From f33326161cad575a180fedcca2562973b6b5da01 Mon Sep 17 00:00:00 2001
From: Kate Sills <kate@agoric.com>
Date: Fri, 24 Apr 2020 16:26:01 -0700
Subject: [PATCH] chore: improve brand check

---
 packages/ERTP/src/amountMath.js                          | 7 +++++--
 .../test/unitTests/mathHelpers/test-natMathHelpers.js    | 9 ++++++---
 .../test/unitTests/mathHelpers/test-setMathHelpers.js    | 2 +-
 .../test/unitTests/mathHelpers/test-strSetMathHelpers.js | 2 +-
 packages/ERTP/test/unitTests/test-issuerObj.js           | 2 +-
 5 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/packages/ERTP/src/amountMath.js b/packages/ERTP/src/amountMath.js
index e5413ea73ab..2e13dbf9c21 100644
--- a/packages/ERTP/src/amountMath.js
+++ b/packages/ERTP/src/amountMath.js
@@ -2,7 +2,7 @@
 import harden from '@agoric/harden';
 import { assert, details } from '@agoric/assert';
 
-import { mustBeSameStructure, mustBeComparable } from '@agoric/same-structure';
+import { mustBeComparable } from '@agoric/same-structure';
 import mathHelpersLib from './mathHelpersLib';
 
 /**
@@ -186,7 +186,10 @@ function makeAmountMath(brand, mathHelpersName) {
         allegedBrand !== undefined,
         details`alleged brand is undefined. Did you pass an extent rather than an amount?`,
       );
-      mustBeSameStructure(brand, allegedBrand, 'Unrecognized brand');
+      assert(
+        brand === allegedBrand,
+        details`the brand in the allegedAmount in 'coerce' didn't match the amountMath brand`,
+      );
       // Will throw on inappropriate extent
       return amountMath.make(extent);
     },
diff --git a/packages/ERTP/test/unitTests/mathHelpers/test-natMathHelpers.js b/packages/ERTP/test/unitTests/mathHelpers/test-natMathHelpers.js
index 60d09ac5700..65433fa5962 100644
--- a/packages/ERTP/test/unitTests/mathHelpers/test-natMathHelpers.js
+++ b/packages/ERTP/test/unitTests/mathHelpers/test-natMathHelpers.js
@@ -10,7 +10,7 @@ import makeAmountMath from '../../../src/amountMath';
 
 const mockBrand = harden({
   isMyIssuer: () => false,
-  allegedName: () => 'mock',
+  getAllegedName: () => 'mock',
 });
 
 const amountMath = makeAmountMath(mockBrand, 'nat');
@@ -56,8 +56,11 @@ test('natMathHelpers', t => {
       `coerce can take an amount`,
     );
     t.throws(
-      () => coerce(harden({ brand: {}, extent: 4 })),
-      /Unrecognized brand/,
+      () =>
+        coerce(
+          harden({ brand: { getAllegedName: () => 'somename' }, extent: 4 }),
+        ),
+      /the brand in the allegedAmount in 'coerce' didn't match the amountMath brand/,
       `coerce can't take the wrong brand`,
     );
     t.throws(
diff --git a/packages/ERTP/test/unitTests/mathHelpers/test-setMathHelpers.js b/packages/ERTP/test/unitTests/mathHelpers/test-setMathHelpers.js
index 42457f71958..2e930fe5188 100644
--- a/packages/ERTP/test/unitTests/mathHelpers/test-setMathHelpers.js
+++ b/packages/ERTP/test/unitTests/mathHelpers/test-setMathHelpers.js
@@ -10,7 +10,7 @@ import makeAmountMath from '../../../src/amountMath';
 
 const mockBrand = harden({
   isMyIssuer: () => false,
-  allegedName: () => 'mock',
+  getAllegedName: () => 'mock',
 });
 
 const amountMath = makeAmountMath(mockBrand, 'set');
diff --git a/packages/ERTP/test/unitTests/mathHelpers/test-strSetMathHelpers.js b/packages/ERTP/test/unitTests/mathHelpers/test-strSetMathHelpers.js
index ed7572ade84..e37fb463afb 100644
--- a/packages/ERTP/test/unitTests/mathHelpers/test-strSetMathHelpers.js
+++ b/packages/ERTP/test/unitTests/mathHelpers/test-strSetMathHelpers.js
@@ -10,7 +10,7 @@ import makeAmountMath from '../../../src/amountMath';
 
 const mockBrand = harden({
   isMyIssuer: () => false,
-  allegedName: () => 'mock',
+  getAllegedName: () => 'mock',
 });
 
 const amountMath = makeAmountMath(mockBrand, 'strSet');
diff --git a/packages/ERTP/test/unitTests/test-issuerObj.js b/packages/ERTP/test/unitTests/test-issuerObj.js
index ac5226c59d2..978c5eec307 100644
--- a/packages/ERTP/test/unitTests/test-issuerObj.js
+++ b/packages/ERTP/test/unitTests/test-issuerObj.js
@@ -233,7 +233,7 @@ test('issuer.split bad amount', t => {
     const payment = mint.mintPayment(amountMath.make(1000));
     t.rejects(
       _ => E(issuer).split(payment, otherUnitOps.make(10)),
-      /Unrecognized brand/,
+      /the brand in the allegedAmount in 'coerce' didn't match the amountMath brand/,
       'throws for bad amount',
     );
   } catch (e) {