fix: adjust balance for the smallest input when creating the bundle (#94)

Author: brancoder

packages/shared/components/popups/LedgerLegacyTransaction.svelte

@@ -10,11 +10,16 @@
 
     export let transfer: Transfer
     export let inputs: Input[]
+    let balanceToAdd: number = 0
+    let smallestBalanceItem: Input | undefined
 
-    const outputAmount: number = inputs.reduce(
-        (acc, input) => acc + (input.balance < MINIMUM_MIGRATABLE_AMOUNT ? MINIMUM_MIGRATABLE_AMOUNT : input.balance),
-        0
-    )
+    if (transfer.value < MINIMUM_MIGRATABLE_AMOUNT) {
+        balanceToAdd = MINIMUM_MIGRATABLE_AMOUNT - transfer.value
+
+        smallestBalanceItem = inputs.reduce((minItem, currentItem) =>
+            currentItem.balance < minItem.balance ? currentItem : minItem
+        )
+    }
 
     // Hardcoded strings because Ledger does not translate them
     const checksumString = (checksum): string => `Chk: ${checksum}`
@@ -24,7 +29,7 @@
 
 <Text type="h4" classes="mb-6">{locale('popups.ledgerTransaction.transaction.title')}</Text>
 <Text type="p" classes="mb-6" secondary>{locale('popups.ledgerTransaction.transaction.info')}</Text>
-{#if outputAmount !== transfer.value}
+{#if smallestBalanceItem}
     <Text type="p" error classes="mb-6" secondary>{locale('popups.ledgerTransaction.transaction.warning')}</Text>
 {/if}
 
@@ -40,8 +45,8 @@
 <div class="transaction flex flex-col space-y-4 scrollable-y">
     <div class="rounded-lg bg-gray-50 dark:bg-gray-800 p-5 text-center">
         <Text type="h5" highlighted classes="mb-2">{outputString}</Text>
-        <Text type="pre">{formatUnitBestMatch(outputAmount)}</Text>
-        {#if outputAmount !== transfer.value}
+        <Text type="pre">{formatUnitBestMatch(transfer.value + balanceToAdd)}</Text>
+        {#if smallestBalanceItem}
             <Text error type="pre">
                 {locale('popups.ledgerTransaction.transaction.inputAmount', {
                     values: { amount: formatUnitBestMatch(transfer.value) },
@@ -57,9 +62,9 @@
         <div class="rounded-lg bg-gray-50 dark:bg-gray-800 p-5 text-center">
             <Text type="h5" highlighted classes="mb-2">{inputString(index)}</Text>
             <Text type="pre"
-                >{formatUnitBestMatch(balance < MINIMUM_MIGRATABLE_AMOUNT ? MINIMUM_MIGRATABLE_AMOUNT : balance)}</Text
+                >{formatUnitBestMatch(smallestBalanceItem?.index === index ? balance + balanceToAdd : balance)}</Text
             >
-            {#if balance < MINIMUM_MIGRATABLE_AMOUNT}
+            {#if smallestBalanceItem?.index === index}
                 <Text error type="pre"
                     >{locale('popups.ledgerTransaction.transaction.inputAmount', {
                         values: { amount: formatUnitBestMatch(balance) },

packages/shared/lib/migration.ts

@@ -695,36 +695,44 @@ export const createLedgerMigrationBundle = (
 ): Promise<MigrationBundle> => {
     const bundle = findMigrationBundle(bundleIndex)
 
+    let totalBalance = bundle.inputs.reduce((acc, input) => acc + input.balance, 0)
+    let balanceToAdd: number = 0
+    let smallestBalanceItem: Input | undefined
+
     const transferForConfirmation = {
         address: migrationAddress.trytes,
-        value: bundle.inputs.reduce((acc, input) => acc + input.balance, 0),
+        value: totalBalance,
         tag: 'U'.repeat(27),
     }
 
     openLedgerLegacyTransactionPopup(transferForConfirmation, bundle.inputs)
 
+    // Adjust totalBalance if its less than MINIMUM_MIGRATABLE_AMOUNT to bypass legacy validation tool in smart contract which doesnt allow migrating less than MINIMUM_MIGRATABLE_AMOUNT.
+    // The ISC only cares about the addresses in the bundle, it internaly resolves the balances and does NOT depend on the balances sent by migration tool.
+    // If the amount for migration, resolved by ISC, is less than the Min required storage deposit on stardust the receipt will contain the error messgage
+    // ex. "not enough base tokens for storage deposit: available 211188 < required 239500 base tokens"
+    if (totalBalance < MINIMUM_MIGRATABLE_AMOUNT) {
+        balanceToAdd = MINIMUM_MIGRATABLE_AMOUNT - totalBalance
+        totalBalance += balanceToAdd
+
+        smallestBalanceItem = bundle.inputs.reduce((minItem, currentItem) =>
+            currentItem.balance < minItem.balance ? currentItem : minItem
+        )
+    }
+
     const transfers = [
         {
             address: migrationAddress.trytes,
-            value: bundle.inputs.reduce(
-                (acc, input) =>
-                    acc + (input.balance < MINIMUM_MIGRATABLE_AMOUNT ? MINIMUM_MIGRATABLE_AMOUNT : input.balance),
-                0
-            ),
+            value: totalBalance,
             tag: 'U'.repeat(27),
         },
     ]
 
-    // The correct amount for migration is tracked in totalBalance and is diplayed to the user.
-    // If the totalBalance is less than the Min required storage deposit on stardust the receipt will contain the error messgage
-    // ex. "not enough base tokens for storage deposit: available 211188 < required 239500 base tokens"
-    // Hardcode MINIMUM_MIGRATABLE_AMOUNT for every input so we bypass legacy validation tool in contract which doesnt allow migrating less than MINIMUM_MIGRATABLE_AMOUNT.
-    // The ISC only cares about the addresses in the bundle, it internaly resolves the balances and does NOT depend on the amounts hardcoded here.
     const inputsForTransfer: any[] = bundle.inputs.map((input) => ({
         address: input.address,
         keyIndex: input.index,
         security: input.securityLevel,
-        balance: input.balance < MINIMUM_MIGRATABLE_AMOUNT ? MINIMUM_MIGRATABLE_AMOUNT : input.balance, // hardcoded amount
+        balance: smallestBalanceItem?.index === input.index ? input.balance + balanceToAdd : input.balance,
     }))
 
     return prepareTransfersFn(transfers, inputsForTransfer).then((trytes) => {
@@ -811,22 +819,34 @@ export const createMigrationBundle = async (bundle: Bundle, migrationAddress: Mi
 
     const prepareTransfers = createPrepareTransfers()
 
+    let totalBalance = bundle.inputs.reduce((acc, input) => acc + input.balance, 0)
+    let balanceToAdd: number = 0
+    let smallestBalanceItem: Input | undefined
+
+    // Adjust totalBalance if its less than MINIMUM_MIGRATABLE_AMOUNT to bypass legacy validation tool in smart contract which doesnt allow migrating less than MINIMUM_MIGRATABLE_AMOUNT.
+    // The ISC only cares about the addresses in the bundle, it internaly resolves the balances and does NOT depend on the balances sent by migration tool.
+    // If the amount for migration, resolved by ISC, is less than the Min required storage deposit on stardust the receipt will contain the error messgage
+    // ex. "not enough base tokens for storage deposit: available 211188 < required 239500 base tokens"
+    if (totalBalance < MINIMUM_MIGRATABLE_AMOUNT) {
+        balanceToAdd = MINIMUM_MIGRATABLE_AMOUNT - totalBalance
+        totalBalance += balanceToAdd
+
+        smallestBalanceItem = bundle.inputs.reduce((minItem, currentItem) =>
+            currentItem.balance < minItem.balance ? currentItem : minItem
+        )
+    }
     const transfers = [
         {
-            value: bundle.inputs.length * MINIMUM_MIGRATABLE_AMOUNT, // hardcoded amount
+            value: totalBalance,
             address: removeAddressChecksum(migrationAddress.trytes),
         },
     ]
-    // The correct amount for migration is tracked in totalBalance and is diplayed to the user.
-    // If the totalBalance is less than the Min required storage deposit on stardust the receipt will contain the error messgage
-    // ex. "not enough base tokens for storage deposit: available 211188 < required 239500 base tokens"
-    // Hardcode MINIMUM_MIGRATABLE_AMOUNT for every input so we bypass legacy validation tool in contract which doesnt allow migrating less than MINIMUM_MIGRATABLE_AMOUNT.
-    // The ISC only cares about the addresses in the bundle, it internaly resolves the balances and does NOT depend on the amounts hardcoded here.
+
     const inputsForTransfer: any[] = bundle.inputs.map((input) => ({
         address: input.address,
         keyIndex: input.index,
         security: input.securityLevel,
-        balance: MINIMUM_MIGRATABLE_AMOUNT, // hardcoded amount
+        balance: smallestBalanceItem?.index === input.index ? input.balance + balanceToAdd : input.balance,
     }))
 
     try {