Add zero-amount send warning for EVM chains

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased (develop)
 
+- added: Warning confirmation when sending a zero amount on EVM chains, since the transaction still spends gas.
 - added: Remote enable/disable of gift card providers via the info server's giftCardInfo config, supporting whole-provider disabling for Phaze and Bitrefill and per-brand disabling for Phaze.
 
 ## 4.49.0 (staging)

src/__tests__/modals/__snapshots__/AccelerateTxModal.test.tsx.snap

@@ -619,6 +619,7 @@ exports[`AccelerateTxModalComponent should render with loading props 1`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}

src/__tests__/scenes/__snapshots__/SendScene2.ui.test.tsx.snap

@@ -1705,6 +1705,7 @@ exports[`SendScene2 1 spendTarget 1`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -3714,6 +3715,7 @@ exports[`SendScene2 1 spendTarget with info tiles 1`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -5723,6 +5725,7 @@ exports[`SendScene2 2 spendTargets 1`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -7313,6 +7316,7 @@ exports[`SendScene2 2 spendTargets hide tiles 1`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -8883,6 +8887,7 @@ exports[`SendScene2 2 spendTargets hide tiles 2`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -10220,6 +10225,7 @@ exports[`SendScene2 2 spendTargets hide tiles 3`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -11970,6 +11976,7 @@ exports[`SendScene2 2 spendTargets lock tiles 1`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -13671,6 +13678,7 @@ exports[`SendScene2 2 spendTargets lock tiles 2`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}
@@ -15299,6 +15307,7 @@ exports[`SendScene2 2 spendTargets lock tiles 3`] = `
                 },
               ]
             }
+            testID="confirmSliderThumb"
           >
             <Text
               adjustsFontSizeToFit={true}

src/__tests__/scenes/__snapshots__/SwapConfirmationScene.test.tsx.snap

@@ -2033,6 +2033,7 @@ exports[`SwapConfirmationScene should render with loading props 1`] = `
                     },
                   ]
                 }
+                testID="confirmSliderThumb"
               >
                 <Text
                   adjustsFontSizeToFit={true}

src/components/scenes/SendScene2.tsx

@@ -1287,6 +1287,32 @@ const SendComponent: React.FC<Props> = props => {
         }
       }
 
+      // EVM chains broadcast zero-amount transactions, which still spend gas.
+      // Other chains disable the slider for zero amounts (unless allowZeroTx),
+      // so this confirmation only surfaces for EVM coin and token sends.
+      if (
+        isEvmWallet(coreWallet) &&
+        spendInfo.spendTargets.every(target => zeroString(target.nativeAmount))
+      ) {
+        const answer = await Airship.show<'continue' | 'cancel' | undefined>(
+          bridge => (
+            <ButtonsModal
+              bridge={bridge}
+              title={lstrings.send_confirmation_zero_amount_title}
+              message={lstrings.send_confirmation_zero_amount_message}
+              buttons={{
+                continue: { label: lstrings.legacy_address_modal_continue },
+                cancel: { label: lstrings.string_cancel_cap }
+              }}
+            />
+          )
+        )
+        if (answer !== 'continue') {
+          resetSlider()
+          return
+        }
+      }
+
       try {
         if (beforeTransaction != null) await beforeTransaction()
       } catch (e: unknown) {

src/components/themed/SafeSlider.tsx

@@ -120,6 +120,7 @@ export const SafeSlider: React.FC<Props> = props => {
 
         <GestureDetector gesture={gesture}>
           <Animated.View
+            testID="confirmSliderThumb"
             style={[
               styles.thumb,
               sliderDisabled ? styles.disabledThumb : null,

src/locales/en_US.ts

@@ -479,6 +479,9 @@ const strings = {
   send_confirmation_calculating_fee: 'Calculating Fee',
   send_confirmation_slide_to_confirm: 'Slide to Confirm',
   send_confirmation_balance: 'Balance',
+  send_confirmation_zero_amount_title: 'Send Zero Amount?',
+  send_confirmation_zero_amount_message:
+    "You're about to send a transaction with a zero amount. Network fees (gas) will still be charged. Are you sure you want to continue?",
   send_confirmation_algo_recipient_not_activated_s:
     'Recipient must first activate %1$s before they can receive funds.',
   send_confirmation_eos_error_cpu:

src/locales/strings/enUS.json

@@ -339,6 +339,8 @@
   "send_confirmation_calculating_fee": "Calculating Fee",
   "send_confirmation_slide_to_confirm": "Slide to Confirm",
   "send_confirmation_balance": "Balance",
+  "send_confirmation_zero_amount_title": "Send Zero Amount?",
+  "send_confirmation_zero_amount_message": "You're about to send a transaction with a zero amount. Network fees (gas) will still be charged. Are you sure you want to continue?",
   "send_confirmation_algo_recipient_not_activated_s": "Recipient must first activate %1$s before they can receive funds.",
   "send_confirmation_eos_error_cpu": "Insufficient CPU available to send EOS transaction. Please wait 1-3 days for CPU to recharge.",
   "send_confirmation_eos_error_net": "Insufficient NET available to send EOS transaction. Please wait 1-3 days for NET to recharge.",