Enabling toggle max to disable it again

Author: tanx

src/action/payment.js

@@ -131,8 +131,11 @@ class PaymentAction {
    * is useful for people to move their coins off of the app.
    * @return {Promise<undefined>}
    */
-  async setMax() {
+  async toggleMax() {
     const { payment, balanceSatoshis, settings } = this._store;
+    if (payment.sendAll) {
+      return this.setAmount({ amount: '0' });
+    }
     let amtSat = Math.floor(0.98 * balanceSatoshis);
     payment.amount = toAmount(amtSat, settings);
     await this.estimateFee();

src/view/pay-bitcoin.js

@@ -66,7 +66,7 @@ const PayBitcoinView = ({ store, nav, payment }) => (
           <MaxButton
             style={styles.maxBtn}
             active={store.payment.sendAll}
-            onPress={() => payment.setMax()}
+            onPress={() => payment.toggleMax()}
           />
           <InputField
             placeholder="Bitcoin Address"

test/unit/action/payment.spec.js

@@ -308,15 +308,25 @@ describe('Action Payments Unit Tests', () => {
     });
   });
 
-  describe('setMax()', () => {
+  describe('toggleMax()', () => {
     it('should set the payment amount to the wallet balance minus fee', async () => {
       store.payment.address = 'some-address';
       store.balanceSatoshis = 100000;
       grpc.sendCommand.resolves({ feeSat: 100 });
-      await payment.setMax();
+      await payment.toggleMax();
       expect(store.payment.amount, 'to match', /^0[,.]0{3}9{3}$/);
       expect(store.payment.sendAll, 'to be true');
     });
+
+    it('should disable sendAll and reset amount', async () => {
+      store.payment.sendAll = true;
+      store.payment.amount = 1000;
+      store.payment.address = 'some-address';
+      store.balanceSatoshis = 100000;
+      await payment.toggleMax();
+      expect(store.payment.amount, 'to be', '0');
+      expect(store.payment.sendAll, 'to be false');
+    });
   });
 
   describe('payBitcoin()', () => {