Adds pledge and withdraw to the gasless functions.

contracts/fast/Crowdfund.sol

@@ -3,6 +3,8 @@ pragma solidity 0.8.10;
 
 import "../lib/LibAddressSet.sol";
 import "../interfaces/IERC20.sol";
+import "../common/AHasContext.sol";
+import "../common/AHasForwarder.sol";
 import "../common/AHasMembers.sol";
 import "../common/AHasGovernors.sol";
 import "@openzeppelin/contracts/utils/math/Math.sol";
@@ -11,7 +13,7 @@ import "@openzeppelin/contracts/utils/math/Math.sol";
  * @title The `Crowdfund` FAST contract.
  * @notice This contract is used to manage a crowdfunding campaign.
  */
-contract Crowdfund {
+contract Crowdfund is AHasContext {
   using LibAddressSet for LibAddressSet.Data;
 
   /// @notice Happens when a function requires an unmet phase.
@@ -118,6 +120,18 @@ contract Crowdfund {
     creationBlock = block.number;
   }
 
+  /// AHasContext implementation.
+
+  // The trusted forwarder in this instance is the parent FAST's trusted forwarder.
+  function _isTrustedForwarder(address forwarder) internal view override(AHasContext) returns (bool) {
+    return AHasForwarder(params.fast).isTrustedForwarder(forwarder);
+  }
+
+  // Override base classes to use the AHasContext implementation.
+  function _msgSender() internal view override(AHasContext) returns (address) {
+    return AHasContext._msgSender();
+  }
+
   /// @dev Given a total and a fee in basis points, returns the fee amount rounded up.
   function feeAmount() public view returns (uint256) {
     return Math.mulDiv(collected, params.basisPointsFee, 10_000, Math.Rounding.Up);
@@ -147,18 +161,18 @@ contract Crowdfund {
     // Make sure the amount is non-zero.
     if (amount == 0) revert InconsistentParameter("amount");
     // Make sure that the message sender gave us allowance for at least this amount.
-    uint256 allowance = params.token.allowance(msg.sender, address(this));
+    uint256 allowance = params.token.allowance(_msgSender(), address(this));
     if (allowance < amount) revert InsufficientFunds(amount - allowance);
     // Keep track of the pledger - don't throw if already present.
-    pledgerSet.add(msg.sender, true);
+    pledgerSet.add(_msgSender(), true);
     // Add the pledged amount to the existing pledge.
-    pledges[msg.sender] += amount;
+    pledges[_msgSender()] += amount;
     // Update the collected amount.
     collected += amount;
     // Transfer the tokens to this contract.
-    if (!params.token.transferFrom(msg.sender, address(this), amount)) revert TokenContractError();
+    if (!params.token.transferFrom(_msgSender(), address(this), amount)) revert TokenContractError();
     // Emit!
-    emit Pledge(msg.sender, amount);
+    emit Pledge(_msgSender(), amount);
   }
 
   /**
@@ -291,7 +305,7 @@ contract Crowdfund {
   }
 
   modifier onlyFastMember() {
-    if (!isFastMember(msg.sender)) revert RequiresFastMemberCaller();
+    if (!isFastMember(_msgSender())) revert RequiresFastMemberCaller();
     _;
   }
 }

contracts/fast/Distribution.sol

@@ -4,6 +4,8 @@ pragma solidity 0.8.10;
 import "../lib/LibAddressSet.sol";
 import "../lib/LibPaginate.sol";
 import "../interfaces/IERC20.sol";
+import "../common/AHasContext.sol";
+import "../common/AHasForwarder.sol";
 import "../common/AHasMembers.sol";
 import "../common/AHasAutomatons.sol";
 import "./FastAutomatonsFacet.sol";
@@ -19,7 +21,7 @@ import "./FastAutomatonsFacet.sol";
  * - Withdrawal, during which each beneficiary can withdraw their proceeds.
  * - Terminated, during which nothing is possible.
  */
-contract Distribution {
+contract Distribution is AHasContext {
   using LibAddressSet for LibAddressSet.Data;
 
   /// @notice Happens when a function requires an unmet phase.
@@ -129,6 +131,18 @@ contract Distribution {
     creationBlock = block.number;
   }
 
+  /// AHasContext implementation.
+
+  // The trusted forwarder in this instance is the parent FAST's trusted forwarder.
+  function _isTrustedForwarder(address forwarder) internal view override(AHasContext) returns (bool) {
+    return AHasForwarder(params.fast).isTrustedForwarder(forwarder);
+  }
+
+  // Override base classes to use the AHasContext implementation.
+  function _msgSender() internal view override(AHasContext) returns (address) {
+    return AHasContext._msgSender();
+  }
+
   function advanceToFeeSetup() public onlyDuring(Phase.Funding) onlyFastCaller {
     // Make sure that the current distribution has exactly the required amount locked.
     uint256 balance = params.token.balanceOf(address(this));
@@ -284,7 +298,7 @@ contract Distribution {
     // Transfer to the beneficiary all of their ownings.
     if (!params.token.transfer(beneficiary, amount)) revert TokenContractError();
     // Emit!
-    emit Withdrawal(msg.sender, beneficiary, amount);
+    emit Withdrawal(_msgSender(), beneficiary, amount);
   }
 
   /**

test/fast/Crowdfund.test.ts

@@ -5,12 +5,12 @@ import { BigNumber } from "ethers";
 import { FakeContract, smock } from "@defi-wonderland/smock";
 import { ethers } from "hardhat";
 import { SignerWithAddress } from "hardhat-deploy-ethers/signers";
-import { Crowdfund, Crowdfund__factory, IERC20 } from "../../typechain";
-import { abiStructToObj, CrowdFundPhase } from "../utils";
+import { Crowdfund, Crowdfund__factory, IERC20, IForwarder } from "../../typechain";
+import { abiStructToObj, CrowdFundPhase, impersonateContract } from "../utils";
 import {
   Fast,
   Issuer,
-  Marketplace,
+  Marketplace
 } from "../../typechain/hardhat-diamond-abi/HardhatDiamondABI.sol";
 chai.use(solidity);
 chai.use(smock.matchers);
@@ -28,11 +28,18 @@ describe("Crowdfunds", () => {
     marketplace: FakeContract<Marketplace>,
     fast: FakeContract<Fast>,
     erc20: FakeContract<IERC20>,
+    forwarder: FakeContract<IForwarder>,
     crowdfund: Crowdfund,
     crowdfundAsIssuer: Crowdfund,
     validParams: Crowdfund.ParamsStruct,
     deployCrowdfund: (params: Crowdfund.ParamsStruct) => void;
 
+  const resetIForwarderMock = () => {
+    forwarder.supportsInterface.reset();
+    forwarder.supportsInterface.whenCalledWith(/* IForwarder */ "0x25e23e64").returns(true);
+    forwarder.supportsInterface.returns(false);
+  }
+
   before(async () => {
     // Keep track of a few signers.
     [deployer, issuerMember, governor, alice, bob, paul, ben] =
@@ -45,6 +52,7 @@ describe("Crowdfunds", () => {
     marketplace = await smock.fake("Marketplace");
     fast = await smock.fake("Fast");
     erc20 = await smock.fake("IERC20");
+    forwarder = await smock.fake("IForwarder");
 
     issuer.isMember.reset();
     issuer.isMember.whenCalledWith(issuerMember.address).returns(true);
@@ -75,6 +83,8 @@ describe("Crowdfunds", () => {
     // Bob and Paul are FAST members.
     fast.isMember.whenCalledWith(bob.address).returns(true);
     fast.isMember.whenCalledWith(paul.address).returns(true);
+    // Trusted forwarder setup.
+    fast.isTrustedForwarder.whenCalledWith(forwarder.address).returns(true);
 
     erc20.balanceOf.reset();
     erc20.transfer.reset();
@@ -105,6 +115,18 @@ describe("Crowdfunds", () => {
         .deploy({ ...params, fast: fast.address });
       crowdfundAsIssuer = crowdfund.connect(issuerMember);
     };
+
+    resetIForwarderMock();
+  });
+
+  describe("AHasContext implementation", () => {
+    describe("_isTrustedForwarder", () => {
+      it("returns true if the address is a trusted forwarder");
+    });
+
+    describe("_msgSender", () => {
+      it("returns the original msg.sender");
+    });
   });
 
   describe("various synthesized getters", () => {
@@ -401,6 +423,35 @@ describe("Crowdfunds", () => {
           .to.emit(crowdfund, "Pledge")
           .withArgs(alice.address, 500);
       });
+
+      it("is callable by a trusted forwarder", async () => {
+        // Impersonate the trusted forwarder contract.
+        const crowdfundsAsForwarder = await impersonateContract(crowdfund, forwarder.address);
+
+        // Set the allowance and transferFrom to succeed.
+        erc20.allowance.returns(20);
+        erc20.transferFrom.returns(true);
+
+        // Build the data to call the sponsored function.
+        // Pack the original msg.sender address at the end - this is sponsored callers address.
+        const encodedFunctionCall = await crowdfund.interface.encodeFunctionData("pledge", [20]);
+        const data = ethers.utils.solidityPack(
+          ["bytes", "address"],
+          [encodedFunctionCall, alice.address]
+        );
+
+        // As the forwarder send the packed transaction.
+        await crowdfundsAsForwarder.signer.sendTransaction(
+          {
+            data: data,
+            to: crowdfund.address,
+          }
+        );
+
+        // Inspect the owner of the crowdfund.
+        const [pledgers] = await crowdfund.paginatePledgers(0, 2);
+        expect(pledgers).to.have.members([alice.address]);
+      });
     });
   });
 

test/fast/Distribution.test.ts

@@ -12,8 +12,9 @@ import {
   Distribution__factory,
   IERC20,
   Fast,
+  IForwarder
 } from "../../typechain";
-import { abiStructToObj, DistributionPhase } from "../utils";
+import { abiStructToObj, DistributionPhase, impersonateContract } from "../utils";
 import { FastAutomatonPrivilege } from "../../src/utils";
 chai.use(solidity);
 chai.use(smock.matchers);
@@ -32,12 +33,19 @@ describe("Distribution", () => {
     marketplace: FakeContract<Marketplace>,
     fast: FakeContract<Fast>,
     erc20: FakeContract<IERC20>,
+    forwarder: FakeContract<IForwarder>,
     distribution: Distribution,
     distributionAsIssuer: Distribution,
     distributionAsAutomaton: Distribution,
     validParams: Distribution.ParamsStruct,
     deployDistribution: (params: Distribution.ParamsStruct) => void;
 
+  const resetIForwarderMock = () => {
+    forwarder.supportsInterface.reset();
+    forwarder.supportsInterface.whenCalledWith(/* IForwarder */ "0x25e23e64").returns(true);
+    forwarder.supportsInterface.returns(false);
+  }
+
   before(async () => {
     // Keep track of a few signers.
     [deployer, issuerMember, governor, automaton, alice, bob, paul, ben] =
@@ -50,6 +58,7 @@ describe("Distribution", () => {
     marketplace = await smock.fake("Marketplace");
     fast = await smock.fake("Fast");
     erc20 = await smock.fake("IERC20");
+    forwarder = await smock.fake("IForwarder");
 
     issuer.isMember.reset();
     issuer.isMember.whenCalledWith(issuerMember.address).returns(true);
@@ -73,6 +82,8 @@ describe("Distribution", () => {
     fast.isMember.whenCalledWith(bob.address).returns(true);
     fast.isMember.whenCalledWith(paul.address).returns(true);
     fast.automatonCan.reset();
+    // Trusted forwarder setup.
+    fast.isTrustedForwarder.whenCalledWith(forwarder.address).returns(true);
 
     erc20.balanceOf.reset();
     erc20.transfer.reset();
@@ -103,6 +114,18 @@ describe("Distribution", () => {
       distributionAsIssuer = distribution.connect(issuerMember);
       distributionAsAutomaton = distribution.connect(automaton);
     };
+
+    resetIForwarderMock();
+  });
+
+  describe("AHasContext implementation", () => {
+    describe("_isTrustedForwarder", () => {
+      it("returns true if the address is a trusted forwarder");
+    });
+
+    describe("_msgSender", () => {
+      it("returns the original msg.sender");
+    });
   });
 
   describe("various synthesized getters", () => {
@@ -697,7 +720,7 @@ describe("Distribution", () => {
         it("marks the withdrawal as done", async () => {
           await distribution.withdraw(alice.address);
           const subject = await distribution.withdrawn(alice.address);
-          await expect(subject).to.eq(true);
+          expect(subject).to.eq(true);
         });
 
         it("delegates to ERC20.transfer method", async () => {
@@ -718,6 +741,30 @@ describe("Distribution", () => {
             .to.emit(distribution, "Withdrawal")
             .withArgs(deployer.address, alice.address, BigNumber.from(20));
         });
+
+        it("is callable by a trusted forwarder", async () => {
+          // Impersonate the trusted forwarder contract.
+          const crowdfundsAsForwarder = await impersonateContract(distribution, forwarder.address);
+
+          // Build the data to call the sponsored function.
+          // Pack the original msg.sender address at the end - this is sponsored callers address.
+          const encodedFunctionCall = await distribution.interface.encodeFunctionData("withdraw", [alice.address]);
+          const data = ethers.utils.solidityPack(
+            ["bytes", "address"],
+            [encodedFunctionCall, alice.address]
+          );
+
+          // As the forwarder send the packed transaction.
+          await crowdfundsAsForwarder.signer.sendTransaction(
+            {
+              data: data,
+              to: distribution.address,
+            }
+          );
+
+          const subject = await distribution.withdrawn(alice.address);
+          expect(subject).to.eq(true);
+        });
       });
     });
   });

test/marketplace/MarketplaceAccessFacet.test.ts

@@ -106,9 +106,7 @@ describe("MarketplaceAccessFacet", () => {
     });
 
     describe("_msgSender", () => {
-      it("returns the original msg.sender", async () => {
-        // Call a function on the Marketplace contract that's sponsored.
-      });
+      it("returns the original msg.sender");
     });
   });