Changed before for beforeAll, refactored Bouncer tests. (#1094)

* Changed before for beforeAll, refactored Bouncer tests.

* Fixed linter errors.

* fix: updates for SignatureBouncer tests and voucher construction

test/helpers/sign.js

@@ -1,4 +1,10 @@
 const utils = require('ethereumjs-util');
+const { soliditySha3 } = require('web3-utils');
+
+const REAL_SIGNATURE_SIZE = 2 * 65; // 65 bytes in hexadecimal string legnth
+const PADDED_SIGNATURE_SIZE = 2 * 96; // 96 bytes in hexadecimal string length
+
+const DUMMY_SIGNATURE = `0x${web3.padLeft('', REAL_SIGNATURE_SIZE)}`;
 
 /**
  * Hash and add same prefix to the hash that ganache use.
@@ -11,18 +17,63 @@ function hashMessage (message) {
   return utils.bufferToHex(utils.sha3(Buffer.concat([prefix, messageHex])));
 }
 
-// signs message using web3 (auto-applies prefix)
-function signMessage (signer, message = '', options = {}) {
-  return web3.eth.sign(signer, web3.sha3(message, options));
-}
+// signs message in node (auto-applies prefix)
+// message must be in hex already! will not be autoconverted!
+const signMessage = (signer, message = '') => {
+  return web3.eth.sign(signer, message);
+};
 
-// signs hex string using web3 (auto-applies prefix)
-function signHex (signer, message = '') {
-  return signMessage(signer, message, { encoding: 'hex' });
-}
+// @TODO - remove this when we migrate to web3-1.0.0
+const transformToFullName = function (json) {
+  if (json.name.indexOf('(') !== -1) {
+    return json.name;
+  }
+
+  var typeName = json.inputs.map(function (i) { return i.type; }).join();
+  return json.name + '(' + typeName + ')';
+};
+
+/**
+ * Create a signer between a contract and a signer for a voucher of method, args, and redeemer
+ * Note that `method` is the web3 method, not the truffle-contract method
+ * Well truffle is terrible, but luckily (?) so is web3 < 1.0, so we get to make our own method id
+ *   fetcher because the method on the contract isn't actually the SolidityFunction object ಠ_ಠ
+ * @param contract TruffleContract
+ * @param signer address
+ * @param redeemer address
+ * @param methodName string
+ * @param methodArgs any[]
+ */
+const getBouncerSigner = (contract, signer) => (redeemer, methodName, methodArgs = []) => {
+  const parts = [
+    contract.address,
+    redeemer,
+  ];
+
+  // if we have a method, add it to the parts that we're signing
+  if (methodName) {
+    if (methodArgs.length > 0) {
+      parts.push(
+        contract.contract[methodName].getData(...methodArgs.concat([DUMMY_SIGNATURE])).slice(
+          0,
+          -1 * PADDED_SIGNATURE_SIZE
+        )
+      );
+    } else {
+      const abi = contract.abi.find(abi => abi.name === methodName);
+      const name = transformToFullName(abi);
+      const signature = web3.sha3(name).slice(0, 10);
+      parts.push(signature);
+    }
+  }
+
+  // ^ substr to remove `0x` because in solidity the address is a set of byes, not a string `0xabcd`
+  const hashOfMessage = soliditySha3(...parts);
+  return signMessage(signer, hashOfMessage);
+};
 
 module.exports = {
   hashMessage,
   signMessage,
-  signHex,
+  getBouncerSigner,
 };