feat: add mocking contracts

contracts/core/defaults/WitnetRequestBoardTrustableBase.sol

@@ -37,9 +37,9 @@ abstract contract WitnetRequestBoardTrustableBase
     using WitnetV2 for WitnetV2.Response;
 
     bytes4 public immutable override specs = type(IWitnetRequestBoard).interfaceId;
-
-    WitnetRequestFactory immutable public override factory;
     WitnetBytecodes immutable public override registry;
+
+    WitnetRequestFactory immutable private __factory;
 
     modifier checkCallbackRecipient(address _addr, uint96 _callbackGasLimit) {
         require(
@@ -76,8 +76,7 @@ abstract contract WitnetRequestBoardTrustableBase
             "io.witnet.proxiable.board"
         )
     {
-        assert(address(_factory) != address(0) && address(_registry) != address(0));
-        factory = _factory;
+        __factory = _factory;
         registry = _registry;
     }
 
@@ -104,6 +103,10 @@ abstract contract WitnetRequestBoardTrustableBase
         return bytes4(keccak256(abi.encode(address(this), block.chainid)));
     }
 
+    function factory() virtual override public view returns (WitnetRequestFactory) {
+        return __factory;
+    }
+
 
     // ================================================================================================================
     // --- Yet to be implemented virtual methods ----------------------------------------------------------------------
@@ -158,16 +161,16 @@ abstract contract WitnetRequestBoardTrustableBase
         __storage().base = base();
 
         require(
-            address(factory).code.length > 0,
+            address(__factory).code.length > 0,
             "WitnetRequestBoardTrustableBase: inexistent factory"
         );
         require(
-            factory.specs() == type(IWitnetRequestFactory).interfaceId, 
+            __factory.specs() == type(IWitnetRequestFactory).interfaceId, 
             "WitnetRequestBoardTrustableBase: uncompliant factory"
         );
         require(
-            address(factory.witnet()) == address(this) 
-                && address(factory.registry()) == address(registry),
+            address(__factory.witnet()) == address(this) 
+                && address(__factory.registry()) == address(registry),
             "WitnetRequestBoardTrustableBase: discordant factory"
         );
 

contracts/core/defaults/WitnetRequestFactoryDefault.sol

@@ -60,7 +60,6 @@ contract WitnetRequestFactoryDefault
             "io.witnet.requests.factory"
         )
     {
-        assert(address(_witnet) != address(0) && address(_registry) != address(0));
         witnet = _witnet;
         registry = _registry;
         // let logic contract be used as a factory, while avoiding further initializations:

contracts/mocks/WitnetBytecodesMock.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.7.0 <0.9.0;
+pragma experimental ABIEncoderV2;
+
+import "../core/defaults/WitnetBytecodesDefault.sol";
+
+contract WitnetBytecodesMock is WitnetBytecodesDefault {
+    constructor()
+        WitnetBytecodesDefault(
+            false,
+            bytes32("mocked")
+        )
+    {}
+}

contracts/mocks/WitnetPriceFeedsMock.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.7.0 <0.9.0;
+pragma experimental ABIEncoderV2;
+
+import "../apps/WitnetPriceFeeds.sol";
+
+contract WitnetPriceFeedsMock is WitnetPriceFeeds {
+    constructor(WitnetRequestBoard _wrb)
+        WitnetPriceFeeds(
+            msg.sender,
+            _wrb
+        )
+    {}
+}

contracts/mocks/WitnetRequestBoardMock.sol

@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.7.0 <0.9.0;
+pragma experimental ABIEncoderV2;
+
+import "./WitnetRequestFactoryMock.sol";
+import "../core/defaults/WitnetRequestBoardTrustableDefault.sol";
+
+contract WitnetRequestBoardMock
+    is
+        WitnetRequestBoardTrustableDefault
+{
+    WitnetRequestFactory private __factory;
+
+    constructor(WitnetBytecodesMock _registry) 
+        WitnetRequestBoardTrustableDefault(
+            WitnetRequestFactory(address(0)), 
+            WitnetBytecodes(address(_registry)),
+            false,
+            bytes32("mocked"),
+            60000, 65000, 70000, 20000
+        )
+    {
+        __factory = WitnetRequestFactory(address(new WitnetRequestFactoryMock(_registry))); 
+    }
+
+    function factory() override public view returns (WitnetRequestFactory) {
+        return __factory;
+    }
+} 

contracts/mocks/WitnetRequestFactoryMock.sol

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity >=0.7.0 <0.9.0;
+pragma experimental ABIEncoderV2;
+
+import "./WitnetBytecodesMock.sol";
+import "../core/defaults/WitnetRequestFactoryDefault.sol";
+
+contract WitnetRequestFactoryMock
+    is 
+        WitnetRequestFactoryDefault
+{
+    constructor (WitnetBytecodesMock _registry)
+        WitnetRequestFactoryDefault(
+            WitnetRequestBoard(msg.sender),
+            WitnetBytecodes(address(_registry)),
+            false,
+            bytes32("mocked")
+        ) 
+    {}
+}