From 3ad4094040155dbc9782a57549efab4299a00288 Mon Sep 17 00:00:00 2001
From: Ricardo Guilherme Schmidt <3esmit@gmail.com>
Date: Sun, 13 May 2018 22:37:14 -0300
Subject: [PATCH] add some test utils

---
 utils/testUtils.js | 104 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 102 insertions(+), 2 deletions(-)

diff --git a/utils/testUtils.js b/utils/testUtils.js
index 13f7312..b182728 100644
--- a/utils/testUtils.js
+++ b/utils/testUtils.js
@@ -85,8 +85,6 @@ var callbackToResolve = function (resolve, reject) {
         };
 };
 
-
-
 exports.promisify = (func) =>
     (...args) => {
         return new Promise((resolve, reject) => {
@@ -95,3 +93,105 @@ exports.promisify = (func) =>
         });
     }
         
+
+// This has been tested with the real Ethereum network and Testrpc.
+// Copied and edited from: https://gist.github.com/xavierlepretre/d5583222fde52ddfbc58b7cfa0d2d0a9
+exports.assertReverts = (contractMethodCall, maxGasAvailable) => {
+    return new Promise((resolve, reject) => {
+        try {
+            resolve(contractMethodCall())
+        } catch (error) {
+            reject(error)
+        }
+    })
+        .then(tx => {
+            assert.equal(tx.receipt.gasUsed, maxGasAvailable, "tx successful, the max gas available was not consumed")
+        })
+        .catch(error => {
+            if ((error + "").indexOf("invalid opcode") < 0 && (error + "").indexOf("out of gas") < 0) {
+                // Checks if the error is from TestRpc. If it is then ignore it.
+                // Otherwise relay/throw the error produced by the above assertion.
+                // Note that no error is thrown when using a real Ethereum network AND the assertion above is true.
+                throw error
+            }
+        })
+}
+
+exports.listenForEvent = event => new Promise((resolve, reject) => {
+    event({}, (error, response) => {
+        if (!error) {
+            resolve(response.args)
+        } else {
+            reject(error)
+        }
+        event.stopWatching()
+    })
+});
+
+exports.eventValues = (receipt, eventName) => {
+    if(receipt.events[eventName])
+        return receipt.events[eventName].returnValues;
+}
+
+exports.addressToBytes32 = (address) => {
+    const stringed = "0000000000000000000000000000000000000000000000000000000000000000" + address.slice(2);
+    return "0x" + stringed.substring(stringed.length - 64, stringed.length); 
+}
+
+
+// OpenZeppelin's expectThrow helper -
+// Source: https://github.com/OpenZeppelin/zeppelin-solidity/blob/master/test/helpers/expectThrow.js
+exports.expectThrow = async promise => {
+    try {
+      await promise;
+    } catch (error) {
+      // TODO: Check jump destination to destinguish between a throw
+      //       and an actual invalid jump.
+      const invalidOpcode = error.message.search('invalid opcode') >= 0;
+      // TODO: When we contract A calls contract B, and B throws, instead
+      //       of an 'invalid jump', we get an 'out of gas' error. How do
+      //       we distinguish this from an actual out of gas event? (The
+      //       testrpc log actually show an 'invalid jump' event.)
+      const outOfGas = error.message.search('out of gas') >= 0;
+      const revert = error.message.search('revert') >= 0;
+      assert(
+        invalidOpcode || outOfGas || revert,
+        'Expected throw, got \'' + error + '\' instead',
+      );
+      return;
+    }
+    assert.fail('Expected throw not received');
+  };
+
+exports.assertJump = (error) => {
+    assert(error.message.search('revert') > -1, 'Revert should happen');
+}
+
+var callbackToResolve = function (resolve, reject) {
+    return function (error, value) {
+            if (error) {
+                reject(error);
+            } else {
+                resolve(value);
+            }
+        };
+};
+
+exports.promisify = (func) =>
+    (...args) => {
+        return new Promise((resolve, reject) => {
+        const callback = (err, data) => err ? reject(err) : resolve(data);
+        func.apply(this, [...args, callback]);
+        });
+    }
+    
+exports.zeroAddress = '0x0000000000000000000000000000000000000000';
+
+exports.ensureException = function(error) {
+    assert(isException(error), error.toString());
+};
+
+exports.isException = function(error) {
+    let strError = error.toString();
+    return strError.includes('invalid opcode') || strError.includes('invalid JUMP') || strError.includes('revert');
+}