Add Swap feature to CurrencyInput (#6091)

* Add Swap feature to CurrencyInput

* Fix linter error

* Fix and Add unit tests

7 files changed, 151 insertions, 45 deletions

diff --git a/ui/app/components/currency-input/currency-input.component.js b/ui/app/components/currency-input/currency-input.component.js
index 0761a75c5..8fa3131ae 100644
--- a/ui/app/components/currency-input/currency-input.component.js
+++ b/ui/app/components/currency-input/currency-input.component.js
@@ -17,9 +17,10 @@ export default class CurrencyInput extends PureComponent {
     nativeCurrency: PropTypes.string,
     onChange: PropTypes.func,
     onBlur: PropTypes.func,
-    suffix: PropTypes.string,
     useFiat: PropTypes.bool,
     value: PropTypes.string,
+    fiatSuffix: PropTypes.string,
+    nativeSuffix: PropTypes.string,
   }
 
   constructor (props) {
@@ -31,6 +32,7 @@ export default class CurrencyInput extends PureComponent {
     this.state = {
       decimalValue,
       hexValue,
+      isSwapped: false,
     }
   }
 
@@ -46,8 +48,8 @@ export default class CurrencyInput extends PureComponent {
   }
 
   getDecimalValue (props) {
-    const { value: hexValue, useFiat, currentCurrency, conversionRate } = props
-    const decimalValueString = useFiat
+    const { value: hexValue, currentCurrency, conversionRate } = props
+    const decimalValueString = this.shouldUseFiat()
       ? getValueFromWeiHex({
         value: hexValue, toCurrency: currentCurrency, conversionRate, numberOfDecimals: 2,
       })
@@ -58,10 +60,23 @@ export default class CurrencyInput extends PureComponent {
     return Number(decimalValueString) || 0
   }
 
+  shouldUseFiat = () => {
+    const { useFiat } = this.props
+    const { isSwapped } = this.state || {}
+    return isSwapped ? !useFiat : useFiat
+  }
+
+  swap = () => {
+    const { isSwapped, decimalValue } = this.state
+    this.setState({isSwapped: !isSwapped}, () => {
+      this.handleChange(decimalValue)
+    })
+  }
+
   handleChange = decimalValue => {
-    const { useFiat, currentCurrency: fromCurrency, conversionRate, onChange } = this.props
+    const { currentCurrency: fromCurrency, conversionRate, onChange } = this.props
 
-    const hexValue = useFiat
+    const hexValue = this.shouldUseFiat()
       ? getWeiHexFromDecimalValue({
         value: decimalValue, fromCurrency, conversionRate, invertConversionRate: true,
       })
@@ -78,11 +93,11 @@ export default class CurrencyInput extends PureComponent {
   }
 
   renderConversionComponent () {
-    const { useFiat, currentCurrency, nativeCurrency } = this.props
+    const { currentCurrency, nativeCurrency } = this.props
     const { hexValue } = this.state
     let currency, numberOfDecimals
 
-    if (useFiat) {
+    if (this.shouldUseFiat()) {
       // Display ETH
       currency = nativeCurrency || ETH
       numberOfDecimals = 6
@@ -103,19 +118,25 @@ export default class CurrencyInput extends PureComponent {
   }
 
   render () {
-    const { suffix, ...restProps } = this.props
+    const { fiatSuffix, nativeSuffix, ...restProps } = this.props
     const { decimalValue } = this.state
 
     return (
-      <UnitInput
-        {...restProps}
-        suffix={suffix}
-        onChange={this.handleChange}
-        onBlur={this.handleBlur}
-        value={decimalValue}
-      >
-        { this.renderConversionComponent() }
-      </UnitInput>
+        <UnitInput
+          {...restProps}
+          suffix={this.shouldUseFiat() ? fiatSuffix : nativeSuffix}
+          onChange={this.handleChange}
+          onBlur={this.handleBlur}
+          value={decimalValue}
+          actionComponent={(
+            <div
+              className="currency-input__swap-component"
+              onClick={this.swap}
+            />
+          )}
+        >
+          { this.renderConversionComponent() }
+        </UnitInput>
     )
   }
 }
diff --git a/ui/app/components/currency-input/currency-input.container.js b/ui/app/components/currency-input/currency-input.container.js
index 1d1ed7b41..4c89d6c1d 100644
--- a/ui/app/components/currency-input/currency-input.container.js
+++ b/ui/app/components/currency-input/currency-input.container.js
@@ -14,14 +14,13 @@ const mapStateToProps = state => {
 
 const mergeProps = (stateProps, dispatchProps, ownProps) => {
   const { nativeCurrency, currentCurrency } = stateProps
-  const { useFiat } = ownProps
-  const suffix = useFiat ? currentCurrency.toUpperCase() : nativeCurrency || ETH
 
   return {
     ...stateProps,
     ...dispatchProps,
     ...ownProps,
-    suffix,
+    nativeSuffix: nativeCurrency || ETH,
+    fiatSuffix: currentCurrency.toUpperCase(),
   }
 }
 
diff --git a/ui/app/components/currency-input/index.scss b/ui/app/components/currency-input/index.scss
index fcb2db461..f659f5b35 100644
--- a/ui/app/components/currency-input/index.scss
+++ b/ui/app/components/currency-input/index.scss
@@ -4,4 +4,23 @@
     line-height: 12px;
     padding-left: 1px;
   }
+
+  &__swap-component {
+    flex: 0 0 auto;
+    height: 24px;
+    width: 24px;
+    background-image: url("images/icons/swap.svg");
+    background-size: contain;
+    background-repeat: no-repeat;
+    cursor: pointer;
+    opacity: .4;
+
+    &:hover {
+      opacity: .3;
+    }
+
+    &:active {
+      opacity: .5;
+    }
+  }
 }
diff --git a/ui/app/components/currency-input/tests/currency-input.component.test.js b/ui/app/components/currency-input/tests/currency-input.component.test.js
index a33889f94..e1ab29187 100644
--- a/ui/app/components/currency-input/tests/currency-input.component.test.js
+++ b/ui/app/components/currency-input/tests/currency-input.component.test.js
@@ -32,7 +32,8 @@ describe('CurrencyInput Component', () => {
       const wrapper = mount(
         <Provider store={store}>
           <CurrencyInput
-            suffix="ETH"
+            nativeSuffix="ETH"
+            fiatSuffix="USD"
             nativeCurrency="ETH"
           />
         </Provider>
@@ -58,7 +59,8 @@ describe('CurrencyInput Component', () => {
         <Provider store={store}>
           <CurrencyInput
             value="de0b6b3a7640000"
-            suffix="ETH"
+            fiatSuffix="USD"
+            nativeSuffix="ETH"
             nativeCurrency="ETH"
             currentCurrency="usd"
             conversionRate={231.06}
@@ -90,7 +92,8 @@ describe('CurrencyInput Component', () => {
         <Provider store={store}>
           <CurrencyInput
             value="f602f2234d0ea"
-            suffix="USD"
+            fiatSuffix="USD"
+            nativeSuffix="ETH"
             useFiat
             nativeCurrency="ETH"
             currentCurrency="usd"
@@ -247,5 +250,56 @@ describe('CurrencyInput Component', () => {
       assert.equal(currencyInputInstance.state('hexValue'), '1ec05e43e72400')
       assert.equal(currencyInputInstance.find(UnitInput).props().value, 2)
     })
+
+    it('should swap selected currency when swap icon is clicked', () => {
+      const mockStore = {
+        metamask: {
+          nativeCurrency: 'ETH',
+          currentCurrency: 'usd',
+          conversionRate: 231.06,
+        },
+      }
+      const store = configureMockStore()(mockStore)
+      const wrapper = mount(
+        <Provider store={store}>
+          <CurrencyInput
+            onChange={handleChangeSpy}
+            onBlur={handleBlurSpy}
+            nativeSuffix="ETH"
+            fiatSuffix="USD"
+            nativeCurrency="ETH"
+            currentCurrency="usd"
+            conversionRate={231.06}
+          />
+        </Provider>
+      )
+
+      assert.ok(wrapper)
+      assert.equal(handleChangeSpy.callCount, 0)
+      assert.equal(handleBlurSpy.callCount, 0)
+
+      const currencyInputInstance = wrapper.find(CurrencyInput).at(0).instance()
+      assert.equal(currencyInputInstance.state.decimalValue, 0)
+      assert.equal(currencyInputInstance.state.hexValue, undefined)
+      assert.equal(wrapper.find('.currency-display-component').text(), '$0.00USD')
+      const input = wrapper.find('input')
+      assert.equal(input.props().value, 0)
+
+      input.simulate('change', { target: { value: 1 } })
+      assert.equal(handleChangeSpy.callCount, 1)
+      assert.ok(handleChangeSpy.calledWith('de0b6b3a7640000'))
+      assert.equal(wrapper.find('.currency-display-component').text(), '$231.06USD')
+      assert.equal(currencyInputInstance.state.decimalValue, 1)
+      assert.equal(currencyInputInstance.state.hexValue, 'de0b6b3a7640000')
+
+      assert.equal(handleBlurSpy.callCount, 0)
+      input.simulate('blur')
+      assert.equal(handleBlurSpy.callCount, 1)
+      assert.ok(handleBlurSpy.calledWith('de0b6b3a7640000'))
+
+      const swap = wrapper.find('.currency-input__swap-component')
+      swap.simulate('click')
+      assert.equal(wrapper.find('.currency-display-component').text(), '0.004328ETH')
+    })
   })
 })
diff --git a/ui/app/components/currency-input/tests/currency-input.container.test.js b/ui/app/components/currency-input/tests/currency-input.container.test.js
index 5d72958e6..10f530eff 100644
--- a/ui/app/components/currency-input/tests/currency-input.container.test.js
+++ b/ui/app/components/currency-input/tests/currency-input.container.test.js
@@ -46,14 +46,16 @@ describe('CurrencyInput container', () => {
         currentCurrency: 'usd',
         nativeCurrency: 'ETH',
         useFiat: true,
-        suffix: 'USD',
+        nativeSuffix: 'ETH',
+        fiatSuffix: 'USD',
       })
 
       assert.deepEqual(mergeProps(mockStateProps, mockDispatchProps, {}), {
         conversionRate: 280.45,
         currentCurrency: 'usd',
         nativeCurrency: 'ETH',
-        suffix: 'ETH',
+        nativeSuffix: 'ETH',
+        fiatSuffix: 'USD',
       })
     })
   })
diff --git a/ui/app/components/unit-input/index.scss b/ui/app/components/unit-input/index.scss
index 7995696aa..e4075d225 100644
--- a/ui/app/components/unit-input/index.scss
+++ b/ui/app/components/unit-input/index.scss
@@ -1,4 +1,7 @@
 .unit-input {
+  display: flex;
+  flex-flow: row nowrap;
+  align-items: center;
   min-height: 54px;
   border: 1px solid #dedede;
   border-radius: 4px;
@@ -24,6 +27,10 @@
     display: none;
   }
 
+  &__inputs {
+    flex: 1 0 auto;
+  }
+
   &__input {
     color: #4d4d4d;
     font-size: 1rem;
diff --git a/ui/app/components/unit-input/unit-input.component.js b/ui/app/components/unit-input/unit-input.component.js
index 0c6b21797..230eecfe6 100644
--- a/ui/app/components/unit-input/unit-input.component.js
+++ b/ui/app/components/unit-input/unit-input.component.js
@@ -11,6 +11,7 @@ import { removeLeadingZeroes } from '../send/send.utils'
 export default class UnitInput extends PureComponent {
   static propTypes = {
     children: PropTypes.node,
+    actionComponent: PropTypes.node,
     error: PropTypes.bool,
     onBlur: PropTypes.func,
     onChange: PropTypes.func,
@@ -70,7 +71,7 @@ export default class UnitInput extends PureComponent {
   }
 
   render () {
-    const { error, placeholder, suffix, children } = this.props
+    const { error, placeholder, suffix, actionComponent, children } = this.props
     const { value } = this.state
 
     return (
@@ -78,26 +79,29 @@ export default class UnitInput extends PureComponent {
         className={classnames('unit-input', { 'unit-input--error': error })}
         onClick={this.handleFocus}
       >
-        <div className="unit-input__input-container">
-          <input
-            type="number"
-            className="unit-input__input"
-            value={value}
-            placeholder={placeholder}
-            onChange={this.handleChange}
-            onBlur={this.handleBlur}
-            style={{ width: this.getInputWidth(value) }}
-            ref={ref => { this.unitInput = ref }}
-          />
-          {
-            suffix && (
-              <div className="unit-input__suffix">
-                { suffix }
-              </div>
-            )
-          }
+        <div className="unit-input__inputs">
+          <div className="unit-input__input-container">
+            <input
+              type="number"
+              className="unit-input__input"
+              value={value}
+              placeholder={placeholder}
+              onChange={this.handleChange}
+              onBlur={this.handleBlur}
+              style={{ width: this.getInputWidth(value) }}
+              ref={ref => { this.unitInput = ref }}
+            />
+            {
+              suffix && (
+                <div className="unit-input__suffix">
+                  { suffix }
+                </div>
+              )
+            }
+          </div>
+          { children }
         </div>
-        { children }
+        {actionComponent}
       </div>
     )
   }