Basic sign cheque task

hardhat.config.js

@@ -29,6 +29,13 @@ task("setupSwap", "Setup Swap")
     console.log(JSON.stringify(resp));
   });
 
+task("signCheque", "Sign cheque")
+  .setAction(async taskArgs => {
+    // TODO Argument, aliceSwapAddress
+    var resp = await swap.signCheque();
+    console.log(JSON.stringify(resp));
+  });
+
 // You need to export an object to set up your config
 // Go to https://hardhat.org/config/ to learn more
 

src/swap-helpers.js

@@ -1,3 +1,28 @@
+const eip712 = require("ethers-eip712");
+
+const EIP712Domain = [
+    { name: 'name', type: 'string' },
+    { name: 'version', type: 'string' },
+    { name: 'chainId', type: 'uint256' }
+    // Missing
+    // {name: "verifyingContract", type: "address"},
+]
+
+const ChequeType = [
+    { name: 'chequebook', type: 'address' },
+    { name: 'beneficiary', type: 'address' },
+    { name: 'cumulativePayout', type: 'uint256' }
+]
+
+// Seems to persist, first two default accounts
+var aliceAddress = "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266";
+var bobAddress = "0x70997970C51812dc3A010C7d01b50e0d17dc79C8";
+
+// XXX These change
+// TODO Parameterize
+var erc20address = "0xa513E6E4b8f2a923D98304ec87F64353C4D5C853";
+var aliceSwapAddress = "0x94099942864EA81cCF197E9D71ac53310b1468D8";
+
 async function setupSwap() {
     // Basic setup and definitions
     var signers = await ethers.getSigners();
@@ -69,4 +94,50 @@ async function setupSwap() {
     return resp;
 }
 
+// TODO This should be parameterized with arguments, so probably as a task or standalone script?
+async function signCheque() {
+    var swapAddress = aliceSwapAddress;
+    var beneficiary = bobAddress;
+    var cumulativePayout = 500;
+    var chainId = 31337;
+
+    var signers = await ethers.getSigners();
+    var aliceSigner = signers[0];
+
+    const cheque = {
+        chequebook: swapAddress,
+        beneficiary,
+        cumulativePayout: cumulativePayout
+    };
+
+    console.log("Cheque", cheque);
+
+    const types = {
+        Cheque: ChequeType
+    };
+
+    const domain = {
+        name: "Chequebook",
+        version: "1.0",
+        chainId
+    };
+
+    const value = cheque;
+
+    // XXX Workaround to get to private signTypedData interface
+    var mnemonic = "test test test test test test test test test test test junk";
+    var path0 = "m/44'/60'/0'/0/0";
+    var recoveredWallet = ethers.Wallet.fromMnemonic(mnemonic, path0);
+    var aliceSignerWallet = recoveredWallet.connect(ethers.provider);
+
+    var signature = await aliceSignerWallet._signTypedData(domain, types, value);
+
+    //console.log("Signer:", aliceSigner.address);
+    //console.log("Signature:", signature);
+
+    return {signer: aliceSigner.adress, signature: signature};
+}
+
+
 module.exports.setupSwap = setupSwap;
+module.exports.signCheque = signCheque;