1 files changed, 58 insertions, 0 deletions
diff --git a/test/unit/tx-utils-test.js b/test/unit/tx-utils-test.js
new file mode 100644
index 000000000..e57b25e83
--- /dev/null
+++ b/test/unit/tx-utils-test.js
@@ -0,0 +1,58 @@
+const assert = require('assert')
+const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
+
+const TxUtils = require('../../app/scripts/lib/tx-utils')
+
+
+describe('txUtils', function() {
+  let txUtils
+
+  before(function() {
+    txUtils = new TxUtils()
+  })
+
+  describe('addGasBuffer', function() {
+    it('multiplies by 1.5, when within block gas limit', function() {
+      // naive estimatedGas: 0x123fad (~1.2 mil)
+      const inputHex = '0x123fad'
+      // dummy gas limit: 0x3d4c52 (4 mil)
+      const blockGasLimitHex = '0x3d4c52'
+      const output = txUtils.addGasBuffer(inputHex, blockGasLimitHex)
+      const inputBn = hexToBn(inputHex)
+      const outputBn = hexToBn(output)
+      const expectedBn = inputBn.muln(1.5)
+      assert(outputBn.eq(expectedBn), 'returns 1.5 the input value')
+    })
+    
+    it('uses original estimatedGas, when above block gas limit', function() {
+      // naive estimatedGas: 0x123fad (~1.2 mil)
+      const inputHex = '0x123fad'
+      // dummy gas limit: 0x0f4240 (1 mil)
+      const blockGasLimitHex = '0x0f4240'
+      const output = txUtils.addGasBuffer(inputHex, blockGasLimitHex)
+      const inputBn = hexToBn(inputHex)
+      const outputBn = hexToBn(output)
+      const expectedBn = hexToBn(inputHex)
+      assert(outputBn.eq(expectedBn), 'returns the original estimatedGas value')
+    })
+
+    it('buffers up to block gas limit', function() {
+      // naive estimatedGas: 0x123fad (~1.2 mil)
+      const inputHex = '0x1e8480'
+      // dummy gas limit: 0x1e8480 (2 mil)
+      const blockGasLimitHex = '0x1e8480'
+      const output = txUtils.addGasBuffer(inputHex, blockGasLimitHex)
+      const inputBn = hexToBn(inputHex)
+      const outputBn = hexToBn(output)
+      const expectedBn = hexToBn(blockGasLimitHex)
+      assert(outputBn.eq(expectedBn), 'returns the block gas limit value')
+    })
+  })
+})
+
+// util
+
+function hexToBn(inputHex) {
+  return new BN(ethUtil.stripHexPrefix(inputHex), 16)
+}
+\ No newline at end of file