From 73baf0b635ea1103500bae1a8ca59af1f013fbc9 Mon Sep 17 00:00:00 2001
From: "Julian M. Rodriguez" <56316686+julianmrodri@users.noreply.github.com>
Date: Wed, 6 May 2020 17:21:39 -0300
Subject: [PATCH] Feature/Adding RoleAdminChanged event in AccessControl
 (#2214)
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* Emit new event RoleAdminChanged

* Adding new RoleAdminChanged event in Tests

* Update suggested comments on new Event

Co-authored-by: Nicolás Venturo <nicolas.venturo@gmail.com>

* Adding PreviousAdminRole to event

* Update AccessControl.test.js

* Update CHANGELOG.md

Co-authored-by: Nicolás Venturo <nicolas.venturo@gmail.com>
---
 CHANGELOG.md                       |  5 +++++
 contracts/access/AccessControl.sol | 11 +++++++++++
 test/access/AccessControl.test.js  |  8 +++++++-
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d69cf231..5bccb32b5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+## 3.1.0 (unreleased)
+
+### Improvements
+ * `AccessControl`: added a `RoleAdminChanged` event to `_setAdminRole`. ([#2214](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2214))
+
 ## 3.0.1 (2020-04-27)
 
 ### Bugfixes
diff --git a/contracts/access/AccessControl.sol b/contracts/access/AccessControl.sol
index e5913be8a..8c169d959 100644
--- a/contracts/access/AccessControl.sol
+++ b/contracts/access/AccessControl.sol
@@ -52,6 +52,14 @@ abstract contract AccessControl is Context {
 
     bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
 
+    /**
+     * @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
+     *
+     * `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
+     * {RoleAdminChanged} not being emitted signaling this.
+     */
+    event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
+
     /**
      * @dev Emitted when `account` is granted `role`.
      *
@@ -183,8 +191,11 @@ abstract contract AccessControl is Context {
 
     /**
      * @dev Sets `adminRole` as ``role``'s admin role.
+     *
+     * Emits a {RoleAdminChanged} event.
      */
     function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
+        emit RoleAdminChanged(role, _roles[role].adminRole, adminRole);
         _roles[role].adminRole = adminRole;
     }
 
diff --git a/test/access/AccessControl.test.js b/test/access/AccessControl.test.js
index c49276f92..4e4424e0c 100644
--- a/test/access/AccessControl.test.js
+++ b/test/access/AccessControl.test.js
@@ -142,7 +142,13 @@ describe('AccessControl', function () {
 
   describe('setting role admin', function () {
     beforeEach(async function () {
-      await this.accessControl.setRoleAdmin(ROLE, OTHER_ROLE);
+      const receipt = await this.accessControl.setRoleAdmin(ROLE, OTHER_ROLE);
+      expectEvent(receipt, 'RoleAdminChanged', {
+        role: ROLE, 
+        previousAdminRole: DEFAULT_ADMIN_ROLE, 
+        newAdminRole: OTHER_ROLE 
+      });
+      
       await this.accessControl.grantRole(OTHER_ROLE, otherAdmin, { from: admin });
     });