1 files changed, 51 insertions, 0 deletions
diff --git a/test/unit/components/bn-as-decimal-input-test.js b/test/unit/components/bn-as-decimal-input-test.js
new file mode 100644
index 000000000..106b3a871
--- /dev/null
+++ b/test/unit/components/bn-as-decimal-input-test.js
@@ -0,0 +1,51 @@
+var assert = require('assert')
+
+const additions = require('react-testutils-additions')
+const h = require('react-hyperscript')
+const ReactTestUtils = require('react-addons-test-utils')
+const ethUtil = require('ethereumjs-util')
+const BN = ethUtil.BN
+
+var BnInput = require('../../../ui/app/components/bn-as-decimal-input')
+
+describe('BnInput', function () {
+  it('can tolerate a gas decimal number at a high precision', function (done) {
+    const renderer = ReactTestUtils.createRenderer()
+
+    let valueStr = '20'
+    while (valueStr.length < 20) {
+      valueStr += '0'
+    }
+    const value = new BN(valueStr, 10)
+
+    const inputStr = '2.3'
+
+    let targetStr = '23'
+    while (targetStr.length < 19) {
+      targetStr += '0'
+    }
+    const target = new BN(targetStr, 10)
+
+    const precision = 18 // ether precision
+    const scale = 18
+
+    const props = {
+      value,
+      scale,
+      precision,
+      onChange: (newBn) => {
+        assert.equal(newBn.toString(), target.toString(), 'should tolerate increase')
+        done()
+      },
+    }
+
+    const inputComponent = h(BnInput, props)
+    const component = additions.renderIntoDocument(inputComponent)
+    renderer.render(inputComponent)
+    const input = additions.find(component, 'input.hex-input')[0]
+    ReactTestUtils.Simulate.change(input, { preventDefault () {}, target: {
+      value: inputStr,
+      checkValidity () { return true } },
+    })
+  })
+})