1 files changed, 93 insertions, 0 deletions
diff --git a/test/unit/pending-balance-test.js b/test/unit/pending-balance-test.js
new file mode 100644
index 000000000..5048d487b
--- /dev/null
+++ b/test/unit/pending-balance-test.js
@@ -0,0 +1,93 @@
+const assert = require('assert')
+const PendingBalanceCalculator = require('../../app/scripts/lib/pending-balance-calculator')
+const MockTxGen = require('../lib/mock-tx-gen')
+const BN = require('ethereumjs-util').BN
+let providerResultStub = {}
+
+const zeroBn = new BN(0)
+const etherBn = new BN(String(1e18))
+const ether = '0x' + etherBn.toString(16)
+
+describe('PendingBalanceCalculator', function () {
+  let balanceCalculator
+
+  describe('#calculateMaxCost(tx)', function () {
+    it('returns a BN for a given tx value', function () {
+      const txGen = new MockTxGen()
+      pendingTxs = txGen.generate({
+        status: 'submitted',
+        txParams: {
+          value: ether,
+          gasPrice: '0x0',
+          gas: '0x0',
+        }
+      }, { count: 1 })
+
+      const balanceCalculator = generateBalanceCalcWith([], zeroBn)
+      const result = balanceCalculator.calculateMaxCost(pendingTxs[0])
+      assert.equal(result.toString(), etherBn.toString(), 'computes one ether')
+    })
+
+    it('calculates gas costs as well', function () {
+      const txGen = new MockTxGen()
+      pendingTxs = txGen.generate({
+        status: 'submitted',
+        txParams: {
+          value: '0x0',
+          gasPrice: '0x2',
+          gas: '0x3',
+        }
+      }, { count: 1 })
+
+      const balanceCalculator = generateBalanceCalcWith([], zeroBn)
+      const result = balanceCalculator.calculateMaxCost(pendingTxs[0])
+      assert.equal(result.toString(), '6', 'computes 6 wei of gas')
+    })
+  })
+
+  describe('if you have no pending txs and one ether', function () {
+
+    beforeEach(function () {
+      balanceCalculator = generateBalanceCalcWith([], etherBn)
+    })
+
+    it('returns the network balance', async function () {
+      const result = await balanceCalculator.getBalance()
+      assert.equal(result, ether, `gave ${result} needed ${ether}`)
+    })
+  })
+
+  describe('if you have a one ether pending tx and one ether', function () {
+    beforeEach(function () {
+      const txGen = new MockTxGen()
+      pendingTxs = txGen.generate({
+        status: 'submitted',
+        txParams: {
+          value: ether,
+          gasPrice: '0x0',
+          gas: '0x0',
+        }
+      }, { count: 1 })
+
+      balanceCalculator = generateBalanceCalcWith(pendingTxs, etherBn)
+    })
+
+    it('returns the subtracted result', async function () {
+      const result = await balanceCalculator.getBalance()
+      assert.equal(result, '0x0', `gave ${result} needed '0x0'`)
+      return true
+    })
+
+  })
+})
+
+function generateBalanceCalcWith (transactions, providerStub = zeroBn) {
+  const getPendingTransactions = async () => transactions
+  const getBalance = async () => providerStub
+
+  return new PendingBalanceCalculator({
+    getBalance,
+    getPendingTransactions,
+  })
+}
+