From 035aebf7aabf4faecfad4e76d17c28b8ec61b8b6 Mon Sep 17 00:00:00 2001
From: MrClottom <philippe@dumo.net>
Date: Mon, 18 Jan 2021 16:33:38 +0100
Subject: [PATCH 1/3] Fix expectRevert accepting partial matches

---
 src/expectRevert.js           | 29 ++++++++++++++++++++++-------
 test/src/expectRevert.test.js |  4 ++++
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/src/expectRevert.js b/src/expectRevert.js
index 8080105..82e54cb 100644
--- a/src/expectRevert.js
+++ b/src/expectRevert.js
@@ -6,17 +6,32 @@ const semver = require('semver');
 
 const checkedProviders = new WeakSet();
 
+function getVMException (errorMessage) {
+  const VMExceptionPattern = /Returned error: VM Exception while processing transaction: (.*?)\.?$/;
+  const [, VMException] = errorMessage.match(VMExceptionPattern);
+  return VMException || null;
+}
+
+function getRevertString (VMException) {
+  const match = VMException.match(/revert (?:(?:(.*) -- Reason given: \1)|(.*))/);
+  const [, newForm, oldForm] = match;
+  return newForm || oldForm || null;
+}
+
 async function expectException (promise, expectedError) {
   try {
     await promise;
   } catch (error) {
-    if (error.message.indexOf(expectedError) === -1) {
-      // When the exception was a revert, the resulting string will include only
-      // the revert reason, otherwise it will be the type of exception (e.g. 'invalid opcode')
-      const actualError = error.message.replace(
-        /Returned error: VM Exception while processing transaction: (revert )?/,
-        '',
-      );
+    const VMException = getVMException(error.message);
+
+    if (expectedError === 'revert') {
+      // eslint-disable-next-line no-unused-expressions
+      expect(VMException.startsWith('revert'), 'Wrong kind of exception received').to.be.true;
+    } else {
+      const actualError = VMException.startsWith('revert')
+        ? getRevertString(VMException)
+        : VMException;
+
       expect(actualError).to.equal(expectedError, 'Wrong kind of exception received');
     }
     return;
diff --git a/test/src/expectRevert.test.js b/test/src/expectRevert.test.js
index 1f41d3c..5629a0d 100644
--- a/test/src/expectRevert.test.js
+++ b/test/src/expectRevert.test.js
@@ -51,6 +51,10 @@ describe('expectRevert', function () {
       await assertFailure(expectRevert(this.reverter.revertFromRequireWithReason(), 'Wrong reason'));
     });
 
+    it('rejects a failed requirement with partial error message match', async function () {
+      await assertFailure(expectRevert(this.reverter.revertFromRequireWithReason(), 'VM'));
+    });
+
     it('accepts a failed requirement with correct expected reason', async function () {
       await expectRevert(this.reverter.revertFromRequireWithReason(), 'Failed requirement');
     });

From 15fe453849af90bda87b049ba926adc7e61b46f7 Mon Sep 17 00:00:00 2001
From: MrClottom <philippe@dumo.net>
Date: Mon, 18 Jan 2021 20:16:37 +0100
Subject: [PATCH 2/3] Add alternative error message handling

---
 src/expectRevert.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/expectRevert.js b/src/expectRevert.js
index 82e54cb..c13582b 100644
--- a/src/expectRevert.js
+++ b/src/expectRevert.js
@@ -7,13 +7,20 @@ const semver = require('semver');
 const checkedProviders = new WeakSet();
 
 function getVMException (errorMessage) {
+  switch (errorMessage) {
+  case 'Returned error: Transaction reverted without a reason':
+    return 'revert';
+  }
   const VMExceptionPattern = /Returned error: VM Exception while processing transaction: (.*?)\.?$/;
-  const [, VMException] = errorMessage.match(VMExceptionPattern);
+  const match = errorMessage.match(VMExceptionPattern);
+  if (!match) throw new Error(`Unrecognized VM error string "${errorMessage}"`);
+  const [, VMException] = match;
   return VMException || null;
 }
 
 function getRevertString (VMException) {
   const match = VMException.match(/revert (?:(?:(.*) -- Reason given: \1)|(.*))/);
+  if (!match) throw new Error(`Unrecognized revert error string "${VMException}"`);
   const [, newForm, oldForm] = match;
   return newForm || oldForm || null;
 }

From 2d4ad7474e9774fba505739319b73cec3b3a4fe0 Mon Sep 17 00:00:00 2001
From: Philippe Dumonet <philippe@dumo.net>
Date: Sat, 20 Mar 2021 20:14:14 +0100
Subject: [PATCH 3/3] Add function based event validation

---
 src/expectEvent.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/expectEvent.js b/src/expectEvent.js
index bd3f120..3eb6f9c 100644
--- a/src/expectEvent.js
+++ b/src/expectEvent.js
@@ -145,8 +145,10 @@ function decodeLogs (logs, emitter, eventName) {
 
 function contains (args, key, value) {
   expect(key in args).to.equal(true, `Event argument '${key}' not found`);
-
-  if (value === null) {
+  
+  if (typeof value === 'function') {
+    value(args[key]);
+  } else if (value === null) {
     expect(args[key]).to.equal(null,
       `expected event argument '${key}' to be null but got ${args[key]}`);
   } else if (isBN(args[key]) || isBN(value)) {