Create tests for StandardToken

contracts/test-helpers/StandardTokenMock.sol

+pragma solidity ^0.4.0;
+import '../StandardToken.sol';
+
+// mock class using StandardToken
+contract StandardTokenMock is StandardToken {
+
+  function StandardTokenMock(address initialAccount, uint initialBalance) {
+    balances[initialAccount] = initialBalance;
+  }
+
+}

test/StandardToken.js

+contract('StandardToken', function(accounts) {
+
+  it("should return the correct allowance amount after approval", function(done) {
+    var token;
+    return StandardTokenMock.new()
+      .then(function(_token) {
+        token = _token;
+        return token.approve(accounts[1], 100);
+      })
+      .then(function() {
+        return token.allowance(accounts[0], accounts[1]);
+      })
+      .then(function(allowance) {
+        assert.equal(allowance, 100);
+      })
+      .then(done);
+  });
+
+  it("should return correct balances after transfer", function(done) {
+    var token;
+    return StandardTokenMock.new(accounts[0], 100)
+      .then(function(_token) {
+        token = _token;
+        return token.transfer(accounts[1], 100);
+      })
+      .then(function() {
+        return token.balanceOf(accounts[0]);
+      })
+      .then(function(balance) {
+        assert.equal(balance, 0);
+      })
+      .then(function() {
+        return token.balanceOf(accounts[1]);
+      })
+      .then(function(balance) {
+        assert.equal(balance, 100);
+      })
+      .then(done);
+  });
+
+  it("should throw an error when trying to transfer more than balance", function(done) {
+    var token;
+    return StandardTokenMock.new(accounts[0], 100)
+      .then(function(_token) {
+        token = _token;
+        return token.transfer(accounts[1], 101);
+      })
+      .catch(function(error) {
+        if (error.message.search('invalid JUMP') == -1) throw error
+      })
+      .then(done);
+  });
+
+  it("should return correct balances after transfering from another account", function(done) {
+    var token;
+    return StandardTokenMock.new(accounts[0], 100)
+      .then(function(_token) {
+        token = _token;
+        return token.approve(accounts[1], 100);
+      })
+      .then(function() {
+        return token.transferFrom(accounts[0], accounts[2], 100, {from: accounts[1]});
+      })
+      .then(function() {
+        return token.balanceOf(accounts[0]);
+      })
+      .then(function(balance) {
+        assert.equal(balance, 0);
+        return token.balanceOf(accounts[2]);
+      })
+      .then(function(balance) {
+        assert.equal(balance, 100)
+        return token.balanceOf(accounts[1]);
+      })
+      .then(function(balance) {
+        assert.equal(balance, 0);
+      })
+      .then(done);
+  });
+
+});