zoe/test/unitTests/contracts/brokenAutoRefund.js

@@ -0,0 +1,27 @@
+// @ts-check
+import harden from '@agoric/harden';
+
+/**
+ * This is a a broken contact to test zoe's error handling
+ * @type {import('@agoric/zoe').MakeContract} zoe - the contract facet of zoe
+ */
+export const makeContract = harden(zoe => {
+  const makeSeatInvite = () => {
+    const seat = harden({
+      makeOffer: () => {
+        // eslint-disable-next-line no-use-before-define
+        zoe.complete(harden([inviteHandle]));
+        return `The offer was accepted`;
+      },
+    });
+    const { invite, inviteHandle } = zoe.makeInvite(seat, {
+      seatDesc: 'getRefund',
+    });
+    return invite;
+  };
+  return harden({
+    // should be makeSeatInvite(). Intentionally wrong to provoke an error.
+    invite: makeSeatInvite,
+    publicAPI: {},
+  });
+});

packages/zoe/test/unitTests/contracts/test-brokenContract.js

@@ -0,0 +1,31 @@
+// eslint-disable-next-line import/no-extraneous-dependencies
+import { test } from 'tape-promise/tape';
+// eslint-disable-next-line import/no-extraneous-dependencies
+import bundleSource from '@agoric/bundle-source';
+
+import harden from '@agoric/harden';
+
+import { makeZoe } from '../../../src/zoe';
+// TODO: Remove setupBasicMints and rename setupBasicMints2
+import { setup } from '../setupBasicMints2';
+
+const automaticRefundRoot = `${__dirname}/brokenAutoRefund`;
+
+test.only('zoe - brokenAutomaticRefund', async t => {
+  t.plan(1);
+  // Setup zoe and mints
+  const { moolaR } = setup();
+  const zoe = makeZoe({ require });
+  // Pack the contract.
+  const { source, moduleFormat } = await bundleSource(automaticRefundRoot);
+  const installationHandle = zoe.install(source, moduleFormat);
+
+  const issuerKeywordRecord = harden({ Contribution: moolaR.issuer });
+
+  // 1: Alice tries to create an instance, but the contract is badly written.
+  t.rejects(
+    () => zoe.makeInstance(installationHandle, issuerKeywordRecord),
+    new Error('invites must be issued by InviteIssuer'),
+    'makeInstance should have thrown',
+  );
+});