Fix display of primary currency symbol in send amount row

ui/app/components/send_/send-content/send-amount-row/send-amount-row.component.js

@@ -64,7 +64,7 @@ export default class SendAmountRow extends Component {
       convertedCurrency,
       gasTotal,
       inError,
-      primaryCurrency = 'ETH',
+      primaryCurrency,
       selectedToken,
     } = this.props
 
@@ -80,7 +80,7 @@ export default class SendAmountRow extends Component {
           convertedCurrency={convertedCurrency}
           handleChange={newAmount => this.handleAmountChange(newAmount)}
           inError={inError}
-          primaryCurrency={primaryCurrency}
+          primaryCurrency={primaryCurrency || 'ETH'}
           selectedToken={selectedToken}
           value={amount || '0x0'}
         />

ui/app/components/send_/send-content/send-amount-row/tests/send-amount-row-component.test.js

@@ -156,5 +156,11 @@ describe('SendAmountRow Component', function () {
         ['mockNewAmount']
       )
     })
+
+    it('should pass the default primaryCurrency to the CurrencyDisplay if primaryCurrency is falsy', () => {
+      wrapper.setProps({ primaryCurrency: null })
+      const { primaryCurrency } = wrapper.find(SendRowWrapper).childAt(1).props()
+      assert.equal(primaryCurrency, 'ETH')
+    })
   })
 })