From 59aee75529e4a27789f1ea26648daac37cc191cf Mon Sep 17 00:00:00 2001
From: Do Trung Kien <trungkien.keio@gmail.com>
Date: Fri, 28 Jun 2019 13:36:25 +0700
Subject: [PATCH] use AssertionError instead assert.fail, add message
 confirmation to assertFailure

---
 src/expectRevert.js           | 8 ++++++--
 test/helpers/assertFailure.js | 4 ++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/expectRevert.js b/src/expectRevert.js
index d33d0aa..2dcc0f6 100644
--- a/src/expectRevert.js
+++ b/src/expectRevert.js
@@ -2,7 +2,7 @@ const { web3 } = require('./setup');
 
 const colors = require('ansi-colors');
 const semver = require('semver');
-const assert = require('assert');
+const AssertionError = require('assert').AssertionError;
 
 async function expectException (promise, expectedError) {
   try {
@@ -10,7 +10,11 @@ async function expectException (promise, expectedError) {
   } catch (error) {
     if (error.message.indexOf(expectedError) === -1) {
       const actualError = error.message.replace('Returned error: VM Exception while processing transaction: ', '');
-      assert.fail(`Wrong failure type, expected '${expectedError}' and got '${actualError}'`);
+      throw new AssertionError({
+        message: 'Wrong failure type',
+        expected: expectedError,
+        actual: actualError
+      });
     }
     return;
   }
diff --git a/test/helpers/assertFailure.js b/test/helpers/assertFailure.js
index f5a63c4..b220954 100644
--- a/test/helpers/assertFailure.js
+++ b/test/helpers/assertFailure.js
@@ -1,9 +1,13 @@
 const { expect } = require('chai');
+const AssertionError = require('assert').AssertionError;
 
 async function assertFailure (promise) {
   try {
     await promise;
   } catch (error) {
+    if (error instanceof AssertionError) {
+      expect(error.message).to.equal('Wrong failure type');
+    }
     return;
   }
   expect.fail();