Add Proxies from OpenZeppelin SDK

contracts/mocks/ClashingImplementation.sol

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.6.0;
+
+
+/**
+ * @dev Implementation contract with an admin() function made to clash with
+ * @dev AdminUpgradeabilityProxy's to test correct functioning of the
+ * @dev Transparent Proxy feature.
+ */
+contract ClashingImplementation {
+
+  function admin() external pure returns (address) {
+    return 0x0000000000000000000000000000000011111142;
+  }
+
+  function delegatedFunction() external pure returns (bool) {
+    return true;
+  }
+}

contracts/mocks/DummyImplementation.sol

@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.6.0;
+
+abstract contract Impl {
+  function version() public pure virtual returns (string memory); 
+}
+
+contract DummyImplementation {
+  uint256 public value;
+  string public text;
+  uint256[] public values;
+
+  function initializeNonPayable() public {
+    value = 10;
+  }
+
+  function initializePayable() payable public {
+    value = 100;
+  }
+
+  function initializeNonPayable(uint256 _value) public {
+    value = _value;
+  }
+
+  function initializePayable(uint256 _value) payable public {
+    value = _value;
+  }
+
+  function initialize(uint256 _value, string memory _text, uint256[] memory _values) public {
+    value = _value;
+    text = _text;
+    values = _values;
+  }
+
+  function get() public pure returns (bool) {
+    return true;
+  }
+
+  function version() public pure virtual returns (string memory) {
+    return "V1";
+  }
+
+  function reverts() public pure {
+    require(false);
+  }
+}
+
+contract DummyImplementationV2 is DummyImplementation {
+  function migrate(uint256 newVal) payable public {
+    value = newVal;
+  }
+
+  function version() public pure override returns (string memory) {
+    return "V2";
+  }
+}

contracts/mocks/InitializableMock.sol

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.6.0;
+
+import "../proxy/Initializable.sol";
+
+/**
+ * @title InitializableMock
+ * @dev This contract is a mock to test initializable functionality
+ */
+contract InitializableMock is Initializable {
+
+  bool public initializerRan;
+  uint256 public x;
+
+  function initialize() public initializer {
+    initializerRan = true;
+  }
+
+  function initializeNested() public initializer {
+    initialize();
+  }
+
+  function initializeWithX(uint256 _x) public payable initializer {
+    x = _x;
+  }
+
+  function nonInitializable(uint256 _x) public payable {
+    x = _x;
+  }
+
+  function fail() public pure {
+    require(false, "InitializableMock forced failure");
+  }
+
+}

contracts/mocks/MultipleInheritanceInitializableMocks.sol

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.6.0;
+
+import "../proxy/Initializable.sol";
+
+// Sample contracts showing upgradeability with multiple inheritance.
+// Child contract inherits from Father and Mother contracts, and Father extends from Gramps.
+// 
+//         Human
+//       /       \
+//      |       Gramps
+//      |         |
+//    Mother    Father
+//      |         |
+//      -- Child --
+
+/**
+ * Sample base intializable contract that is a human
+ */
+contract SampleHuman is Initializable {
+  bool public isHuman;
+
+  function initialize() public initializer {
+    isHuman = true;
+  }
+}
+
+/**
+ * Sample base intializable contract that defines a field mother
+ */
+contract SampleMother is Initializable, SampleHuman {
+  uint256 public mother;
+
+  function initialize(uint256 value) public initializer virtual {
+    SampleHuman.initialize();
+    mother = value;
+  }
+}
+
+/**
+ * Sample base intializable contract that defines a field gramps
+ */
+contract SampleGramps is Initializable, SampleHuman {
+  string public gramps;
+
+  function initialize(string memory value) public initializer virtual {
+    SampleHuman.initialize();
+    gramps = value;
+  }
+}
+
+/**
+ * Sample base intializable contract that defines a field father and extends from gramps
+ */
+contract SampleFather is Initializable, SampleGramps {
+  uint256 public father;
+
+  function initialize(string memory _gramps, uint256 _father) public initializer {
+    SampleGramps.initialize(_gramps);
+    father = _father;
+  }
+}
+
+/**
+ * Child extends from mother, father (gramps)
+ */
+contract SampleChild is Initializable, SampleMother, SampleFather {
+  uint256 public child;
+
+  function initialize(uint256 _mother, string memory _gramps, uint256 _father, uint256 _child) public initializer {
+    SampleMother.initialize(_mother);
+    SampleFather.initialize(_gramps, _father);
+    child = _child;
+  }
+}

contracts/mocks/RegressionImplementation.sol

@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.6.0;
+
+import "../proxy/Initializable.sol";
+
+contract Implementation1 is Initializable {
+  uint internal _value;
+
+  function initialize() public initializer {
+  }
+
+  function setValue(uint _number) public {
+    _value = _number;
+  }
+}
+
+contract Implementation2 is Initializable {
+  uint internal _value;
+
+  function initialize() public initializer {
+  }
+
+  function setValue(uint _number) public {
+    _value = _number;
+  }
+
+  function getValue() public view returns (uint) {
+    return _value;
+  }
+}
+
+contract Implementation3 is Initializable {
+  uint internal _value;
+
+  function initialize() public initializer {
+  }
+
+  function setValue(uint _number) public {
+    _value = _number;
+  }
+
+  function getValue(uint _number) public view returns (uint) {
+    return _value + _number;
+  }
+}
+
+contract Implementation4 is Initializable {
+  uint internal _value;
+
+  function initialize() public initializer {
+  }
+
+  function setValue(uint _number) public {
+    _value = _number;
+  }
+
+  function getValue() public view returns (uint) {
+    return _value;
+  }
+
+  // solhint-disable-next-line payable-fallback
+  fallback() external {
+    _value = 1;
+  }
+}

contracts/mocks/SingleInheritanceInitializableMocks.sol

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.6.0;
+
+import "../proxy/Initializable.sol";
+
+/**
+ * @title MigratableMockV1
+ * @dev This contract is a mock to test initializable functionality through migrations
+ */
+contract MigratableMockV1 is Initializable {
+  uint256 public x;
+
+  function initialize(uint256 value) public payable initializer {
+    x = value;
+  }
+}
+
+/**
+ * @title MigratableMockV2
+ * @dev This contract is a mock to test migratable functionality with params
+ */
+contract MigratableMockV2 is MigratableMockV1 {
+  bool internal _migratedV2;
+  uint256 public y;
+
+  function migrate(uint256 value, uint256 anotherValue) public payable {
+    require(!_migratedV2);
+    x = value;
+    y = anotherValue;
+    _migratedV2 = true;
+  }
+}
+
+/**
+ * @title MigratableMockV3
+ * @dev This contract is a mock to test migratable functionality without params
+ */
+contract MigratableMockV3 is MigratableMockV2 {
+  bool internal _migratedV3;
+
+  function migrate() public payable {
+    require(!_migratedV3);
+    uint256 oldX = x;
+    x = y;
+    y = oldX;
+    _migratedV3 = true;
+  }
+}